Help with COM antenna mount-Champ

[Autogateman]

Does anyone have pictures of how a COM antenna base is mounted to a wing root fairing on a Champ? Looking to install it where this one is.

 

[Desert7GCBC]

I just installed that antenna on my Citabria for a backup with a handheld radio. The antenna was ~$130 from Spruce. With hindsight, spending a few extra bucks and buying the antenna with the cable already installed would have eliminated stripping wires and soldering thereby simplifying the installation.

The fairing material is thin so I put a 3"X4" aluminum doubler on the back side of the fairing strip with a small pulled rivet at each corner to stiffen it up. Drilling the hole with a step drill worked well instead of using a drill bit.

 

[Champdriver]

I did pretty much the same on my 7AC with the doubler plate behind the fairing strip.

 

[Autogateman]

OK so all this I'm reading about needing some 24 inch diameter ground plane is not correct?

 

[Bob Turner]

The airframe is the ground plane. It is not perfect, but then, neither is a 24" diameter disc. Nobody does the disc, except maybe plastic airplanes.

Hard to believe they get $130 for that coat hanger antenna - get a used Comant from a salvage outfit.

 

[Autogateman]

The airframe is the ground plane. It is not perfect, but then, neither is a 24" diameter disc. Nobody does the disc, except maybe plastic airplanes.

Hard to believe they get $130 for that coat hanger antenna - get a used Comant from a salvage outfit.

Luckily I already had the antenna and the cable. I was also given a Becker radio still in the box that fits in a gauge hole but I want to try hooking the antenna to my handheld before I do any of that.

 

[Bob Turner]

Just make sure the cable is RG58 or RG400. Some folks cheap out and use Radio Shack cable. That does not work.

Also, hand helds have limited transmit power. We had a difficult time with the tower before switching to the GTR-200.

We also had trouble with the Becker. After three trips to the repair facility we installed a 200, and have not had problems since.

 

[Autogateman]

Just make sure the cable is RG58 or RG400. Some folks cheap out and use Radio Shack cable. That does not work.

Also, hand helds have limited transmit power. We had a difficult time with the tower before switching to the GTR-200.

We also had trouble with the Becker. After three trips to the repair facility we installed a 200, and have not had problems since.

I can understand why the Becker would have trouble because it is no more powerful than the handheld at six Watts. The cable I have came with the antenna and has the soldered connections already on one end.

 

[Bob Turner]

Our Becker simply stopped working. Minimum repair charge $600 plus two way shipping to Florida plus down time. GTR was $1200 at the time. Much better radio, world's best intercom.

Modern radios just use standard BNC connectors. No soldering involved. Cables are crimped.

 

[Autogateman]

Our Becker simply stopped working. Minimum repair charge $600 plus two way shipping to Florida plus down time. GTR was $1200 at the time. Much better radio, world's best intercom.

Modern radios just use standard BNC connectors. No soldering involved. Cables are crimped.

I was referring to the soldered connections that connect the cable to the antenna.

 

[JackC]

Had a avionics buddy who owned his own shop clean mine up.

We installed on the metal fairing strip, make sure it’s bare metal and scuffed up on the bottom of the antenna and where it’s mounting on the strip. We already had a doubler already there from the old antenna, as others said its thin metal, we just redrilled for the new antenna which thankfully had a wider base than the old one.

After install seal around the base of antenna

Use RG400 shielded cable, heat shrink the properly crimped connectors

Comant antenna (CI 121) is good go to

For the portable the sporties PJ is great

Antenna

Comant VHF Communication Antenna CI-121 | Aircraft Spruce ®

Comant VHF Communication Antenna CI-121 Comants four through hole mount whip style VHF communication antenna with BNC port.

www.aircraftspruce.com

Cable

Coaxial Cable RG 400 Certified | Aircraft Spruce ®

Coaxial Cable RG 400 Certified Standard cable for radio installations. Double shielded stranded conductor, MIL-DTL-17 spec

www.aircraftspruce.com

BNC connectors and heat shrink over the crimps

 

[Autogateman]

Had a avionics buddy who owned his own shop clean mine up.

We installed on the metal fairing strip, make sure it’s bare metal and scuffed up on the bottom of the antenna and where it’s mounting on the strip. We already had a doubler already there from the old antenna, as others said its thin metal, we just redrilled for the new antenna which thankfully had a wider base than the old one.

After install seal around the base of antenna

Use RG400 shielded cable, heat shrink the properly crimped connectors

Comant antenna (CI 121) is good go to

For the portable the sporties PJ is great

Antenna

Comant VHF Communication Antenna CI-121 | Aircraft Spruce ®

Comant VHF Communication Antenna CI-121 Comants four through hole mount whip style VHF communication antenna with BNC port.

www.aircraftspruce.com

Cable

Coaxial Cable RG 400 Certified | Aircraft Spruce ®

Coaxial Cable RG 400 Certified Standard cable for radio installations. Double shielded stranded conductor, MIL-DTL-17 spec

www.aircraftspruce.com

BNC connectors and heat shrink over the crimps

Thanks! I have the Sportys PJ2+