Antennas
Antennas: 8 guides.
01
70 cm balcony/roof antenna: J-pole, collinear, mounting
How to move a 70 cm antenna out onto your balcony or roof and dramatically boost hotspot coverage: J-pole and Slim Jim from 450 Ω ladder line, collinears, ready-made Diamond and Nagoya whips…
Antennas
02
70 cm collinear antenna: calculation and building from coax
A coaxial collinear for the 70 cm amateur band (430–440 MHz) built by hand: how in-phase half-wave sections work, calculating length with the cable's velocity factor…
Antennas
03
Antenna SWR: how to read the chart and fix a high SWR
SWR (VSWR) in plain words: what reflected power is and why a high SWR heats up and can burn out the radio's power amplifier.
Antennas
04
Coax for 70 cm: RG-58, RG-213 or LMR-400
Which coax to use at 433 MHz: RG-58, RG-213 or LMR-400. Where feedline loss comes from, why length and every connector matter, and how much signal actually…
Antennas
05
DIY 1/4λ antenna for 70 cm: math, soldering, SWR
How to build a quarter-wave ground plane whip antenna with radials for 433–446 MHz for a DMR hotspot or base: length formula, four radials, soldering on…
Antennas
06
NanoVNA: how to measure SWR and tune an antenna
NanoVNA — a cheap pocket-sized vector network analyzer. How it works (two ports, a screen), why open/short/load calibration is needed before every measurement…
Antennas
07
SMA, BNC, PL-259 and N connectors: what goes where, and how not to mix them up
A breakdown of the antenna connectors on radios and hotspots: SMA male/female, the bayonet BNC, the UHF-series PL-259/SO-239 and the rugged N-type.
Antennas
08
Stock antenna or Nagoya NA-771: is it worth switching
The radio's rubber stock antenna versus the Nagoya NA-771: where the real gain is, why matching and the connector matter, and why the market is flooded with fakes. An honest breakdown.
Antennas