UHF antenna problem

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batdude
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UHF antenna problem

Post by batdude »

i have a high gain (moto spectrum) that's tuned to 449Mhz on the top of my tahoe.

problem - i also need to transmit on 467 mhz for GMRS (repeater input)


the spectrum is going high swr on GMRS and i don't want to smoke my PA.

transmit power is mmmmmmm....75w on ham and 50w on GMRS (it's a 110w MCS)

ideas?


doug
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Tom in D.C.
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What radios do you own?: Progreso soup can with CRT

UHF antenna setup

Post by Tom in D.C. »

Suggest you cut it for 458 mHz and split the difference. A typical antenna which has 6db gain will have a bandwidth of around 6 mHz with a max SWR at the "edges" of the 6 mHz of what? - - maybe 3:1. And perhaps cut the power back on both ham and GMRS to save the final amp strain.

But an 18 mHz bandwidth is a real challenge for a mobile, no matter how you slice/view/handle/cope with - - it.

Or maybe install two antennas and an MFJ two-way coax switch.

Tom, W2NJS
...in D.C.
USPSS
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Post by USPSS »

Simple solution, Install one of the THICK wide band quarterwaves, they will go 1.15.1 in about a 60Mhz window all day, you probably will not see any difference in performance either.
Comtelco has the widest with a .120 whip Antennex, Maxrad have .100 whips in this case thicker is better.
Stan Glass


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jim
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Post by jim »

Install 2 UHF antennas with a tee. Yes- it will work just fine. I do it with 33/46 lowband and it matches perfectly.
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