118.0 to 148.0 and 420.0 to 450.0 antenna

jnmeade

jnmeade

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Eastern Iowa
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Jim Meade
I'm looking for an antenna for my new pickup. It will be mainly used for 2m and 70cm FM amateur service, but I'd like it optimized for use on aviation AM bands, as I may use it as a ground station for glider operations.

Anyone have any idea where to find such an antenna? Or, how hard is it to make one?

I don't know if the 2m band width sought is too wide for one antenna. If it is, this turns into a tri-bander of sorts.

Two separate antennas is not an attractive solution, as I don't have enough inputs on the radio. I'd have to use a splitter and would prefer to avoid it.

So, my main priority is one dual-bander.
TIA
 
They definitely make 70cm/2M antennas. They'll have a loading coil about half way up typically. I used one frequently back in the day that we were busy in the repeater activity in the area. These things aren't tremendously broadbanded but work better than the rubber coated dummy load on your handheld. My wife used to have little RF amp under the seat of her minivan to boost the power (also had a receive preamp). I never bothered. I might still have one or two of these around here somewhere.

Frankly, for the aviation use, I'd just make a quarterwave whip. There's really not too much point in trying to build a triband antenna. Just stick it on a mag mount and hang it up as necessary.
 
I think you are going to have a problem without a tuner. Off the shelf, the typical suspects such as Diamond or Comet are tuned up in the middle of the band. Dropping into the aviation band Id expect our SWRs to be rather high. Id guess 3:1 or worse. If you tried to tune it to the aviation band and QSOed on 2m/440 for more than a little bit, your gonna smoke your rig in short order.

Besides, I have yet to see a rig that will do AM transmit off a dual amateur band radio anyway. A duplexer is cheap if you wanted to try and go with a second radio, but I do believe this is a one legged man in an ass kickin contests without some serious work with an iron and some G2.
 
jnmeade said:
I'll run it off a Yaesu 857D.
Click to expand...

The 857D will not transmit in the aviation band even if you do the extended TX mod. It only is capable from 1.8-56 MHz, 137-154 MzHz, and 420-470 MHz.
(Not to mention it would be illegal to use it on the air bands).
 
I just use a dual band (2m/70cm) antenna on my Jeep. I'm not transmitting on the aviation band, so VSWR isn't really a big issue. Receives fine on those frequencies. Glass mount from Larson.
 
My friend who retired from building aircraft antennas for Rockwell Collins designed one for me. I'll have to make it, but it's not that bad.
 
The Comet CA-2x4SR is the broadest dual band mobile antenna I have found with the exception of a NilJon. I own 2 of the 2x4's and have used them for years. I had one of the early NilJon's and while it was VERY broadband the durability was not great. It is currently in pieces in the hangar. Another option is a discone however it isn't really a mobile antenna.
 
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