Is this REALLY what a mobile UHF/446 antenna looks like??

Licence free two-way radio services that now includes both FM and digital channels. Discuss models, modifications and other similar worldwide standards such as FRS and GMRS.
mr_m3
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Joined: 12 Jan 2008, 22:09

Re: Is this REALLY what a mobile UHF/446 antenna looks like??

Post by mr_m3 »

Just something nobody else has mentioned but when building antennas you have to take the velocity factor of the material the antenna is made out of into account, this is because the Signal slows down while traveling through the antenna and you need to correct for this.

This is because electricity travels at different speeds through different materials.

You generally want your antennas a bit longer than the calculated wavelength to account for the velocity factor of the antenna material so I always make mine around 20% oversize for trimming purposes, obviously you’d struggle todo this without a S.W.R meter.

Without an swr meter I would probably buy an antenna because you can’t check the SWR of what you make and your nice Yaesu transceiver sounds faaaar more expensive then a pre-made antenna.


I’ve had great results stacking 3 half waves made from rg58coax with a 1/4 wave ground-planes on the bottom, google coax colinear they’re really simple! But again I can’t stress how important a swr meter is
26TM069
M3UBO-----> 2E0FML---->2E0PUC
mr_m3
Super Member
Super Member
Posts: 444
Joined: 12 Jan 2008, 22:09

Re: Is this REALLY what a mobile UHF/446 antenna looks like??

Post by mr_m3 »

Just noticed how old this thread is ! Now don’t I feel a tit ! 😅😅
26TM069
M3UBO-----> 2E0FML---->2E0PUC
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