Posted: 8/19/2009 09:12:34
I own a 2002 Interplane skyboy (composite body) and I use an I Com hand held for communication. I want to install an external antenna to get better reception. Any recommendations on what would work good for my situation?
Posted: 8/19/2009 11:30:07
Well, can't say as I can help you very much- but if you do a search in the SA Archives for "Weir" and check the author box, you'll get several articles for building antennas. Doesn't address handhelds, but suspect you can find something that can help
Posted: 8/19/2009 20:29:57
You need a ground plane under the composite material for the antenna to work properly. It should be at least 24" x 24". Heavy aluminum foil glued on with contact cement should work OK. COMANT has some good articles about ground planes. There is also a FAA circular 43--- about installation. I'd buy an antenna and mount it above the ground plane. You can make one using a BNC feed thru for the mount and a BNC connector with a 24" center conductor make from probably 1/32" spring steel wire you can buy a any hobby shop. Just search GOOGLE for aircraft antennas, aircraft antenna ground planes, etc. A commercial antenna would look nicer and probably hold up better.
Posted: 8/20/2009 10:11:30
ks, Rich. This info will be very helpful.
Posted: 8/20/2009 19:34:48
The ground plane/wire approach will certainly work well but with a composite structure, there is no need to hang wires on the outside of the aircraft. Other than graphite, composite materials are radio frequency transparent. Jim Weir's company, RST Engineering, sells a nice antenna building kit. Here is the link:
It has enough material in the kit to build all the antennas your heart will desire and they work really well.
Posted: 8/20/2009 19:51:03
I have a comant CI-121 on top and a CI-122 on the bottom. Shop around and you can find them cheaper than aircraft spruce. They have a nice housing which I liked and I wanted them to match.
I recommend the $20 generic transponder antenna.
If you can mount inside the airplane then the RA millers from aircraft spruce are good or you can use their composite aircraft solution.
For the ground plane you don't have to have a solid sheet of metal. 2" aluminum tape in an X works pretty well from what I've read. AC43-13 and aerolectric are good sources for info on this.
Posted: 8/21/2009 10:42:09
However you do it and with whatever material, I suggest you keep it as simple as possible. You may want to contact a local amateur radio operator (HAM) and ask him/her to help tune the antenna for your frequencies, decide on the type of coaxial antenna wire to use and wiring connections questions. Most hams have the antenna analyzer instruments to help insure success and they will often "jump" at the chance to help. This may help you a lot.