Cheatsheet, Glossary & Canonical Anchor Index

Contents

Section	Topic
1	About this volume
2	Cheatsheet 1 — band-to-wavelength quick reference
3	Cheatsheet 2 — SWR / return loss / mismatch loss conversion
4	Cheatsheet 3 — dB / dBm / dBW / dBi / dBd conversions
5	Cheatsheet 4 — ferrite mix selection by band
6	Cheatsheet 5 — BALUN topology cheats
7	Cheatsheet 6 — NanoVNA OSL calibration sequence
8	Cheatsheet 7 — coax loss per 100 ft per band
9	Cheatsheet 8 — antenna picks by Hack Tools radio
10	Cheatsheet 9 — common antenna failure modes & diagnoses
11	Cheatsheet 10 — connector frequency limits and mating
12	Cheatsheet 11 — field-deployable antenna checklist
13	Cheatsheet 12 — MPE quick-check
14	Cheatsheet 13 — decision graph: “I just got Y, what antenna first?“
15	Cheatsheet 14 — posture-by-antenna quick map
16	A-Z glossary
17	Canonical anchor index for inbound cross-deep-dive links
18	Resources

---

1. About this volume

This is the closing volume of the 33-volume Antennas deep dive — a consolidating reference appendix that strips the prose out of the first 32 volumes and leaves the parts you reach for at the bench or in the field. Three sections, each with a different job:

1. The cheatsheet cluster (Sections 2–15) — fourteen one-page field cards, dense tables, no exposition. Each card stands on its own: print to 4×6 or 5×8, laminate, drop in the go-bag or pin to the shack corkboard. The numbers come from the deep volumes; the volumes carry the derivations. When you need to know what a 9.5 dB return loss translates to in SWR while you’re staring at a NanoVNA, the cheatsheet is what you flip to — not Vol 3 (dB and dBm), which is where you learn why 9.5 dB return loss means SWR 2:1 in the first place.

2. The A-Z glossary (Section 16) — every defined term used across the series, alphabetized, each entry with a one-or-two-sentence plain-language definition, the volume where the term is treated in depth, and related terms. Useful when reading sibling deep dives that cross-link into this one and you hit a term you forgot.

3. The canonical anchor index (Section 17) — the structured cross-deep-dive link surface. Other Hack Tools deep dives (especially the RF cluster in Hacker Tradecraft Vols 13-15) and external references link inbound to specific headings in this series; this index lists the canonical anchor names so those links stay stable across edits.

Designed for both bench reference (open the consolidated HTML and search) and field deployment (print, laminate, carry). The cheatsheets are the half-pound paperback you actually use; the 32 volumes that precede this one are the four-pound textbook you keep on the shelf. Both have their place; neither replaces the other.

2. Cheatsheet 1 — band-to-wavelength quick reference

Every amateur band plus the major Part 15 / 22 / 87 / 90 bands the Hack Tools envelope touches. Half-wave, quarter-wave, and 5/8-wave lengths assume free-space (no end-effect shortening); for resonant wire antennas with insulated wire near ground, knock off ~3% per Vol 6 §3. Frequency column is band-center for amateur bands, band-edge or canonical channel for Part-15 ISM.

Band	Service	Freq (MHz)	λ (m)	λ (ft)	λ/2 (ft)	λ/4 (ft)	5λ/8 (ft)
2200 m	Amateur (LF)	0.137	2189	7182	3591	1796	4489
630 m	Amateur (MF)	0.475	631	2071	1036	518	1294
160 m	Amateur (HF)	1.9	158	518	246	123	308
80 m	Amateur (HF)	3.75	80	262	125	62	156
60 m	Amateur (HF)	5.357	56	184	87	44	109
40 m	Amateur (HF)	7.15	42	138	65	33	82
30 m	Amateur (HF)	10.125	30	97	46	23	58
20 m	Amateur (HF)	14.175	21	69	33	17	41
17 m	Amateur (HF)	18.12	17	54	26	13	32
15 m	Amateur (HF)	21.225	14	46	22	11	28
12 m	Amateur (HF)	24.94	12	39	19	9.4	23
10 m	Amateur (HF)	28.85	10	34	16	8.1	20
6 m	Amateur (VHF)	52	5.77	18.9	9.06	4.55	11.4
2 m	Amateur (VHF)	146	2.05	6.74	3.23	1.62	4.05
1.25 m	Amateur (VHF)	223.5	1.34	4.40	2.11	1.06	2.64
70 cm	Amateur (UHF)	435	0.689	2.26	1.08	0.54	1.36
33 cm	Amateur / Part 15	915	0.328	1.07	0.515	0.258	0.645
23 cm	Amateur (UHF)	1270	0.236	0.776	0.371	0.186	0.464
13 cm	Amateur / ISM	2440	0.123	0.404	0.193	0.097	0.241
9 cm	Amateur / Part 15 UNII	3450	0.087	0.286	0.137	0.069	0.171
5 cm	Amateur / Part 15 UNII	5800	0.052	0.170	0.081	0.041	0.102
3 cm	Amateur / X-band	10400	0.0288	0.094	0.045	0.023	0.057

Mnemonic shortcut: half-wave length in feet ≈ 468 / f(MHz) for wire antennas (the 468 factor folds in ~5% end-effect for hand-built wire dipoles at typical heights — see Vol 6 §5). Free-space λ/2 = 492 / f(MHz). Difference: end-effect velocity factor on real wire.

3. Cheatsheet 2 — SWR / return loss / mismatch loss conversion

Drop-in table for converting between the three views of the same impedance mismatch. See Vol 3 §8 for the derivation. Reflection coefficient |Γ| is given as magnitude only (the phase is mode-specific and not interchangeable with SWR/RL). Return loss is expressed positive (i.e. “9.5 dB RL” means S11 = −9.5 dB; the cards everyone hands out use the positive convention).

SWR	Return loss (dB)	|Γ|	Refl. power (%)	Mismatch loss (dB)
1.00	∞	0.000	0.00	0.000
1.05	32.3	0.024	0.06	0.003
1.10	26.4	0.048	0.23	0.010
1.15	23.1	0.070	0.49	0.021
1.20	20.8	0.091	0.83	0.036
1.30	17.7	0.130	1.70	0.075
1.40	15.6	0.167	2.78	0.122
1.50	14.0	0.200	4.00	0.177
1.60	12.7	0.231	5.33	0.238
1.70	11.7	0.259	6.72	0.302
1.80	10.9	0.286	8.16	0.370
1.90	10.2	0.310	9.63	0.441
2.00	9.54	0.333	11.1	0.512
2.50	7.36	0.429	18.4	0.881
3.00	6.02	0.500	25.0	1.249
3.50	5.11	0.556	30.9	1.603
4.00	4.44	0.600	36.0	1.938
4.50	3.93	0.636	40.5	2.255
5.00	3.52	0.667	44.4	2.553
6.00	2.92	0.714	51.0	3.099
7.00	2.50	0.750	56.3	3.586
8.00	2.18	0.778	60.5	4.022
9.00	1.94	0.800	64.0	4.413
10.0	1.74	0.818	67.0	4.770
∞ (open/short)	0.00	1.000	100	∞

Field heuristics: RL ≥ 14 dB ≈ SWR ≤ 1.5 (broadcast / commercial spec); RL ≥ 9.5 dB ≈ SWR ≤ 2.0 (typical amateur “good enough”); RL ≥ 6 dB ≈ SWR ≤ 3.0 (autotuner’s working range); RL < 6 dB means stop transmitting at full power and find the fault. The 2:1 / 9.5 dB / 0.5 dB ML / 11.1% reflected row is the canonical “ham band edge” reference — memorize it.

4. Cheatsheet 3 — dB / dBm / dBW / dBi / dBd conversions

Three sub-tables in one card: the mental-math shortcuts (Vol 3 §7), the dB-to-ratio table for fast lookup, and the dBm/W conversion ladder.

4.1 Mental-math shortcuts (the ones that pay rent)

Operation	dB	Memo
×2 power	+3 dB	”Two is three”
×4 power	+6 dB	”Four is six”
×10 power	+10 dB	”Ten is ten”
×100 power	+20 dB	(Decade additive)
×1000 power	+30 dB	”kilo = 30”
÷2 power	−3 dB	(Half = drop 3)
÷10 power	−10 dB	(Decade additive)
×2 voltage	+6 dB	(Voltage = 20·log)
×10 voltage	+20 dB	(Voltage = 20·log)

4.2 dB-to-ratio cheat table (power)

dB	Ratio	dB	Ratio
0	1.00	7	5.01
1	1.26	8	6.31
2	1.58	9	7.94
3	2.00	10	10.0
4	2.51	13	20.0
5	3.16	20	100
6	3.98	30	1000

Combining: 17 dB = 10 + 7 → 10 × 5 = 50. 23 dB = 20 + 3 → 100 × 2 = 200. 13 dB = 10 + 3 → 10 × 2 = 20. The “1 2 3 5 7 10” approximation (1 dB ≈ ×1.25, 2 ≈ ×1.6, 3 ≈ ×2, 5 ≈ ×3, 7 ≈ ×5, 10 = ×10) is the field shortcut; the exact-ish column above is for when you need three significant figures.

4.3 dBm → watts (in 3 dB steps)

dBm	Power	dBm	Power
−30	1 µW	+20	100 mW
−20	10 µW	+27	500 mW
−10	100 µW	+30	1 W
0	1 mW	+33	2 W
+3	2 mW	+36	4 W
+6	4 mW	+40	10 W
+10	10 mW	+43	20 W
+13	20 mW	+50	100 W
+14	25 mW	+57	500 W
+15	31.6 mW	+60	1 kW
+17	50 mW	+62	1.5 kW

dBW conversion: dBW = dBm − 30. So 0 dBW = 1 W; +30 dBW = 1 kW; +60 dBm = +30 dBW.

4.4 dBi / dBd / dBic — gain references

Reference	Definition	Conversion
dBi	Gain vs isotropic radiator	(baseline)
dBd	Gain vs half-wave dipole	dBi = dBd + 2.15
dBic	Gain vs isotropic, circular pol	(same scale as dBi for circular antennas)
dBq	Gain vs short-dipole quad (legacy)	obsolete; cited only in old MFJ datasheets

Vendor-spec trap: marketing copy quotes dBi (the bigger number); engineering papers and ARRL antenna patterns quote dBd. A “9 dBi” rubber duck is a “6.85 dBd” rubber duck — and probably neither, since rubber-duck gain claims Vol 9 §15 are mostly fiction.

See Vol 3 §6 for the full derivation and the legacy references.

5. Cheatsheet 4 — ferrite mix selection by band

Picking the right mix for a BALUN, choke, or transformer is half of getting the matching network right. From Vol 16 §10. Mixes are Fair-Rite numbers (also sold by Amidon / Palomar under the same numbering); “J” and “W” are Fair-Rite premium mixes for NiZn applications at VHF.

Mix	Material	Useful range	µ_i	Best for	Power class
31	MnZn	1 – 30 MHz	1500	HF current BALUNs, 1:1 chokes, EFHW chokes	High (mass)
43	NiZn	1 – 250 MHz	850	All-band current BALUN, 49:1 UNUN, common-mode choke; the workhorse	High
52	NiZn	1 – 30 MHz	250	Voltage BALUNs at HF, transformers	High
61	NiZn	30 – 300 MHz	125	VHF chokes, 2 m / 70 cm BALUNs	Med
67	NiZn	1 – 30 MHz	40	High-power HF (>1 kW), low loss tangent	Highest
77	MnZn	100 kHz – 2 MHz	2000	Audio, LF chokes; not for amateur RF	Low
J	NiZn	30 – 200 MHz	800	Premium VHF, broadcast TV BALUNs	Med
W	MnZn	0.5 – 5 MHz	10000	LF-only chokes; rarely amateur-relevant	Low

Application quick-pick:

• HF 1:1 current BALUN, single-band HF: mix 31 or 43. Mix 31 has lower loss at 1.8-7 MHz; mix 43 wins as you climb past 14 MHz.
• All-band HF 1:1 / 4:1 current BALUN (160-10 m): mix 43. The compromise choice.
• 49:1 EFHW UNUN: mix 43 on FT240-43 (or stacked FT140-43 for portable). Mix 52 has lower loss but narrower band.
• VHF (2 m / 70 cm) BALUN or choke: mix 61 or J. Mix 43 falls off in efficiency above ~150 MHz.
• >1 kW HF station: mix 67. The lowest loss tangent of any HF mix; the FT240-67 core is the canonical choice for high-power amplifier chokes.

Test discipline: mix selection only matters if the choke actually develops common-mode impedance in your band. Sweep the choke on a NanoVNA (Vol 24 §13) — a 1:1 current choke should show ≥1 kΩ common-mode Z across the band of interest. If it doesn’t, the mix is wrong, the turn count is wrong, or both.

6. Cheatsheet 5 — BALUN topology cheats

Quick-pick from Vol 16:

Need	Topology	Ratio	Core	Reference
Coax → half-wave dipole	1:1 current BALUN	50:50	FT240-43, ~14t bifilar	Vol 16 §5
Coax → folded dipole	4:1 current BALUN	200:50	2× FT240-43, Guanella	Vol 16 §6
Coax → OCFD (Carolina Windom)	4:1 current BALUN	200:50	2× FT240-43, Guanella	Vol 16 §6
Coax → doublet via ladder line	4:1 current BALUN at ladder	200:50 (variable)	FT240-43 + tuner needed	Vol 16 §6, Vol 17 §10
Coax → random wire (TX/RX)	9:1 UNUN	450:50	FT140-43, trifilar	Vol 16 §8
Coax → random wire (RX-only)	9:1 UNUN	450:50	FT82-43, trifilar	Vol 16 §8
Coax → EFHW (TX, 100 W)	49:1 UNUN	2450:50	FT240-43, autotransformer	Vol 16 §9
Coax → EFHW (TX, 500 W+)	49:1 UNUN	2450:50	2× stacked FT240-43	Vol 16 §9
Coax → EFHW (low-band)	64:1 UNUN	3200:50	FT240-43, more turns	Vol 16 §9
Common-mode choke on coax	1:1 current choke	(no transform)	FT240-43, 14t bifilar	Vol 16 §5
Bead choke (W2DU style)	Distributed choke	(no transform)	50× FB-43-1024 beads	Vol 16 §17
Coax → multi-band fan dipole	1:1 current BALUN	50:50	FT240-43	Vol 16 §5, Vol 7 §4
Coax → G5RV (junction)	1:1 current BALUN at coax-ladder junction	50:variable	FT240-43	Vol 7 §7, Vol 16 §5

Voltage vs current BALUN: if in doubt, use current. Voltage BALUNs (Vol 16 §7, Guanella vs Ruthroff) develop common-mode current on the coax when the antenna is asymmetric (almost always) — they only behave like a BALUN when both sides of the antenna present identical impedance. Current BALUNs are the modern default. The only place a voltage BALUN earns its keep is in legacy commercial-radio HF antennas where the antenna IS symmetric and you need the impedance step-up; in amateur work, use current.

Power-handling rule of thumb: an FT240-43 will dissipate 5-8 W of loss continuously. If your power × insertion-loss exceeds that, the core saturates and the BALUN smokes. 100 W with 0.5 dB insertion loss = 11 W reflected (mismatch-loss equivalent) — within budget. 1500 W with 1 dB insertion loss = 300 W of heat. Stack cores or move to mix 67 / FT290-67.

7. Cheatsheet 6 — NanoVNA cal sequence + sweep + Smith-chart read

The deployment-day workflow from Vol 24. Print this; tape it inside the NanoVNA’s case. One-page is the design constraint.

7.1 Pre-flight (do once per session, or per 10°C temperature change)

1. Power on. Wait 5-10 min for thermal equilibrium (NanoVNA-H V3 in particular drifts in the first 2-3 min).
2. Menu → Display → Trace → All off except CH0 LOGMAG (the simplest starting state).
3. Menu → Stimulus → Start / Stop: set the sweep band — typically 0.5–1.5× the band of interest (for a 14 MHz dipole: 10–20 MHz).
4. Menu → Stimulus → Points: 401 for accuracy, 101 for quick-look sweeps.
5. Menu → Cal → Reset. Clear any prior cal.

7.2 OSL+Through calibration (12-step sequence)

6. Menu → Cal → Calibrate. Calibration sub-menu opens.
7. Connect OPEN standard to CH0 port. (Or use a clean unterminated SMA.) Press OPEN. Wait for sweep to complete.
8. Connect SHORT standard. Press SHORT. Wait for sweep.
9. Connect LOAD (50 Ω). Press LOAD. Wait for sweep.
10. Connect THROUGH cable from CH0 to CH1. Press ISOLN if available (NanoVNA-Saver: skip, internal isolation suffices). Press THRU. Wait for sweep.
11. Press DONE. Cal is now computed.
12. Menu → Cal → Save → Save 0 (or higher slot). Cal lives across power cycles.
13. Cal sanity check: with OPEN connected, S11 should read essentially 0 dB ± 0.3 dB across the band; with LOAD, S11 should read below −40 dB.

7.3 Antenna sweep workflow

14. Connect the antenna to CH0 via the SAME cable / SAME adapter chain that was used during calibration. (Cal compensates the reference plane; changing the cable invalidates the cal.)
15. Sweep. Read center-of-band marker.
16. Marker 1 → MIN VALUE: auto-position to band-minimum SWR.

7.4 Smith-chart workflow

17. Menu → Display → Format → SMITH. Trace switches.
18. The center of the chart is 50 Ω resistive (perfect match). Top half = inductive (+jX); bottom half = capacitive (−jX). Right = open; left = short.
19. Antenna marker positions:
    • Marker at center: perfectly matched. Done.
    • Marker right of center on the real axis: antenna R too high (R > 50 Ω). Lower antenna height, shorten radials, add loading capacitance.
    • Marker left of center on the real axis: antenna R too low (R < 50 Ω). Raise antenna, lengthen radials, remove loading.
    • Marker above the real axis (top half): antenna inductive — too long. Trim wire / shorten coil tap.
    • Marker below the real axis (bottom half): antenna capacitive — too short. Lengthen wire / lower coil tap.

7.5 Tear-down

20. Disconnect at CH0 first (protects the cal). Power off. Cap the calibration standards. Cal slot persists in flash.

Re-cal triggers: new session, new cable, new band, ≥10°C ambient change, after the device has been dropped or jostled, monthly even if untouched.

8. Cheatsheet 7 — coax loss per 100 ft per band

Manufacturer-spec loss in dB per 100 ft at 25°C, dry. From Vol 5 §5. Add ~20% per 25°C above ambient (loss is temperature-dependent — the conductor IR² and dielectric tan δ both increase). Add 50-100% if the coax has been outdoors more than ~5 years and shows shield oxidation. RG-58A is the “stranded inner” variant of RG-58 — slightly more flexible, slightly more loss; specs below are for solid-conductor RG-58. LMR specs from Times Microwave datasheets; Heliax from Andrew/CommScope.

Cable	Z₀	VF	1.8 MHz	7 MHz	14 MHz	30 MHz	50 MHz	146 MHz	432 MHz	2400 MHz	5800 MHz
RG-58	50	0.66	0.5	1.2	1.7	2.5	3.3	6.0	11.0	32.0	56.0
RG-58A	50	0.66	0.5	1.3	1.8	2.7	3.5	6.4	11.7	34.0	60.0
RG-8X	50	0.78	0.4	0.9	1.3	2.0	2.6	4.7	8.6	25.0	44.0
RG-213	50	0.66	0.2	0.55	0.8	1.2	1.6	2.9	5.5	16.0	30.0
RG-214	50	0.66	0.2	0.55	0.8	1.2	1.6	2.9	5.5	16.0	30.0
LMR-240	50	0.84	0.27	0.60	0.87	1.30	1.70	3.0	5.4	13.5	22.0
LMR-400	50	0.85	0.15	0.30	0.43	0.65	0.85	1.50	2.70	6.8	11.0
LMR-600	50	0.87	0.10	0.19	0.28	0.42	0.55	0.96	1.74	4.4	7.2
Heliax LDF4-50A (1/2”)	50	0.88	0.06	0.12	0.18	0.27	0.36	0.65	1.16	2.9	4.8
Heliax LDF5-50A (7/8”)	50	0.89	0.03	0.07	0.10	0.15	0.20	0.36	0.65	1.65	2.8

Field interpretation:

• 30 ft of RG-58 at 2 m (146 MHz): 1.8 dB. You’re throwing away 33% of your power. Move to LMR-400.
• 100 ft of LMR-400 at HF (7 MHz): 0.3 dB. Negligible.
• 100 ft of LMR-400 at 2.4 GHz Wi-Fi: 6.8 dB. You’ve lost 79% of your power before the antenna sees it. Hardline territory.
• 30 ft of RG-58 at 2.4 GHz: 9.6 dB. 89% loss. The cable is the antenna.
• Connector loss adder: each PL-259/N pair is roughly 0.1-0.3 dB at HF, 0.3-0.6 dB at VHF, 0.5-1.0 dB at UHF, 1-2 dB at microwave. Three adapters at 2.4 GHz can be worse than the cable.

Mismatched-line trap: the table assumes a matched load (SWR 1:1). At SWR 3:1 with 6 dB nominal cable loss, the additional loss from re-reflections is roughly 1.5 dB — the published “matched line loss” is the floor, not the ceiling. Use NanoVNA S21 to measure the actual cable end-to-end (Vol 24 §8).

9. Cheatsheet 8 — antenna picks by Hack Tools radio

Compressed from Vol 29 §2 use-case matrix. “Best single antenna” assumes one antenna per radio for general use; specialized use-cases (a 70cm satellite Yagi for the UV-K5) override the table on a per-session basis.

Radio	Band(s)	Best single antenna	Build vs Buy	Vol
HackRF One + PortaPack	1 MHz – 6 GHz	Discone (8 ft, 25-1300 MHz) + LMR-400 + 1296 MHz log-periodic add-on	Both DIY-able	Vol 12 Vol 13
RTL-SDR V4	0.5 – 1700 MHz RX	RTL-SDR Blog mag-mount tripod kit + DX-Engineering DXE-ANT-1 fan dipole HF	Buy (kit), DIY (dipole)	Vol 9 Vol 6
Flipper Zero (sub-GHz CC1101)	300-928 MHz	Vendor 433 MHz whip + 868 MHz whip swap; no upgrade needed for the use case	Buy	Vol 9
ESP32 Marauder + AWOK	2.4 GHz	RP-SMA 6 dBi rubber duck (vendor-supplied)	Buy	Vol 9
WiFi Pineapple Mark VII + AC	2.4 / 5 GHz	Bundled Tactical antennas (8 dBi 2.4, 6 dBi 5)	Buy	Vol 13
OpenSourceSDRLab PortaRF	1 MHz – 6 GHz	Same discone + whip as HackRF; treat as HackRF sibling	Both	Vol 12
Quansheng UV-K5	144 / 430 MHz	Smiley Slim-Duck 2 m/70 cm (8” replacement)	Buy	Vol 9
Rayhunter (Orbic RC400L)	700 MHz – 2.6 GHz cellular	Stock + Proxicast 12 dBi LTE Yagi for fixed	Buy	Vol 13
Wired Hatters Banshee	2.4 / 5 GHz + sub-GHz	Bundled multi-band whips	Buy	Vol 9
PWNagotchi (Pi Zero W)	2.4 GHz	Alfa AWUS036ACS RP-SMA + 9 dBi panel	Buy	Vol 11 Vol 13
Nyan Box (3× NRF24 + ESP32)	2.4 GHz	3× short rubber ducks (vendor)	Buy	Vol 9
DSTIKE Hackheld	2.4 GHz	Onboard PCB antenna; vendor PA + 2.4 GHz rubber duck	Buy	Vol 9
AWOK Dual Touch V3	2.4 GHz	Dual 6 dBi RP-SMA rubber ducks (per-radio one)	Buy	Vol 9
Bus Pirate 6	(none — wired)	—	—	—

Repeating pattern: purpose-built handheld vendor antennas (Smiley, Comet, Diamond, Pineapple Tactical) usually win for 2 m / 70 cm / 2.4 / 5 GHz applications. DIY wins for HF dipoles, discones, EFHWs, and 50 MHz – 1.3 GHz where vendor pricing gets aggressive. The hub’s primary upgrade path: discone + LMR-400 from the bench, plus per-radio whips at the radio.

10. Cheatsheet 9 — common antenna failure modes & diagnoses

From scattered references; consolidated from Vol 22, Vol 5 §10, Vol 10 §7, Vol 11 §6, Vol 14, and field experience. Diagnose first, then fix. Symptom → likely cause → fix → relevant volume.

Symptom	Likely cause	Fix	Vol ref
SWR climbs over time, jumps with humidity	Water in coax — capillary action	Cut back 12”, reseal connector (canonical sandwich)	Vol 22 §3
RFI on the rig’s audio when antenna is up	Common-mode current on coax shield	Add 1:1 choke at feedpoint and at rig entry	Vol 16 §5, Vol 5 §10
Vertical’s SWR is high on multiple bands	Lossy / corroded / too-short radial system	Verify ≥30 quarter-wave radials at base; check connections	Vol 20 §4
EFHW SWR shifts with operator position	Counterpoise too short (or non-existent)	Add 5-10% of antenna length as counterpoise wire	Vol 10 §7, Vol 16 §16
Hot rig case, “tingling” on metal	Common-mode RF on coax shield + bad ground bond	Choke at feedpoint; verify station ground bond	Vol 5 §10, Vol 20 §6
Yagi has gain but bad SWR	Match (gamma / hairpin / T-match) detuned	Retune match per element-spacing change	Vol 11 §6
Magloop bandwidth is suddenly even narrower	Capacitor losses — Q has dropped	Inspect capacitor for arcing, corrosion, contamination	Vol 14 §3, Vol 14 §11
Coax connector arcs at 100 W	Improperly torqued, dirty, water-contaminated	Cut off connector, terminate fresh, re-seal	Vol 22 §3, Vol 5 §8
TVI complaints from neighbors	Common-mode + transmitter harmonics	Choke + low-pass filter at transmitter	Vol 5 §10, Vol 31 §11
Two resonant dips appearing close together	Trap / fan-dipole stub interaction	Re-tune one element away from the other (~5% shift)	Vol 7 §4, Vol 7 §5
EFHW resonates at half expected frequency	Wire too short or loading too tight at 49:1	Verify wire length = 0.49 × λ at lowest band; check 49:1 ratio	Vol 10 §4
Yagi’s SWR fine, but pattern is back-fire	Director and reflector swapped during install	Verify reflector (longest) toward rear of boom	Vol 11 §3
Tuner can’t find a match at 80 m on a G5RV	Ladder line is at a high-impedance node	Cut/add ladder line by 10-15 ft to move the node	Vol 7 §7, Vol 17 §10
Discone has good SWR but no signals	Co-ax connector failure (open shield)	Continuity-check shield with multimeter at both ends	Vol 12 §6
EFHW works on 40 m but not 20 m	49:1 UNUN doesn’t transform on harmonics	Use 64:1 UNUN, or verify wire is broadband EFHW geometry	Vol 16 §9

The two-multimeter test for any coax run: at the antenna end with antenna disconnected, measure shield-to-center on the rig-end of the coax. Should read open (∞ Ω) if no DC blockage (most antennas), or DC short / nothing-funny if DC-grounded antenna. Then short the antenna-end center to shield; rig-end should now read ≤1 Ω (cable continuity). This catches 80% of bad-coax failures in under 5 min.

11. Cheatsheet 10 — connector frequency limits and mating

The mating table from Vol 5 §8. “Max usable frequency” is where the connector’s impedance begins to deviate enough to matter (>5% SWR contribution); the connector still passes signal at higher frequencies but with degraded match.

Connector	Max usable	Z₀	Coupling	Weather	Mates with	Notes
PL-259 / SO-239 (UHF)	300 MHz	”Constant” (varies)	Threaded	Poor	PL-259/SO-239	1930s legacy; impedance discontinuity at all frequencies; the “ham band default” because it’s been around forever
BNC	4 GHz	50 / 75 Ω	Bayonet	Fair	BNC, with adapter to TNC	Quick-disconnect; the test-bench default
N (typical)	11 GHz	50 Ω	Threaded	Excellent (when torqued)	N	The HF/VHF/UHF outdoor standard; rated for outdoor permanent install
N (precision)	18 GHz	50 Ω	Threaded	Excellent	N	Used in test gear
TNC	11 GHz	50 / 75 Ω	Threaded	Good	TNC	”Threaded BNC”; supersedes BNC for outdoor / vibration applications
SMA	18 GHz	50 Ω	Threaded	Fair	SMA	The small-form default; rated for 500 mating cycles
SMA-RP (reverse polarity)	12.4 GHz	50 Ω	Threaded	Fair	SMA-RP	FCC-mandated polarity swap on consumer Wi-Fi; mechanically identical, electrically incompatible with SMA
SMB	4 GHz	50 / 75 Ω	Snap-on	Poor	SMB	Internal RF distribution; never field-deployed
MCX / MMCX	6 GHz	50 Ω	Snap-on	Poor	own family	RTL-SDR dongle default
7/16 DIN	7.5 GHz	50 Ω	Threaded	Excellent	7/16 DIN	High-power broadcast; rare in amateur
4.3-10	6 GHz	50 Ω	Threaded / hand-tight	Excellent	4.3-10	Modern replacement for 7/16 DIN; cellular installs

Compatibility traps:

• SMA vs SMA-RP is the silent killer: physically mates but no signal transfer (center-pin / center-socket polarity is reversed). All consumer Wi-Fi gear is RP-SMA; all amateur / measurement gear is regular SMA.
• N male / N female torque spec: 12-15 in-lb. Hand-tight is not enough; over-torque (>20 in-lb) damages the female socket.
• PL-259 above 1 GHz is throwing money away — use N or SMA.
• Adapter loss budget: a single PL-259 ↔ N adapter at 2 GHz is ~0.5-1 dB. Three of them in series at 2.4 GHz = the rubber duck might as well be off.

12. Cheatsheet 11 — field-deployable antenna checklist

Pre-deployment, on-site, and post-deployment steps. From a synthesis of Vol 21 (Mounting), Vol 22 (Weatherproofing), and Vol 24 (NanoVNA workflow).

12.1 Pre-deployment (workshop, day-of)

1. ☐ NanoVNA-sweep the antenna at the bench. Mark band-edge SWR readings.
2. ☐ Visually inspect BALUN / UNUN for water-tightness; replace amalgamating tape on any feedpoint connection >6 months old.
3. ☐ Inspect coax for kinks, jacket cuts, connector corrosion. Cut back and re-terminate if shield is green.
4. ☐ Confirm connectors are torqued (12-15 in-lb for N; 5-8 in-lb for SMA).
5. ☐ Measure final coax length; label “BAND / LENGTH / DATE” on the jacket with Sharpie / heat-shrink label.
6. ☐ Pack: NanoVNA + calibration kit, multimeter, electrical tape, amalgamating tape, dielectric grease, hand tools, climbing harness if tower work, rope + halyard.

12.2 On-site (deployment)

7. ☐ Site survey: identify nearby AC power lines, fences (potential RF coupling), neighbors’ antennas (CO-Channel interference).
8. ☐ Verify radial / counterpoise system before raising the antenna.
9. ☐ Confirm common-mode choke in place at feedpoint.
10. ☐ Ground rod within 8 ft of feedpoint, bonded to mast and to station ground per NEC 250.
11. ☐ Lightning arrestor inline between coax and station ground (PolyPhaser / Alpha Delta).
12. ☐ Connect NanoVNA at the rig-end of the coax; sweep before keying.
13. ☐ Verify SWR matches pre-deployment bench measurement (within ±20%; larger delta = installation issue).
14. ☐ Confirm common-mode current on coax with snap-on Fair-Rite mix 43 choke at the rig — listen for received-signal change as you slide the choke along the coax (the location where the choke makes maximum impact is where the current is concentrated; that’s where another choke needs to live).
15. ☐ Key the radio at low power (5-10 W) first. SWR-meter check. Climb to full power only if low-power SWR is good.
16. ☐ Verify nearby AC mains aren’t picking up RF (audio hum on the rig’s mic — turn the rig to a different band; should be silent).

12.3 Post-deployment

17. ☐ Photograph the installation from 3-4 angles before leaving the site (proves baseline state; useful for warranty / insurance / regulatory inquiry).
18. ☐ Record the as-built sweep in NanoVNA-Saver and save to project folder.
19. ☐ Note GPS coordinates of feedpoint + antenna top (for FCC Form 7460 if >200 ft AGL).
20. ☐ Schedule first water-tightness check 7-14 days after first rain at the site. After that, annually at the start of monsoon / hurricane season / spring thaw.
21. ☐ For tower work: log the work in a tower log (date, weather, climber, what was done). Insurance / liability paper trail.

13. Cheatsheet 12 — MPE quick-check

OET-65 MPE limits at common HF, VHF, UHF, and microwave amateur use. Distance is the calculated controlled-environment (occupational) safe distance from a point source at the indicated transmit power. Uncontrolled-environment distance is 5× the controlled distance (the safety factor for the general public). Values are conservative point-source approximations from Vol 31 §8; the antenna’s directivity actually reduces the off-axis exposure (a 6 dBi Yagi gives 4× more exposure in the main lobe and less elsewhere, but the OET-65 spreadsheet handles that nuance — these are the “first-pass, in-the-main-lobe” numbers).

Configuration	Freq	Power (W)	MPE controlled (m)	MPE uncontrolled (m)	Notes
100 W HF dipole, 10 m AGL	14 MHz	100	1.0	5.0	20 m band typical home station
400 W 6 m Yagi (7 elements, +12 dBi), 30 m	50 MHz	400	4.5	22.5	Contest installation
100 W 2 m mobile, car roof	146 MHz	100	1.8	9.0	Driver and passengers in vehicle; metal shell helps
50 W 70 cm HT, against face	432 MHz	5	0.05	0.25	Held at typical distance, no MPE exceedance
50 W 70 cm HT, against face	432 MHz	50	0.40	2.0	Mobile-mounted output; HT mode rarely runs >5W
1500 W HF amplifier, 1 m	14 MHz	1500	3.8	19.0	Bench measurement of antenna feedpoint
1500 W 6 m amplifier + 7-el Yagi at 30 m	50 MHz	1500	8.7	43.5	Approximate; OET-65 calculator gives precise
250 W 1296 MHz EME	1296 MHz	250	4.0	20.0	25-foot dish antennas; very specialized
5 W 2.4 GHz Wi-Fi (high gain)	2400 MHz	5	0.10	0.50	Bench test; routine compliance
1 kW microwave (10 GHz amateur)	10000 MHz	1000	1.3	6.5	Very directional dish; off-axis safe at 1m

Compliance workflow: for any TX station, you owe yourself an OET-65 calculation. ARRL hosts a free worksheet at https://www.arrl.org/rf-exposure; the FCC’s own version is OET Bulletin 65 (Aug 1997 edition). For most amateur installations <400 W with 6+ m clearance, you are massively under MPE; the calculation is a sanity check, not a constraint. For high-power VHF/UHF base stations with humans in proximity, the math matters.

14. Cheatsheet 13 — decision graph: “I just got Y, what antenna first?”

The first-antenna call by radio. Each path is “minimum viable” — the antenna that opens the radio’s principal use without spending unnecessarily.

Radio (just acquired)	Day-1 antenna	Cost	Source	Why first
HackRF One	8 ft discone (DX Engineering / vendor)	$150	Buy	Covers 25 MHz – 1.3 GHz general RX + TX experiments
RTL-SDR V4	RTL-SDR Blog v4 mag-mount tripod kit	$30	Buy	All-in-one starter; works for 24-1700 MHz RX
Flipper Zero	Stock factory antenna	$0	Owned	433/868 MHz functional from day one
ESP32 Marauder (AWOK Dual Touch)	Stock vendor antennas	$0	Owned	2.4 GHz Wi-Fi functional immediately
Quansheng UV-K5	Smiley Slim-Duck 2m/70cm (8” replacement)	$25	Buy	Doubles the stock-antenna gain on 2m
WiFi Pineapple Mark VII + AC Tactical	Tactical kit antennas (in box)	$0	Owned	All-in-one
Rayhunter (Orbic)	Stock	$0	Owned	Cellular detection works as-is
First HF amateur radio (any)	40m dipole (75 ft of 14 AWG, dipole center insulator, 1:1 BALUN)	$80-100	DIY	Covers 40m + 15m (harmonic), most active general HF
First V/U dual-bander	19” rooftop ground-plane or Diamond X-200A	$75-200	Buy	Omnidirectional coverage of 2m/70cm; FM repeater work day one
First HF QRP rig	EFHW for 40-10m (~ 65 ft wire + 49:1 UNUN)	$80	DIY (Vol 10 §13)	Single feed, multiple bands, easy to deploy from a park
First mobile HF rig	Hustler 6-BTV vertical (in driveway)	$450	Buy	80-10m without changing antennas; ground radials are the work
First contest station	A2KAK 4-square verticals or 3-el HF Yagi (whichever the budget)	$1500-5000	Buy	Above-the-noise gain for competitive operation
First moonbounce / weak-signal VHF	Cushcraft A50-5S or 5-element 6m Yagi	$300	Buy	”Real” 6m operating starts here

Universal principle: for handhelds, replace the stock antenna with a real one. For SDRs, get a discone or wideband first. For HF, build a single-band dipole resonant on the band you’ll operate most. Don’t try to make any one antenna serve all your radios — get the cheap-and-effective day-1 antenna first, then read Vol 30 (Multi-radio shared antennas) to consolidate.

15. Cheatsheet 14 — posture-by-antenna quick map

Per-antenna fitness for each operating posture. Scoring: ✓ = good fit; ~ = workable with compromises; ✗ = wrong choice.

Antenna class	Home base	Portable	Mobile	Handheld	Contest
Half-wave dipole	✓	✓	✗	✗	✓
Inverted V	✓	✓	✗	✗	✓
OCFD (Carolina Windom)	✓	~	✗	✗	✓
Fan dipole	✓	✗	✗	✗	✓
G5RV / ZS6BKW	✓	~	✗	✗	~
EFHW	✓	✓	~	✗	~
Full-size vertical (Hustler 6-BTV)	✓	~	✗	✗	✓
Mobile vertical (Hamstick)	~	✓	✓	✗	✗
Wolf River Coil / Buddistick	✗	✓	✗	✗	✗
J-pole / Slim Jim (rollup)	~	✓	✗	✗	~
Rubber duck / Slim-Duck	✗	~	~	✓	✗
Mobile NMO whip (2m/70cm)	✗	✗	✓	✗	~
Yagi (Mono-band)	✓	✗	✗	✗	✓
Yagi (Tri-band)	✓	✗	✗	✗	✓
Magnetic loop (TX, e.g. F-Loop)	✓	✓	✗	✗	~
Discone	✓	~	✗	✗	✓ (RX)
Log-periodic	✓	✗	✗	✗	✓
4-square vertical array	✓	✗	✗	✗	✓
Beverage (RX-only)	✓	✗	✗	✗	✓ (RX)
Active loop (Wellbrook)	✓	~	✗	✗	✓ (RX)
Stealth attic dipole	✓	✗	✗	✗	~
Flagpole-disguise vertical	✓	✗	✗	✗	~

16. A-Z glossary

Every defined term used across Vols 1-32. Each entry: one-or-two-sentence plain-language definition + the volume(s) where it’s treated in depth + related terms. Where a term appears in multiple volumes, the first reference is the authoritative one.

A

• A2C (Advantage Actor-Critic) — Reinforcement-learning algorithm used in PWNagotchi; mentioned in cross-reference but not antenna-related. PWNagotchi Vol 6.
• Adapter — A connector pair that converts between two connector families (PL-259-to-N, SMA-to-BNC, etc.). Each adapter adds 0.1-1.0 dB loss depending on frequency and quality. Vol 5 §9. See also: Connector.
• ADF4351 / ADF4355 — Analog Devices PLL synthesizer ICs commonly used in hobbyist signal generator boards (35 MHz – 4.4 GHz / 54 MHz – 6.8 GHz). Vol 26 §9. See also: Signal generator.
• Aperture (effective) — The cross-sectional area of incoming EM wave an antenna “captures.” A_eff = G·λ²/(4π). Vol 4 §8. See also: Effective area, Gain, Friis equation.
• Array (antenna) — Multiple antennas combined to shape a directional pattern via phasing. Vol 32. See also: Phased array, Stacking.
• Attenuation — Power loss per unit length of transmission line, expressed in dB/100 ft or dB/100 m. Vol 5 §5. See also: Coax, Loss.
• Autotransformer — A single-winding transformer where one section serves as both primary and secondary; used in 9:1 and 49:1 UNUNs. Vol 16 §4. See also: UNUN, Transmission-line transformer.
• Autotuner — An antenna tuner that automatically adjusts L/C values to minimize SWR. LDG / MFJ / mAT / Yaesu FC-30/40 representative models. Vol 17 §7. See also: Tuner, L-network.
• AWG (American Wire Gauge) — Standard wire-diameter sizing. AWG 14 = 1.628 mm; AWG 18 = 1.024 mm. Vol 6 §10. See also: Wire antenna.
• Azimuth pattern — Antenna radiation pattern in the horizontal plane (typically at the elevation of peak gain). Vol 4 §6. See also: Elevation pattern, HPBW.

B

• Balanced feedline — Two-conductor transmission line where both conductors carry equal-and-opposite current; ladder line, twin-lead, open-wire feeder. Vol 5 §7. See also: Coax, Common-mode current, Ladder line.
• BALUN — BALanced-to-UNbalanced transformer. Converts unbalanced coax to balanced antenna feedpoint, current-mode or voltage-mode. Vol 16. See also: UNUN, Choke, Common-mode current, Current BALUN, Voltage BALUN.
• Bandwidth — The frequency range over which an antenna meets a specified performance criterion (typically SWR < 2:1). Vol 4 §7. See also: Q, Resonance.
• Beam (antenna) — Casual term for a directional antenna; usually a Yagi or quad. Vol 11. See also: Directivity, Yagi-Uda.
• Beamwidth — Angular width of the main lobe between specified points; typically the 3 dB points. Vol 4 §6. See also: HPBW, FNBW.
• Beverage antenna — Long terminated wire antenna (typically 1-2 wavelengths) used for receive on low bands. Named for Harold Beverage (1922). Vol 15 §3. See also: Receive antenna, Termination.
• Bias-T — Network that combines DC and RF on a single coax for powering masthead amplifiers. Vol 18 §9. See also: Masthead preamp, Active distribution.
• Bifilar winding — Two parallel wires wound together on a core, used in current BALUNs. Vol 16 §11. See also: Trifilar, Quadrifilar, Ferrite.
• Bird 43 wattmeter — Through-line slug-based RF wattmeter; the de-facto laboratory reference (since 1952). Vol 26 §2. See also: Through-line wattmeter, Slug.
• BNC connector — Bayonet-coupling quick-disconnect 50/75 Ω connector; usable to ~4 GHz. Vol 5 §8. See also: Connector, TNC.
• Boom (Yagi) — The horizontal support tube that holds the parasitic elements of a Yagi. Longer boom → more gain (with diminishing returns). Vol 11 §4. See also: Director, Reflector, Driven element.

C

• Cage dipole — Dipole with multiple parallel conductors used as a single fat conductor for wideband performance. Vol 7 §9. See also: Bandwidth, Dipole.
• Cardioid pattern — Radiation pattern with one deep null and unidirectional peak gain. Vol 15 §11. See also: Pattern, Receive antenna.
• Carolina Windom — Off-center-fed dipole with vertical “radiator” section. Vol 7 §3. See also: OCFD, Multi-band dipole.
• Choke (RF) — A high-impedance device that blocks common-mode current on a feedline. Implemented as a 1:1 current BALUN. Vol 16 §5. See also: Common-mode current, BALUN.
• Coaxial cable (coax) — Transmission line with center conductor surrounded by dielectric and concentric shield. The standard 50 Ω amateur cable. Vol 5 §3, Vol 5 §4. See also: RG-58, LMR-400, Heliax.
• Common-mode current — Current that flows in the same direction on both conductors of a balanced line (or on the outside of a coax shield); the source of feedline radiation and RFI. Vol 5 §10. See also: Choke, Differential-mode current.
• Common-mode choke — See Choke (RF).
• Conjugate match — When source impedance equals the complex conjugate of load impedance; maximum power transfer. Vol 4 §3. See also: Impedance, Matching.
• Connector — Mechanical interface for joining transmission lines or attaching equipment. PL-259, BNC, N, SMA, TNC, RP-SMA are common. Vol 5 §8. See also: Adapter.
• Counterpoise — A wire or set of wires that serves as the “other half” of an antenna’s current loop (for EFHW, end-fed verticals, random wire). Vol 10 §7, Vol 20 §5. See also: Ground plane, Radial.
• Current BALUN — BALUN that forces equal-and-opposite currents on the two output terminals (vs voltage BALUN which forces equal-and-opposite voltages). Vol 16 §3. See also: Voltage BALUN, Guanella.
• Cushcraft — A US antenna manufacturer (now part of MFJ); known for the R-9 vertical and A50-5S 6m Yagi. Vol 8 §7.

D

• dB (decibel) — Logarithmic ratio of two power (or voltage) quantities. 1 dB ≈ 1.26×; 3 dB = 2×; 10 dB = 10×. Vol 3 §2. See also: dBm, dBW, dBi.
• dBd — Antenna gain referenced to a half-wave dipole. dBi = dBd + 2.15. Vol 3 §6. See also: dBi, Gain reference.
• dBi — Antenna gain referenced to an isotropic radiator. The most common modern reference. Vol 3 §6. See also: dBd, Isotropic.
• dBic — Antenna gain referenced to an isotropic circular-polarized radiator. Vol 3 §6. See also: dBi, Polarization.
• dBm — Absolute power expressed in decibels relative to 1 mW. 0 dBm = 1 mW; +30 dBm = 1 W. Vol 3 §4. See also: dBW.
• dBW — Absolute power relative to 1 W. dBW = dBm − 30. Vol 3 §4. See also: dBm.
• dBμV — Voltage expressed in decibels relative to 1 microvolt; common in EMC and receiver-sensitivity specs. Vol 3 §5. See also: dBμV/m.
• dBμV/m — Electric field strength in decibels relative to 1 microvolt per meter. Vol 3 §5. See also: Field strength.
• dBc — Power relative to a reference carrier; used for harmonic and intermodulation specifications. Vol 3 §5. See also: Harmonic, IMD.
• Differential-mode current — Current that flows in opposite directions on the two conductors of a feedline (the intended mode). Vol 5 §10. See also: Common-mode current.
• Diplexer — Frequency-domain splitter combining two bands into one antenna (e.g. 2m + 70cm). Vol 30 §5. See also: Multiplexer, Triplexer.
• Dipole (half-wave) — The canonical resonant wire antenna; λ/2 long, fed at center, ~70 Ω. Vol 6 §2. See also: Folded dipole, OCFD.
• Directivity — Ratio of an antenna’s peak radiation density to that of an isotropic radiator. Distinct from gain (which folds in losses). Vol 4 §5. See also: Gain, Efficiency.
• Director (Yagi) — A parasitic element placed in front of the driven element; shorter than the driven element. Vol 11 §3. See also: Driven element, Reflector.
• Discone — Wideband antenna consisting of a disc over a cone, named for Kandoian (1945). 10:1 bandwidth typical. Vol 12 §3. See also: Wideband, Sleeve antenna.
• Doublet — Dipole-class antenna fed with open-wire / ladder line, tuner-matched at the rig for all-band use. Vol 7 §6. See also: Ladder line, G5RV.
• Driven element — The element of a Yagi (or other array) that’s directly connected to the feedline. Vol 11 §3. See also: Director, Reflector.
• Dummy load — A 50 Ω non-radiating resistor used for transmitter testing. Sized for power dissipation. Vol 26 §4. See also: Dissipation, Cantenna.

E

• Effective area — See Aperture (effective).
• Efficiency — Ratio of power radiated to power delivered to the antenna terminals (η = R_rad / (R_rad + R_loss)). Vol 4 §5. See also: Radiation resistance, Ohmic resistance.
• EFHW (End-Fed Half-Wave) — Resonant wire antenna fed at the high-voltage end via a 49:1 UNUN. Vol 10 §4. See also: UNUN, Random wire.
• EIRP (Effective Isotropic Radiated Power) — TX power × antenna gain (in linear units); the equivalent power needed from an isotropic radiator to produce the same field strength in the main lobe. Vol 31 §7. See also: ERP, Friis equation.
• Elevated radial — A radial wire elevated above ground; typically λ/4 long, requires only 2-4 (vs 30+ for buried radials). Vol 20 §4. See also: Buried radial, Counterpoise.
• Elevation pattern — Antenna radiation pattern in the vertical plane (typically through the line of maximum gain). Vol 4 §6. See also: Azimuth pattern, Take-off angle.
• End-fed (antenna) — An antenna fed at one end rather than the center; EFHW or random wire are subclasses. Vol 10. See also: EFHW, Random wire.
• ERP (Effective Radiated Power) — TX power × antenna gain (linear units) referenced to a half-wave dipole. ERP = EIRP / 1.64 (or dBd vs dBi). Vol 31 §7. See also: EIRP.
• EWE antenna — Earl Cunningham’s short terminated-loop receive antenna (a “compressed Beverage”). Vol 15 §6. See also: Beverage, Receive antenna.
• EZNEC — Roy Lewallen (W7EL) NEC-2 / NEC-4 frontend; the de-facto amateur antenna-modeling reference. New sales retired 2024. Vol 28 §5. See also: NEC, 4nec2, Modeling.

F

• F/B (Front-to-back) ratio — Ratio of antenna gain in the forward direction to gain 180° behind. Vol 11 §5. See also: Yagi, Pattern.
• Fair-Rite — Major US ferrite-core manufacturer. Numbered mixes 31, 43, 52, 61, 67, 77, J, W are the amateur staples. Vol 16 §10. See also: Ferrite mix.
• Fan dipole — Multiple dipoles of different lengths fed from a single feedpoint for multi-band coverage. Vol 7 §4. See also: Multi-band dipole.
• Far field — The region beyond r = 2D²/λ where the antenna’s radiated pattern is fully developed. Vol 2 §6. See also: Near field, Fraunhofer distance.
• FDTD (Finite-Difference Time-Domain) — Numerical EM method that’s better than NEC for dielectric / PCB-substrate / finite-ground analysis. openEMS is the open-source implementation. Vol 28 §7. See also: Modeling, NEC.
• Feedline — The transmission line that connects radio to antenna. Coax, ladder line, hardline are the main classes. Vol 5. See also: Coax, Ladder line.
• Feedpoint — The point on an antenna where the feedline attaches; the impedance “seen” looking into the antenna. Vol 4 §3. See also: Impedance, Matching.
• Ferrite mix — A specific NiZn or MnZn composition used in cores; selected by frequency range and application. Vol 16 §10. See also: BALUN, Choke, NiZn, MnZn.
• Field strength — The electric field intensity at a point in space (V/m or dBμV/m). Vol 26 §10. See also: FSM, MPE.
• FNBW (First Null Beam Width) — Angular width between the first nulls on either side of the main lobe. Vol 4 §6. See also: HPBW, Pattern.
• Folded dipole — A dipole with the two halves connected as a loop at the ends; ~280 Ω feedpoint impedance. Vol 6 §6. See also: Dipole, 4:1 BALUN.
• 4nec2 — Free Windows frontend for the NEC-2/NEC-4 method-of-moments solver. Vol 28 §4. See also: NEC, EZNEC, Modeling.
• Fraunhofer distance — The distance beyond which the radiated field is in the far-field zone. ≈ 2D²/λ. Vol 2 §6. See also: Far field.
• Friis transmission equation — P_RX = P_TX · G_TX · G_RX · (λ/4πr)². Free-space link budget. Vol 2 §7. See also: Path loss, Link budget.

G

• Gain (antenna) — Antenna directivity multiplied by efficiency. G = D · η. Expressed in dBi or dBd. Vol 4 §5. See also: Directivity, Efficiency, dBi.
• Galvanic corrosion — Accelerated metal corrosion at junctions between dissimilar metals (e.g., aluminum + copper). Vol 22 §8. See also: Stainless, Aluminum.
• Gamma match — A capacitor-coupled feed for a 50 Ω coax onto a low-impedance Yagi driven element. Vol 11 §6. See also: Hairpin, T-match.
• Ground plane — A conductive surface or set of radials that serves as the “image” half of a monopole antenna. Vol 8 §6. See also: Counterpoise, Radial.
• Ground rod — A copper-clad steel rod driven into the earth for safety grounding; typically 8 ft × 5/8”. Vol 20 §9. See also: RF ground, NEC 250.
• Guanella — Gustav Guanella’s 1944 transmission-line transformer topology; the basis of modern current BALUNs. Vol 16 §7. See also: Ruthroff, Current BALUN.
• Guy wire — A tensioned cable that braces a mast or tower against horizontal forces. Vol 21 §6. See also: Mast, Tower.
• G5RV — Louis Varney’s 102-ft multi-band wire antenna with a 31-ft 450 Ω ladder-line matching section. Vol 7 §7. See also: ZS6BKW, Doublet, Multi-band dipole.

H

• Hairpin match — A shorted-stub inductive match used on Yagis with low-impedance driven elements. Vol 11 §6. See also: Gamma, T-match.
• Half-square — A 1/4-wave vertical with an additional 1/4-wave horizontal section, providing ~6 dB more gain than a quarter-wave alone. Vol 8 §9. See also: Vertical, Bobtail curtain.
• Halyard — A rope used to raise and lower an antenna or flag. Dacron, nylon, and Kevlar are the standard fibers. Vol 21 §10. See also: Mast, Pulley.
• Ham-stick — A short, loaded mobile HF whip antenna (~ 7 ft, single-band). Vol 9 §4. See also: Mobile, Loading.
• Heliax — Andrew/CommScope’s air-dielectric corrugated copper hardline coax. LDF4-50A (1/2”) and LDF5-50A (7/8”) are the amateur standards. Vol 5 §4. See also: Hardline, Coax.
• Hex beam — Six-element wire Yagi mounted on a spider-frame; popular for portable VHF/UHF and HF tribander work. Vol 14 §5. See also: Yagi, Wire antenna.
• Hi-Z 4-square — Hi-Z Antennas commercial 4-square receive array. Vol 32 §5. See also: 4-square, Receive array.
• HPBW (Half-Power Beam Width) — Angular width at the −3 dB points relative to peak gain. Vol 4 §6. See also: FNBW, Pattern.
• HOA — Homeowners Association; often restricts antennas through CC&Rs. PRB-1 protects amateur installations in some states but not all. Vol 23 §11. See also: Stealth, PRB-1.

I

• Impedance — The complex ratio of voltage to current at a point, in ohms. Z = R + jX. Vol 4 §3. See also: Reactance, Resistance, Matching.
• IMD (Intermodulation distortion) — Spurious signals generated when two or more frequencies mix in a nonlinear device. Vol 19 §11. See also: Linearity, Compression.
• Insertion loss — Power loss caused by inserting a component (filter, BALUN, splitter) into a signal path. Vol 18 §10. See also: Loss, Mismatch loss.
• Inverted-V dipole — A dipole hung from a single center support with the ends sloping down; cousin of the dipole with slightly different pattern. Vol 6 §6. See also: Dipole, Sloper.
• Isotropic radiator — Theoretical antenna radiating equal power in all directions; the reference for dBi. Vol 3 §6. See also: Dipole, dBi.
• ITU region — One of three global RF regulatory regions (1 = Europe/Africa/Russia; 2 = Americas; 3 = Asia-Pacific). Vol 31 §6. See also: FCC, Part 97.

J

• J-pole — End-fed half-wave VHF/UHF antenna with a 1/4-wave matching section; the “rollup roll-up.” Vol 9 §6. See also: Slim Jim, End-fed.

K

• K9AY loop — Gary Breed’s small receive-only terminated loop with directional null. Vol 15 §4. See also: Receive antenna, Termination.
• Kraken SDR — 5-channel coherent SDR for direction-finding via MUSIC or other DoA algorithms. Vol 32 §5. See also: MUSIC, Direction-finding.

L

• L-network — Two-element (one L + one C) impedance-matching network; the fundamental tuner topology. Vol 17 §3. See also: T-network, Pi-network, Tuner.
• Ladder line — Balanced two-conductor open-wire feedline; very low loss at HF. Vol 5 §7. See also: Open-wire, Balanced feedline.
• LDPA (Log-Periodic Dipole Array) — Wideband directional antenna with multiple dipoles of geometrically scaled lengths and spacings. Vol 13 §3. See also: Wideband, Yagi.
• LFA (Loop-Fed Array) — Justin Johnson G0KSC’s loop-fed Yagi topology; lower side-lobes and wider bandwidth than classic Yagi. Vol 11 §7. See also: Yagi, OWA.
• LMR-400 — Times Microwave 50 Ω low-loss coax; the modern HF-VHF-UHF default for runs >50 ft. Vol 5 §4. See also: Coax, LMR-600.
• Linked dipole — A dipole with link-insertable elements to swap bands manually. Vol 7 §8. See also: Multi-band dipole, Portable.
• Loop antenna (small magnetic, transmitting) — High-Q resonant loop, 1/10 to 1/4 wavelength circumference, capacitor-tuned. Magloop is the slang. Vol 14 §3. See also: Magloop, Q.
• Loss — Reduction in signal power due to dissipation (in cables, connectors, antennas, atmospheres). Expressed in dB. Vol 5 §5. See also: Attenuation, Mismatch loss.
• Loss tangent — A material property quantifying dielectric or magnetic loss. Lower is better for low-loss applications. Vol 16 §10. See also: Ferrite mix.

M

• Magloop — Slang for small magnetic transmitting loop antenna. Vol 14 §3. See also: Loop antenna.
• Mast — A pole used to elevate an antenna. Push-up steel, fiberglass, Spiderbeam HD, ham towers are the four common classes. Vol 21 §2. See also: Tower, Guy wire.
• Masthead preamp — RF amplifier mounted at the antenna to overcome coax loss on receive. Vol 19 §4. See also: LNA, Bias-T.
• Matching network — Network of L and C components that transforms one impedance to another. Vol 17. See also: L-network, BALUN, Tuner.
• Method of moments (MoM) — Numerical EM technique that solves antenna currents on segmented wires; the basis of NEC. Vol 28 §3. See also: NEC, FDTD, Modeling.
• MFJ — MFJ Enterprises, a US ham-radio equipment manufacturer (1972-2023). Known for antenna analyzers, tuners, and other amateur gear. Vol 25 §4. See also: Analyzer, Tuner.
• Mismatch loss — Power not delivered to the load due to impedance mismatch; ML = −10·log(1 − |Γ|²). Vol 3 §8. See also: SWR, Return loss.
• MMANA-GAL — Free NEC-derived antenna modeler (Goncharenko / JA1WBX / Schewelew). Vol 28 §6. See also: NEC, Modeling.
• Monopole — Quarter-wave vertical antenna over a ground plane (image plane). Vol 8 §2. See also: Vertical, Ground plane.
• MPE (Maximum Permissible Exposure) — FCC regulatory limit on RF exposure to humans; specified in mW/cm² as a function of frequency. Vol 31 §8. See also: OET-65, RF safety.
• MUSIC algorithm — Multiple Signal Classification — DoA algorithm for direction-finding with phased arrays. Vol 32 §5. See also: Direction-finding, Kraken SDR.

N

• N connector — Threaded 50 Ω connector, usable to 11 GHz, weatherproof when properly torqued; the outdoor amateur standard. Vol 5 §8. See also: Connector, SMA.
• NanoVNA — Low-cost 2-port vector network analyzer (typically $60-$300). Vol 24. See also: VNA, S-parameters.
• Near field — The region within r = 2D²/λ where the antenna’s E and H fields are still developing. Vol 2 §6. See also: Far field, Fraunhofer distance.
• NEC (Numerical Electromagnetic Code) — Method-of-moments antenna modeling code developed at LLNL. NEC-2 is open; NEC-4 requires LLNL license. Vol 28 §3. See also: 4nec2, EZNEC, MMANA-GAL.
• NEC 250 — National Electrical Code Article 250 (grounding and bonding for AC distribution); applies to antenna installations. Vol 20 §6. See also: NEC 810, Ground rod.
• NEC 810 — National Electrical Code Article 810 (radio and TV antenna installations). Vol 20 §6. See also: NEC 250.
• NiZn — Nickel-Zinc ferrite material — the workhorse for amateur RF chokes and transformers. Vol 16 §10. See also: Ferrite mix, MnZn.
• NMO mount — Motorola-style threaded mobile antenna mount. Vol 9 §3. See also: Mobile, Mag-mount.
• NVIS — Near Vertical Incidence Skywave; HF propagation mode using high-angle radiation for ~50-500 km coverage. Vol 2 §4. See also: Propagation, Sky wave.

O

• OCFD (Off-Center-Fed Dipole) — Multi-band dipole with the feedpoint ~14% off-center; matched via 4:1 BALUN. Vol 7 §3. See also: Carolina Windom, Multi-band dipole.
• OET-65 (Bulletin) — FCC Office of Engineering and Technology Bulletin 65; the workflow document for amateur MPE compliance. Vol 31 §9. See also: MPE, RF safety.
• Ohmic resistance — Resistance due to conductor losses (skin effect, finite conductivity). Vol 4 §5. See also: Radiation resistance, Efficiency.
• OpenEMS — Open-source FDTD electromagnetic simulator. Vol 28 §7. See also: FDTD, Modeling.
• Open-wire feeder — Balanced parallel-wire transmission line with air dielectric. Vol 5 §7. See also: Ladder line.
• OSL calibration — Open / Short / Load standards used to calibrate a VNA. Vol 24 §5. See also: SOLT, NanoVNA.
• OWA (Optimized Wideband Antenna) — A Yagi design optimized for wideband performance with constant element-to-boom relationships. Vol 11 §7. See also: Yagi, LFA.

P

• Parasitic element — Antenna element not directly connected to the feedline (e.g., Yagi director, reflector). Vol 11 §3. See also: Driven element, Yagi.
• Patch antenna — A planar resonant antenna on dielectric substrate, common at GHz frequencies. Vol 13 §5. See also: Microstrip, Vivaldi.
• Phased array — Multiple antennas with controlled phase relationships to produce beam-shape or beam-steering. Vol 32 §5. See also: 4-square, Stacking.
• Pi-network — Three-element matching network (C-L-C); used in high-Q amplifier matching. Vol 17 §5. See also: L-network, T-network.
• PIN diode — RF-current-controlled switching diode; used in RF switching matrices. Vol 30 §11. See also: Switching matrix, RF switch.
• PL-259 — UHF-series threaded connector, 1930s legacy design, impedance-discontinuous; the de-facto HF amateur connector. Vol 5 §8. See also: SO-239, Connector.
• Polarization — Orientation of the electric field of an EM wave (vertical, horizontal, circular, elliptical). Vol 2 §5. See also: Cross-pol, Circular polarization.
• Polyphaser — A coaxial lightning arrestor (the company and the generic name). Vol 20 §8. See also: Lightning, Arrestor.
• PRB-1 — FCC PRB-1 ruling (1985) — limited preemption of state and local antenna restrictions for amateurs. Vol 23 §11. See also: HOA, Antenna parity act.
• Propagation — How RF travels from antenna to antenna (ground wave, sky wave, line-of-sight, NVIS, sporadic-E, tropo, etc.). Vol 2 §4.
• Push-up mast — Telescoping steel or aluminum mast that extends section-by-section. Vol 21 §3. See also: Fiberglass mast, Mast.

Q

• Q (quality factor) — Antenna or resonant circuit selectivity; high-Q = narrow bandwidth, low-Q = wide bandwidth. Vol 4 §7. See also: Bandwidth, Resonance.
• Quad antenna — A full-wave loop antenna, often square or diamond. The cubical quad is a Yagi-like array of full-wave loops. Vol 14 §4. See also: Loop antenna, Hex beam.
• Quadrature hybrid — 90° power-divider with 3 dB equal split and 90° phase difference between outputs. Vol 18 §5. See also: Wilkinson, Hybrid coupler.

R

• Radial — A wire run on or above ground, forming the “other half” of a monopole’s current path. Vol 20 §4. See also: Counterpoise, Ground plane.
• Radiation pattern — 3D directional plot of an antenna’s radiated power density. Vol 4 §6. See also: Azimuth, Elevation, HPBW.
• Radiation resistance — The “fictitious” resistance that, if multiplied by I², equals the radiated power. Vol 4 §5. See also: Ohmic resistance, Efficiency.
• Random wire — Non-resonant wire antenna of arbitrary length, fed against a counterpoise via a 9:1 UNUN + tuner. Vol 10 §3. See also: EFHW, Long-wire.
• RBW (Resolution Bandwidth) — Spectrum analyzer filter bandwidth — narrower means more sensitivity but slower sweep. Vol 27 §2. See also: VBW, Spectrum analyzer.
• Reactance (X) — Imaginary part of impedance (Z = R + jX); inductive (+jX) or capacitive (−jX). Vol 4 §3. See also: Impedance, Resonance.
• Receive antenna — An antenna optimized for reception, typically prioritizing SNR over efficiency. Beverage, K9AY, EWE are classic examples. Vol 15. See also: Beverage, K9AY.
• Reciprocity — Antenna patterns are identical for TX and RX in a linear medium. Vol 4 §9. See also: Pattern, S-parameters.
• Reflection coefficient (Γ) — Ratio of reflected to incident voltage wave at a load. |Γ| relates directly to SWR and return loss. Vol 4 §4. See also: SWR, Smith chart.
• Reflector (Yagi) — Parasitic element behind the driven element; longer than the driven element. Vol 11 §3. See also: Director, Yagi.
• Resonance — Frequency at which the antenna’s reactance is zero (purely resistive feedpoint). Vol 4 §3. See also: Impedance, Tuning.
• Return loss (RL) — How much of the forward power is reflected, expressed in positive dB. RL = −20·log|Γ|. Vol 3 §8. See also: SWR, Mismatch loss.
• RF ground — A grounding system optimized for RF currents (vs DC or safety ground). Vol 20 §2. See also: Counterpoise, Single-point ground.
• RFI (Radio Frequency Interference) — Unwanted RF energy coupling into receivers, audio gear, or sensitive electronics. Vol 5 §10. See also: Common-mode, TVI.
• RG-58 / RG-58A — Mil-spec 50 Ω flexible coax, ~5 mm OD, used for short low-power runs. Vol 5 §4. See also: Coax, RG-213.
• RG-213 — Mil-spec 50 Ω flexible coax, ~10 mm OD, the “thick” HF/VHF coax. Vol 5 §4. See also: Coax.
• RigExpert — Ukrainian-American manufacturer of amateur antenna analyzers (AA-Stick Pro through AA-2000 Zoom). Vol 25 §3. See also: Analyzer.
• Rohn — Major US tower manufacturer (25G, 45G, 55G, 65G are common amateur towers). Vol 21 §5. See also: Tower.
• RP-SMA (Reverse-Polarity SMA) — Mechanically identical to SMA but with the center conductor / socket polarity reversed. The consumer Wi-Fi standard. Vol 5 §8. See also: SMA, Connector.
• Ruthroff — 1959 Charles Ruthroff transmission-line transformer topology; the basis of voltage BALUNs. Vol 16 §7. See also: Guanella, Voltage BALUN.

S

• S-parameters — Scattering parameters (S11, S21, S12, S22); characterize an N-port linear network. Vol 24 §2. See also: VNA, Reflection coefficient.
• S11 — Reflection coefficient at port 1 of a 2-port network. Vol 24 §7. See also: Return loss, SWR.
• S21 — Transmission coefficient from port 1 to port 2 (forward gain). Vol 24 §8. See also: Gain, Insertion loss.
• Salt-spray test — Standardized corrosion test simulating coastal environments. Vol 22 §10. See also: Corrosion, Coastal install.
• Self-amalgamating tape — Silicone rubber tape that bonds to itself when stretched; the canonical coax weatherproofing. Vol 22 §4. See also: Weatherproofing, Coax-Seal.
• SGC-237 (Coupler) — Mast-base autotuner from SGC; remote-mount for end-fed wire antennas. Vol 17 §9. See also: Autotuner, Remote tuner.
• Signal generator — RF source for testing receivers and characterizing antennas. Vol 26 §6. See also: ADF4351, Tracking generator.
• Skin depth — The depth at which RF current density falls to 1/e of surface value; ~9 mm at 60 Hz, ~17 µm at 14 MHz in copper. Vol 5 §3. See also: Conductor loss.
• Sleeve antenna — Half a discone over a ground plane; wideband vertical for VHF/UHF. Vol 12 §4. See also: Discone, Wideband.
• Slim Jim — End-fed half-wave VHF antenna with a folded matching section. Vol 9 §6. See also: J-pole, End-fed.
• Sloper — A dipole or vertical with one end higher than the other. Vol 6 §6, Vol 10 §6. See also: Inverted-V, Dipole.
• Smith chart — Polar plot of complex reflection coefficient; the canonical impedance-matching visualization tool. Vol 4 §4, Vol 17 §6. See also: Impedance, Matching.
• SMA connector — Threaded subminiature 50 Ω connector, usable to 18 GHz; the test-bench and small-form standard. Vol 5 §8. See also: RP-SMA, Connector.
• SO-239 — The female chassis-mount mate of PL-259. Vol 5 §8. See also: PL-259, Connector.
• Sommerfeld real-ground model — NEC-2 / NEC-4 ground model that accounts for finite ground conductivity and permittivity. Vol 28 §9. See also: NEC, Ground model.
• Spectrum analyzer (SA) — Instrument that displays signal power vs frequency. Vol 27. See also: TinySA, Signal Hound.
• Splitter — Passive RF device that divides input power among multiple outputs; resistive, Wilkinson, or hybrid topologies. Vol 18. See also: Combiner, Wilkinson.
• Spiderbeam — German manufacturer of fiberglass masts and Yagi kits. Vol 21 §4. See also: Fiberglass mast, Hex beam.
• Stacking — Combining multiple Yagis (vertically or horizontally) for additional gain. Vol 32 §3. See also: Phasing, 4-square.
• Stealth antenna — Antenna designed to be visually inconspicuous; for HOA / restricted-space applications. Vol 23. See also: PRB-1, Attic, Flagpole.
• SWR (Standing Wave Ratio) — Ratio of maximum to minimum voltage on a transmission line with mismatched load. SWR = (1 + |Γ|) / (1 − |Γ|). Vol 3 §8. See also: Return loss, Reflection coefficient.

T

• Take-off angle — The elevation angle of peak radiation; lower = better DX, higher = better NVIS / short-distance. Vol 8 §4. See also: Elevation pattern, Vertical.
• T-match — Three-conductor coaxial-impedance match for Yagi driven elements. Vol 11 §6. See also: Gamma, Hairpin.
• T-network — Three-element tuner topology (C-L-C series-shunt-series); the classic transmatch. Vol 17 §4. See also: L-network, Pi-network, Transmatch.
• TDR (Time-Domain Reflectometry) — Pulse-based method for finding cable faults via reflection timing. Vol 24 §10. See also: NanoVNA, S11.
• Tektronix RSA306 — USB-controlled real-time spectrum analyzer with 40 MHz bandwidth. Vol 27 §5. See also: Real-time SA, Spectrum analyzer.
• TinySA — Pocket spectrum analyzer (original 100 kHz – 350 MHz; Ultra to 5.3 GHz). Vol 27 §3. See also: Spectrum analyzer.
• TLT (Transmission-Line Transformer) — Transformer where the windings act as a transmission line; the basis of current BALUNs. Vol 16 §4. See also: Guanella, Current BALUN.
• TNC connector — Threaded version of BNC; usable to 11 GHz, better vibration resistance. Vol 5 §8. See also: BNC, Connector.
• Tower — A vertical structural framework for mounting antennas. Rohn 25G/45G/55G/65G, US Towers MA-40/770MDP are common. Vol 21 §5. See also: Mast, Guy wire.
• Tracking generator — A signal source synchronized with a spectrum analyzer’s sweep for filter / SWR measurement. Vol 27 §9. See also: Spectrum analyzer, NanoVNA.
• Transmission line — A controlled-impedance pair of conductors carrying RF (coax, ladder line, microstrip). Vol 5 §2. See also: Coax, Ladder line.
• Trap (in antenna) — A parallel LC circuit inserted in a wire antenna to electrically shorten it at higher frequencies. Vol 7 §5. See also: Trap dipole, Multi-band.
• Trifilar winding — Three parallel wires wound together on a core, used in 9:1 UNUNs. Vol 16 §11. See also: Bifilar, UNUN.
• Trim (antenna) — Adjust antenna length or matching components to move resonance. Vol 6 §10. See also: Resonance, SWR.
• Tuner (antenna) — Variable LC matching network that transforms antenna impedance to 50 Ω at the rig. Vol 17. See also: Autotuner, L-network.
• TVI (TV Interference) — Interference to broadcast TV from an amateur transmitter. Vol 5 §10, Vol 31 §11. See also: RFI, Common-mode.

U

• UHF connector — See PL-259.
• UNUN (UNbalanced-to-UNbalanced) — Impedance transformer that doesn’t convert balance state; used for end-fed antennas. 9:1, 49:1, 64:1 are common. Vol 16 §8, Vol 16 §9. See also: BALUN, Autotransformer.
• Ufer ground — A ground rod or wire embedded in the concrete foundation; named for Herbert Ufer. Vol 20 §9. See also: Ground rod.
• US Towers — US-made motorized crank-up towers (MA-40, MA-770MDP). Vol 21 §5. See also: Tower, Rohn.

V

• VBW (Video Bandwidth) — Spectrum analyzer’s post-detector filter — narrower averages out noise but slows sweep. Vol 27 §2. See also: RBW.
• Velocity factor (VF) — Ratio of signal propagation speed in a transmission line to c. RG-58: 0.66; LMR-400: 0.85. Vol 5 §6. See also: Coax, Wavelength.
• VNA (Vector Network Analyzer) — Instrument that measures complex S-parameters of an N-port linear network. Vol 24. See also: NanoVNA, S-parameters.
• Voltage BALUN — BALUN that enforces equal-and-opposite voltages on the output terminals; less common than current BALUNs in modern amateur work. Vol 16 §3. See also: Current BALUN, Guanella, Ruthroff.
• VSWR — See SWR.

W

• W2DU choke — Walter Maxwell’s W2DU bead-string common-mode choke, made by sliding ~50 ferrite beads over RG-303 or similar small-diameter coax. Vol 16 §17. See also: Choke, Ferrite bead.
• Wavelength (λ) — Distance between successive crests of a wave; λ = c / f. Vol 2 §2. See also: Frequency, Velocity factor.
• Wattmeter — Instrument measuring RF power, typically through-line type. Vol 26 §2. See also: Bird 43, Cross-needle.
• Wilkinson splitter — Equal-split power divider with port isolation; the workhorse RF splitter. Vol 18 §4. See also: Splitter, Quadrature hybrid.
• Window line — Plastic-insulated balanced feedline with slotted “windows” for impedance control; less expensive than open ladder line. Vol 5 §7. See also: Ladder line, Twin-lead.
• Wolf River Coil — Compact loaded vertical (Buddistick-style) with quick-disconnect bands. Vol 9 §5. See also: Portable HF, Loading.
• Wow factor — When you build a 20m dipole, hoist it 30 ft up, and on your first call hear a station from Croatia answer in 73 seconds. Vol 6 §10.

Y

• Yagi-Uda antenna — Directional array invented by Hidetsugu Yagi and Shintaro Uda (1926). Driven element + reflector + 1-N directors. Vol 11 §2. See also: Driven element, Director, Reflector, LFA, OWA.

Z

• Z₀ (characteristic impedance) — The impedance of an infinite section of transmission line, set by geometry and materials. 50 Ω standard; 75 Ω for video; 600 Ω for ladder line. Vol 5 §3. See also: Coax, Ladder line.
• ZS6BKW — A 92-foot variant of the G5RV with better multi-band SWR; from Brian Austin ZS6BKW. Vol 7 §7. See also: G5RV, Multi-band dipole.

17. Canonical anchor index for inbound cross-deep-dive links

Frozen H2 anchors across Vols 1-32 — the stable cross-deep-dive link surface. Anchor names follow the auto-generated convention vol{NN}-<heading-slug> (lowercase, hyphenated, leading section numbers stripped). Other Hack Tools deep dives (especially Hacker Tradecraft Vols 13-15) and external references should link to these anchors rather than authoring new ones.

Grouped by volume. Within each volume, listed in document order, with the canonical (most-likely-linked) anchors selected — not every H2.

Vol 1 — Overview

Anchor	Topic
vol01-the-32-volume-map-at-a-glance	32-volume map
vol01-the-antenna-decision-graph	Decision graph
vol01-the-per-antenna-template-diy-buy-side-by-side	Per-antenna template
vol01-wavelength-band-posture-the-three-questions-every-chapter-answers	The three questions

Vol 2 — RF fundamentals

Anchor	Topic
vol02-wavelength-frequency-and-the-speed-of-light	Wavelength and frequency
vol02-propagation-modes-ground-wave-sky-wave-line-of-sight-nvis	Propagation modes
vol02-polarization-linear-circular-slant-and-why-it-matters	Polarization
vol02-near-field-far-field-and-the-fraunhofer-distance	Near/far field
vol02-the-friis-transmission-equation-and-free-space-path-loss	Friis equation

Vol 3 — dB and dBm

Anchor	Topic
vol03-what-a-decibel-is-and-why-we-use-one	What a decibel is
vol03-power-db-vs-voltage-db-the-factor-of-two-trap	Power dB vs voltage dB
vol03-dbm-and-dbw-absolute-power-references	dBm and dBW
vol03-d-b-v-d-b-v-m-d-bc-the-niche-references-that-show-up-in-scopes-emc-and-harmonics	dBμV, dBμV/m, dBc
vol03-gain-references-dbi-vs-dbd-vs-dbic-vs-dbq	Gain references
vol03-mental-math-shortcuts-3-10-3-10-and-the-db-to-ratio-cheat-table	Mental-math shortcuts
vol03-return-loss-mismatch-loss-and-swr-three-views-of-the-same-problem	Return loss / mismatch loss / SWR
vol03-link-budgets-worked-examples	Link budgets
vol03-the-most-common-db-mistakes-a-triage-list	Common dB mistakes

Vol 4 — Antenna theory

Anchor	Topic
vol04-antenna-as-a-transformer-between-guided-and-free-space-waves	Antenna as transformer
vol04-feedpoint-impedance-and-resonance	Feedpoint impedance
vol04-swr-reflection-coefficient-and-the-smith-chart	SWR / reflection coefficient / Smith chart
vol04-gain-directivity-and-efficiency-the-three-numbers-and-how-they-relate	Gain / directivity / efficiency
vol04-radiation-patterns-azimuth-elevation-beamwidth-hpbw-front-to-back	Radiation patterns
vol04-bandwidth-and-q-why-high-gain-narrow-band-antennas-are-a-thing	Bandwidth and Q
vol04-aperture-effective-area-and-the-receive-side-picture	Aperture and effective area
vol04-reciprocity-when-tx-antenna-rx-antenna-and-when-it-doesnt	Reciprocity

Vol 5 — Transmission lines

Anchor	Topic
vol05-what-a-transmission-line-does-impedance-propagation-loss	What a transmission line does
vol05-coaxial-cable-geometry-materials-characteristic-impedance	Coax geometry
vol05-the-coax-catalogue-rg-58-rg-8x-lmr-240-lmr-400-lmr-600-rg-213-hardline	Coax catalogue
vol05-loss-per-100-ft-per-band-the-canonical-table	Loss per 100 ft
vol05-velocity-factor-and-length-critical-applications	Velocity factor
vol05-ladder-line-open-wire-twin-lead-when-balanced-feedline-wins	Ladder line
vol05-connectors-sma-n-bnc-tnc-uhf-f-rp-sma-the-maximum-frequency-of-each	Connectors
vol05-adapters-the-loss-budget-of-a-no-loss-adapter	Adapter loss budget
vol05-common-mode-currents-feedline-radiation-and-the-case-for-a-choke-balun	Common-mode currents

Vol 6 — Single-band dipoles

Anchor	Topic
vol06-geometry-theory-of-operation-the-half-wave-dipole	Half-wave dipole theory
vol06-feedpoint-impedance-and-matching	Feedpoint impedance
vol06-radiation-pattern-azimuth-elevation-polarization	Radiation pattern
vol06-frequency-response-swr-curve	SWR curve
vol06-variants-folded-inverted-v-sloper-vertical-dipole	Variants
vol06-diy-build-a-40-m-half-wave-dipole-step-by-step	DIY 40m dipole

Vol 7 — Multi-band dipoles

Anchor	Topic
vol07-off-center-fed-dipole-ocfd-carolina-windom	OCFD
vol07-fan-dipole-parallel-resonators-on-one-feedpoint	Fan dipole
vol07-trap-dipole-lc-traps-for-band-by-band-resonance	Trap dipole
vol07-doublet-open-wire-fed-tuner-fed-all-band	Doublet
vol07-g5rv-and-zs6bkw-the-102-foot-solutions	G5RV / ZS6BKW
vol07-linked-dipole-manual-band-swap-by-inserting-links	Linked dipole

Vol 8 — Fixed verticals

Anchor	Topic
vol08-geometry-theory-the-quarter-wave-monopole-over-ground	Quarter-wave monopole
vol08-radiation-pattern-the-low-angle-vertical-advantage	Low-angle pattern
vol08-ground-plane-vs-elevated-radials-efficiency-tradeoff	Ground plane vs elevated
vol08-full-size-hf-trap-verticals-hustler-4-btv-5-btv-6-btv-cushcraft-r-9-gap-titan	Trap verticals
vol08-shortened-loaded-verticals-coil-cap-hat-loading-and-the-efficiency-penalty	Shortened verticals
vol08-the-half-square-a-1-4-wave-vertical-with-6-db-more-gain	Half-square

Vol 9 — Portable & mobile monopoles

Anchor	Topic
vol09-mobile-mag-mount-and-nmo-whips-vhf-uhf-on-a-vehicle	Mobile mag-mounts
vol09-ham-stick-mobile-hf-whips	Ham-sticks
vol09-portable-hf-mp-1-ax-1-buddistick-wolf-river-coil	Portable HF
vol09-j-pole-slim-jim-and-the-end-fed-half-wave-vhf-uhf-case	J-pole / Slim Jim
vol09-rubber-ducks-and-helical-antennas-the-compromise-antenna	Rubber ducks
vol09-telescoping-whips-for-sdr-receive	SDR telescoping whips

Vol 10 — Random wire & end-fed

Anchor	Topic
vol10-random-wire-non-resonant-length-9-1-unun-tuner	Random wire
vol10-end-fed-half-wave-efhw-resonant-length-49-1-64-1-unun	EFHW
vol10-long-wire-multiple-wavelength-designs	Long wire
vol10-sloper-and-inverted-l-geometric-variants	Sloper / inverted-L
vol10-feedpoint-impedance-unun-selection-counterpoise-length	Counterpoise
vol10-diy-build-a-40-ft-efhw-for-40-20-15-10-m	DIY EFHW

Vol 11 — Yagi-Uda

Anchor	Topic
vol11-geometry-theory-the-parasitic-array-principle	Parasitic-array principle
vol11-the-three-element-types-driven-reflector-director	Three element types
vol11-boom-length-vs-gain-the-diminishing-returns-curve	Boom length vs gain
vol11-front-to-back-ratio-and-side-lobe-suppression	F/B ratio
vol11-feedpoint-impedance-and-matching-direct-gamma-hairpin-t-match-lfa-loop	Feedpoint matching
vol11-single-band-vs-lfa-vs-owa-topologies	Single-band vs LFA vs OWA
vol11-radiation-pattern-azimuth-elevation-hpbw	Radiation pattern

Vol 12 — Discone family

Anchor	Topic
vol12-geometry-theory-why-a-cone-over-a-disc-is-wideband	Discone theory
vol12-the-discone-proper-kandoians-original-geometry	Discone proper
vol12-the-sleeve-antenna-half-a-discone-over-a-ground-plane	Sleeve antenna
vol12-biconical-and-conical-monopole-the-emc-test-variants	Biconical / conical
vol12-radiation-pattern-omnidirectional-with-low-angle-null	Discone pattern
vol12-frequency-response-the-10-1-bandwidth-claim-examined	10:1 bandwidth

Vol 13 — Log-periodic & structured wideband

Anchor	Topic
vol13-geometry-theory-frequency-independence-by-self-similarity	Frequency-independence
vol13-the-lpda-log-periodic-dipole-array	LPDA
vol13-the-horn-antenna-for-microwave-gain	Horn antenna
vol13-the-spiral-and-equiangular-spiral	Spiral
vol13-the-vivaldi-tapered-slot-wideband-antenna	Vivaldi

Vol 14 — Transmitting loops

Anchor	Topic
vol14-geometry-theory-magnetic-vs-electric-loop-radiators	Magnetic vs electric loops
vol14-small-magnetic-transmitting-loops-the-high-q-narrow-bandwidth-case	Small magnetic transmitting loops
vol14-full-wave-loops-delta-quad-square	Full-wave loops
vol14-the-hex-beam-six-element-wire-yagi-on-a-spider	Hex beam
vol14-feedpoint-impedance-and-matching-capacitor-tuning	Capacitor tuning
vol14-power-handling-capacitor-voltage-the-5-kv-consideration	Capacitor voltage

Vol 15 — Receive-only loops & specialty

Anchor	Topic
vol15-geometry-theory-antennas-optimized-for-snr	SNR-optimized antennas
vol15-the-beverage-long-terminated-wire-the-king-of-low-band-receive	Beverage
vol15-the-k9ay-loop-small-terminated-loop-with-directional-null	K9AY loop
vol15-flag-and-pennant-terminated-loops-in-small-footprints	Flag / pennant
vol15-ewe-earl-cunninghams-truncated-beverage	EWE
vol15-ferrite-rod-loopstick-the-am-radio-antenna	Ferrite rod / loopstick
vol15-active-receive-loops-wellbrook-ala1530-lz1aq-bonito-megaloop	Active receive loops

Vol 16 — BALUNs and UNUNs

Anchor	Topic
vol16-what-a-balun-does-and-what-a-unun-does	BALUN vs UNUN
vol16-current-vs-voltage-baluns	Current vs voltage
vol16-transmission-line-vs-autotransformer-topologies	TL vs autotransformer
vol16-the-1-1-current-balun-the-default-feedpoint-choke	1:1 current BALUN
vol16-the-4-1-current-balun-for-ocfd-folded-dipole-doublet	4:1 current BALUN
vol16-the-4-1-voltage-balun-guanella-vs-ruthroff	4:1 voltage BALUN
vol16-the-9-1-unun-for-random-wire-non-resonant-feed	9:1 UNUN
vol16-the-49-1-and-64-1-unun-for-efhw	49:1 / 64:1 UNUN
vol16-ferrite-mix-selection-43-31-61-52-67	Ferrite mix selection
vol16-bifilar-trifilar-quadrifilar-winding-methods	Winding methods
vol16-power-handling-and-saturation	Power handling
vol16-common-mode-choke-line-isolator-recipes	Common-mode choke
vol16-testing-baluns-and-ununs-with-a-nanovna	NanoVNA testing

Vol 17 — Antenna tuners

Anchor	Topic
vol17-what-a-tuner-does-and-what-it-doesnt	What a tuner does
vol17-l-network-the-fundamental-two-element-match	L-network
vol17-t-network-the-classic-three-element-transmatch	T-network
vol17-pi-network-for-high-q-matches	Pi-network
vol17-smith-chart-matching-by-hand	Smith-chart matching
vol17-autotuners-ldg-mfj-mat-icom-at-180-yaesu-fc-30-40	Autotuners
vol17-balanced-tuners-for-ladder-line-doublet	Balanced tuners

Vol 18 — Passive splitters & couplers

Anchor	Topic
vol18-splitter-vs-combiner-vs-coupler-what-each-is-for	Splitter / combiner / coupler
vol18-resistive-splitter-the-simplest-most-lossy-option	Resistive splitter
vol18-wilkinson-equal-split-with-isolation	Wilkinson
vol18-quadrature-hybrid-90-hybrid-the-3-db-90-workhorse	Quadrature hybrid
vol18-rat-race-180-hybrid	Rat-race / 180° hybrid
vol18-directional-couplers-for-swr-return-loss-measurement	Directional couplers
vol18-bias-t-splitting-rf-from-dc-for-masthead-amplifiers	Bias-T

Vol 19 — Active splitters & preamps

Anchor	Topic
vol19-when-passive-isnt-enough-the-link-budget-case-for-active-distribution	Active distribution case
vol19-mmic-lnas-the-front-end-gain-block	MMIC LNAs
vol19-masthead-preamps-rx-gain-at-the-antenna	Masthead preamps
vol19-active-distribution-amplifiers-one-antenna-many-receivers	Active distribution amps
vol19-noise-figure-budget-friis-cascade	Noise figure budget
vol19-t-r-switching-protecting-lnas-during-tx	T/R switching

Vol 20 — Grounding

Anchor	Topic
vol20-three-different-grounds-and-why-confusing-them-gets-people-killed	Three grounds
vol20-rf-ground-the-image-plane-for-verticals	RF ground
vol20-radial-fields-buried-vs-elevated	Radial fields
vol20-counterpoise-for-end-fed-and-random-wire-antennas	Counterpoise
vol20-safety-ac-ground-bond	Safety / AC ground bond
vol20-lightning-protection-single-point-ground-architecture	Lightning protection
vol20-polyphaser-and-other-lightning-arrestors	Lightning arrestors
vol20-ground-rods-ground-rings-ufer-butt-ground-chemical-grounds	Ground rods

Vol 21 — Mounting / masts / ropes

Anchor	Topic
vol21-mast-classes-telescoping-fiberglass-spiderbeam-ham-tower	Mast classes
vol21-telescoping-push-up-masts	Push-up masts
vol21-fiberglass-poles-spiderbeam-mfj-dx-engineering	Fiberglass poles
vol21-ham-towers-rohn-25-45-55-65-us-towers	Ham towers
vol21-guy-wire-geometry-tension-and-dampers	Guy wires
vol21-line-throwing-air-cannon-slingshot-bow-arrow-drone	Line-throwing
vol21-halyards-dacron-vs-nylon-vs-kevlar	Halyards
vol21-climbing-safety-the-only-really-dangerous-part-of-this-hobby	Climbing safety

Vol 22 — Weatherproofing

Anchor	Topic
vol22-the-four-enemies-water-uv-ice-corrosion	Four enemies
vol22-sealing-connectors-the-canonical-sandwich	Sealing sandwich
vol22-coax-seal-vs-self-amalgamating-tape-vs-3m-scotchkote	Sealant comparison
vol22-uv-rated-insulators-and-dielectrics	UV-rated insulators
vol22-stainless-steel-hardware-when-and-where	Stainless hardware
vol22-galvanic-corrosion-dissimilar-metal-contacts	Galvanic corrosion
vol22-lightning-damage-assessment-after-a-strike	Lightning damage

Vol 23 — Stealth & restricted-space

Anchor	Topic
vol23-the-constrained-posture-problem	Constrained posture
vol23-attic-antennas-full-size-with-no-view-from-the-street	Attic antennas
vol23-mag-loop-in-a-closet-or-balcony	Closet magloop
vol23-flagpole-disguise-antennas	Flagpole antennas
vol23-gutter-as-antenna-and-its-discontents	Gutter as antenna
vol23-window-mount-antennas	Window-mount
vol23-legal-when-hoas-can-and-cant-restrict	HOA legal

Vol 24 — NanoVNA

Anchor	Topic
vol24-what-a-vna-does-the-2-port-s-parameter-primer	S-parameter primer
vol24-nanovna-hardware-history-v2-saa-2n-hugen-v3-litevna-nanovna-f	NanoVNA hardware history
vol24-calibration-osl-open-short-load-and-through	OSL calibration
vol24-calibration-kits-quality-matters	Calibration kits
vol24-s11-measurement-return-loss-swr-impedance	S11 measurement
vol24-s21-measurement-gain-loss-filter-response	S21 measurement
vol24-smith-chart-workflow-on-the-device	Smith-chart workflow
vol24-time-domain-reflectometry-finding-faults	TDR
vol24-nanovna-saver-and-other-host-software	NanoVNA-Saver
vol24-measuring-an-antenna-in-the-field-the-deployment-day-workflow	Deployment-day workflow

Vol 25 — Other VNAs

Anchor	Topic
vol25-antenna-analyzer-vs-vna-whats-the-difference	Analyzer vs VNA
vol25-rigexpert-aa-stick-aa-230-aa-600-aa-2000	RigExpert family
vol25-mfj-259-269-the-legacy-classics	MFJ-259/269
vol25-sark-110-pocket-vna-precursor-to-nanovna	Sark-110
vol25-full-instrument-vnas-keysight-rs-copper-mountain	Full-instrument VNAs
vol25-when-to-step-up-from-a-nanovna	When to step up
vol25-calibration-kits-the-cost-of-accurate-measurement	Cal kit cost

Vol 26 — Power / SWR / sig-gen

Anchor	Topic
vol26-through-line-wattmeters-bird-43-and-its-descendants	Bird 43
vol26-modern-cross-needle-swr-power-meters	Cross-needle meters
vol26-dummy-loads-the-load-that-doesnt-radiate	Dummy loads
vol26-rf-probes-high-impedance-voltage-measurement	RF probes
vol26-signal-generators-hp-agilent-rs-the-lab-gold-standard	Signal generators
vol26-sdr-as-signal-source-hackrf-bladerf-usrp	SDR as sig source
vol26-adf4351-adf4355-cheap-pll-synthesizer-boards	ADF4351
vol26-field-strength-meters-and-eirp-estimation	FSM / EIRP

Vol 27 — Spectrum analyzers

Anchor	Topic
vol27-spectrum-analyzer-vs-vna-vs-sdr-what-each-is-for	SA vs VNA vs SDR
vol27-tinysa-pocket-spectrum-analyzer-for-hams-and-hackers	TinySA
vol27-tinysa-ultra-to-5-3-ghz-with-tracking-gen	TinySA Ultra
vol27-tektronix-rsa306-rsa607	Tektronix RSA
vol27-signal-hound-usb-analyzers-bb60c-sm200b	Signal Hound
vol27-rs-handheld-spectrum-analyzers-fsh4-fsh8	R&S handhelds
vol27-tracking-generator-basics-swr-sweep-on-a-spectrum-analyzer	Tracking generator
vol27-harmonic-measurement-of-a-transmitter-through-an-antenna	Harmonic measurement
vol27-eirp-estimation-by-reciprocity	EIRP by reciprocity
vol27-near-field-probing-e-field-and-h-field-probes	Near-field probing

Vol 28 — Modeling software

Anchor	Topic
vol28-why-model-the-predict-before-build-philosophy	Predict before build
vol28-the-nec-family-nec-2-nec-4-nec-5	NEC family
vol28-4nec2-the-free-windows-frontend	4nec2
vol28-eznec-pro-the-de-facto-amateur-standard	EZNEC Pro+
vol28-mmana-gal-free-nec-derived-modeler	MMANA-GAL
vol28-openems-fdtd-time-domain-modeling	openEMS
vol28-the-nec-card-stack-input-file-syntax	NEC card stack
vol28-modeling-workflow-sketch-segment-run-interpret	Modeling workflow
vol28-optimizing-a-yagi-with-4nec2-worked-example	Yagi optimization
vol28-bench-validation-comparing-model-to-nanovna-sweep	Bench validation

Vol 29 — Use-case matrix per radio

Anchor	Topic
vol29-the-matrix-at-a-glance	Matrix at a glance
vol29-hackrf-one-wideband-1-mhz-6-ghz-tx-rx	HackRF One
vol29-rtl-sdr-v4-receive-only-hf-vhf-uhf	RTL-SDR V4
vol29-flipper-zero-sub-ghz-cc1101-433-mhz-ir-nfc	Flipper Zero
vol29-esp32-marauder-firmware-2-4-ghz-wi-fi-ble	ESP32 Marauder
vol29-wifi-pineapple-mark-vii-ac-2-4-5-ghz	WiFi Pineapple
vol29-opensourcesdrlab-portarf-hackrf-class-handheld-sdr	PortaRF
vol29-quansheng-uv-k5-144-430-mhz-handheld	Quansheng UV-K5
vol29-rayhunter-orbic-speed-rc400l-cellular-detection	Rayhunter
vol29-decision-graph-i-want-to-do-x-which-radio-antenna	Decision graph

Vol 30 — Multi-radio shared antennas

Anchor	Topic
vol30-the-problem-n-radios-m-bands-finite-case-real-estate	The N radios problem
vol30-the-three-sharing-strategies-wideband-multiplexing-switching	Three sharing strategies
vol30-strategy-1-wideband-antennas-as-multi-radio-servers	Wideband sharing
vol30-strategy-2-frequency-multiplexing-diplexers-triplexers-n-plexers	Frequency multiplexing
vol30-strategy-3-time-multiplexing-band-switching-matrices	Time multiplexing
vol30-the-tx-rx-problem-protecting-receivers-from-co-located-transmit	TX-RX problem
vol30-gps-why-its-almost-never-sharable	GPS exception
vol30-worked-example-consolidating-the-uconsole-from-7-antennas-to-3	uConsole worked example
vol30-the-efficiency-tax-of-sharing-what-you-actually-pay	Efficiency tax
vol30-pin-diode-mems-and-mechanical-rf-switches	PIN/MEMS/mechanical switches

Vol 31 — Regulatory & RF safety

Anchor	Topic
vol31-the-three-regulatory-questions	Three regulatory questions
vol31-fcc-part-15-unlicensed-devices-and-the-ism-bands	Part 15
vol31-fcc-part-97-amateur-radio	Part 97
vol31-fcc-part-22-24-27-90-licensed-services	Licensed services
vol31-itu-regions-and-frequency-allocation	ITU regions
vol31-erp-vs-eirp-different-references-same-idea	ERP vs EIRP
vol31-mpe-maximum-permissible-exposure-tables	MPE tables
vol31-oet-65-compliance-workflow	OET-65 workflow
vol31-common-mode-currents-and-rfi-to-neighbors	Common-mode RFI
vol31-the-receive-only-carve-out	Receive-only carve-out

Vol 32 — Antenna farms & multi-antenna systems

Anchor	Topic
vol32-the-multi-antenna-posture-why-stack-or-array	Multi-antenna posture
vol32-vertical-stacking-2-bay-3-bay-4-bay-yagis	Vertical stacking
vol32-horizontal-stacking-phasing-for-fixed-direction-gain	Horizontal stacking
vol32-phased-verticals-broadside-end-fire-cardioid	Phased verticals
vol32-beverage-arrays-for-low-band-receive	Beverage arrays
vol32-switching-matrices-top-ten-devices-array-solutions	Switching matrices
vol32-automatic-antenna-selectors-per-band	Automatic selectors
vol32-so2r-and-multi-op-station-design	SO2R

Vol 33 — This volume

Anchor	Topic
vol33-a-z-glossary	A-Z glossary
vol33-canonical-anchor-index-for-inbound-cross-deep-dive-links	Canonical anchor index (this section)

Anchor-stability discipline: once a heading is committed and published, its slug is frozen. Other deep dives may already link to it. If you have to rename a heading (genuine error in the original wording, not a stylistic preference), search the entire Hack Tools/ tree for the old anchor first and update both ends in the same commit.

18. Resources

Primary canonical references

• ARRL Antenna Book (25th edition and beyond) — the desk-side reference for amateur antenna engineering. https://home.arrl.org/action/Shop/Antenna-Book
• Balanis, Antenna Theory: Analysis and Design (4th ed., 2016) — the graduate-level reference, equations on every page.
• Stutzman & Thiele, Antenna Theory and Design (3rd ed., 2012) — equally rigorous; often used as the alternative undergraduate text.
• Kraus, Antennas (3rd ed., 2001) — the historical classic; published originally 1950, still cited.
• ARRL Handbook for Radio Communications — annual; chapters on transmission lines, matching, and operation.

Software references

• NEC-2 user manual (Burke / Poggio, LLNL, 1981) — https://www.nec2.org (full PDF)
• NEC-4 documentation — restricted; license through LLNL TechTransfer
• 4nec2 user manual (Arie Voors, PA3HBB) — https://www.qsl.net/4nec2/
• EZNEC documentation (Roy Lewallen W7EL) — https://eznec.com (legacy)
• MMANA-GAL — http://gal-ana.de/basicmm/en/
• openEMS user manual — https://openems.de
• NanoVNA-Saver documentation — https://github.com/NanoVNA-Saver/nanovna-saver
• NanoVNA Wiki — https://nanovna.com

Vendor and parts catalogs

• DX Engineering — antennas, parts, and accessories. https://www.dxengineering.com
• Mini-Circuits — RF components catalogue (splitters / combiners / couplers / mixers / amplifiers). https://www.minicircuits.com
• Fair-Rite — ferrite-mix application notes and selection guide. https://www.fair-rite.com
• Amidon — same product line, US distributor. https://www.amidoncorp.com
• Times Microwave — LMR-240/400/600 datasheets. https://www.timesmicrowave.com

Standards and regulation

• FCC OET Bulletin 65 (1997, with 2024 supplement) — MPE workflow. https://www.fcc.gov/general/oet-bulletins-line
• IEEE C95.1-2019 — IEEE Standard for Safety Levels with Respect to Human Exposure to Electric, Magnetic, and Electromagnetic Fields, 0 Hz to 300 GHz.
• FCC Office of Engineering and Technology — https://www.fcc.gov/general/office-engineering-and-technology
• NEC (National Electrical Code) 250 & 810 — grounding for AC distribution and for radio antenna installations; published by NFPA.
• ITU Radio Regulations — international frequency allocation by region.

Author / historical archives

• L.B. Cebik W4RNL papers — antenna analysis and modeling archives (cebik.com / various mirror sites).
• Walter Maxwell W2DU, Reflections III: Transmission Lines and Antennas — definitive treatment of common-mode currents and W2DU bead-string chokes.
• Roy Lewallen W7EL, EZNEC documentation — antenna modeling fundamentals (referenced by every NEC tutorial since).

Sibling deep dives (Hack Tools cross-links)

• ../HackRF One/ — wideband SDR, prime consumer of the discone + LMR-400 chain
• ../OpenSourceSDRLab PortaRF/ — handheld SDR (HackRF sibling)
• ../RTL-SDR/ — receive-only SDR
• ../Flipper Zero/ — sub-GHz CC1101 front-end
• ../ESP32 Marauder Firmware/ — 2.4 GHz Wi-Fi/BT
• ../WiFi Pineapple/ — purpose-built wireless-auditing antennas
• ../Quansheng UV-K5/ — VHF/UHF handheld
• ../Hacker Tradecraft/ — RF tradecraft cluster (Vols 13-15 link into this deep dive)

Cross-deep-dive linking convention

All inbound links from sibling deep dives should use the vol{NN}-<heading-slug> anchor convention documented in Section 17 — Canonical anchor index. Anchor stability is non-negotiable; once a heading is committed, its slug is frozen.