1-1/4 MTR antenna any good for UHF airband

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1-1/4 MTR antenna any good for UHF airband

Postby RCB91 » Tue May 01, 2018 5:35 pm

Hi
Would a 1-1/4 metre antenna be any good for monitoring UHF airband with it being around 222mhz would it have enough bandwidth just a. Idea I have not been able to get any info would appreciate any help
Many thanks in advance
Richard
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Re: 1-1/4 MTR antenna any good for UHF airband

Postby G4RMT » Tue May 01, 2018 8:00 pm

Well, assuming it's a simple quarter wave at 220MHz (a band we don't have in the UK) then it has no gain, so you will be down to about -3dB by the time you get to 240 or so, and then downhill to the top end of the 300MHz UHF airband. It behaves as a non-resonant antenna once you move away, so performance will be not really that exciting - but aircraft signals are usually line of sight and pretty strong, so it will still do something. Cutting it down to the right length for the centre of the band doesn't really help that much, because the shorter length produces even less signal once you move away from resonance.
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Re: 1-1/4 MTR antenna any good for UHF airband

Postby RCB91 » Tue May 01, 2018 9:34 pm

Many thanks for replying very interesting
Richard
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Re: 1-1/4 MTR antenna any good for UHF airband

Postby m0lsx » Tue May 01, 2018 9:49 pm

As above. Personally I mostly use either good quality, longish & well earthed single band whips for 10, 6, 4 or 2 meters or occasionally small micro mag dual band antennas for 2 & 70cm. They all work, but all are compromise antennas. But for my money the best for general listening are the small & cheap micro mags. They have no lossy loading coils & work very well for what they are.
In general the more gain an antenna has, at it designed working frequency, the less well it works away from that designed frequency. So a simple antenna can often be the best option away from the designed operating frequency.
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Re: 1-1/4 MTR antenna any good for UHF airband

Postby Chris P » Wed May 02, 2018 6:41 am

The bowtie is very popular with UHF airband listeners and gets good reports on Fighter control
https://ukradioscanning.com/viewtopic.p ... 015#p32692
Regards Chris aka G8FFF nipper or tazmin88
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