Discussion in 'Antennas, Feedlines, Towers & Rotors' started by KC0BUS, Jun 16, 2019.
They guy is a multi-forum troll.
BRAVO, YOU HIT THE NAIL RIGHT ON THE HEAD.
Not a DIY or Amateur project, in fact illegal.
You came to the right place to learn how to conduct illegal activity and endanger the public.
Example one of the brain children here came up with a great idea: Use a Mag Mount Antenna on a Aluminum of Fabric skinned aircraft. Brilliant idea.
However being a private pilot and you mentioned 2m/70cm you can use an HT which will reach further than any mobile or base at altitude, and complies with FAA regulations.
Our club used to fly 172s tracking animals for a local university using a VHF DF antenna clamped to a wing strut. I'm not sure but I think it was done under a 337 and it allowed us to install/remove the antenna whenever we needed. I would talk to a local A&P-IA (Inspection Authorization) mechanic and see if he thinks it would be something he could get approved. If you can, find an IA who works with crop dusters.
I like the idea of using an inspection plate, but I wouldn't do it on a fabric airplane, and only with a small antenna like a 6" uhf antenna. And it's not legal, so I wouldn't do it on my airplane, but if I saw someone else do it, it wouldn't bother me much. Compared to all of the other stuff I see, not yelling "clear", not doing runups, not doing much of a preflight, the 6" antenna on an inspection plate on the belly would be way down the list.
The best way though is just to have a real, legal antenna installed by an A&P. I think it's just a minor alteration. A VHF (2m) antenna might also work on UHF, since it's 3/4 wave. It would normally have a strange elevation pattern, but that might work in your favor in an airplane to give more downtilt.
"Someone I know" used to fly his J3 Cub around talking on his HT connected to the ELT antenna. It worked fine since he used low power and had a lot of elevation (usually around 500 feet). But of course that's not legal either and he wouldn't recommend it
Look at KL7DTH qrz page.
He deploys a trailing wire, up to 300 feet behind Cessna 185.
Lee knows what he's doing for aeronautical mobile, he's taken that particular setup to the North Pole a few times.... and LANDED it.
Dad installed a 2m rig in his 182. A 1/4 wave whip is about the same length as a VHF com antenna. The 2m was installed under the belly.
My Cherokee has a hole in the belly where the ADF loop used to be, a whip antenna can be easily installed there. The ADF sense wire could be used for mabe 10m or 6m, with the airframe as a counterpoise.
I had several nice QSOs on 52 simplex today as I flew my '182 from the LA Basin to near Prescott. I have a TM-D710 and an outside antenna.
I have had good luck with these two methods:
1. I used a BNC cable with suction cups that allowed me to put the rubber duck up against one of the windows and run a cable to the HT. It worked fine.
2. One airplane had an extra comm antenna and I just hooked it to the HT. While cut for about 20 MHz too low, the 2 meter HT didn't seem to care and it worked fine.
If you own the airplane, just buy the correct antenna and have it installed. There are antennas that cover the 2 meters and/or 440 for aircraft. If you are cheap you can always get a cheap bent wire comm antenna and cut a few inches off the end to move the center frequency to 2 meters or cut more off for 440.
HF is a different story and not really doable if you don't own the airplane. The common way to do it is to run from the cabin top to the top of the vertical stabilizer and then forward to a wing tip and use an SGC tuner. They have a whole chapter on aircraft installs.
Don't forget the audio end of it. Not all avionics shops know anything about interfacing ham gear to the intercom system. Your local Civil Air Patrol is probably a good source of info, they use non-aircraft FM radios. For a temporary setup I just used the aircraft headset adapter Icom sells for their airband HT because my 2 meter Icom has the exact same jacks and pinouts as my Icom airband HT. If you try and just talk into the radio you will get the following replies:
"What's that noise?"
"Who keeps playing engine noises?"
"Is that an airplane?"
My go-to method of starting a QSO was to come up simplex on the OUTPUT side of a repeater and switch over to a simplex freq. Not enough people are on 146.52 to always find anyone.
APRS is fun from airplanes and if you had a way to do APRS and talk you could have a beacon like CALL ME 146.52.