The International Cessna^® 170 Association

"New" radios (w/King 135A) going in 39A and I am wondering where people mount the GPS antenna? I do not want to mount it in the center of the fuselage (love the line) and was thinking small cover inboard of the flaps (like Gary's). Any other ideas out there? Pics?

Thanks! Chris

Chris,

Comant makes combination VHF/GPS antennas. http://www.comant.com/pdfs/[ci%202480-200]2006.pdf

If you've already bought your GPS antenna a rule of thumb is to place it at least three feet from your comm. antenna(s).

I originally intended to go with the combo VHF/GPS but the Comant guy talked me out of it...I think the actual reason was compatability (I was going to hook it up to a portable, not a panel mount). Check with their engineering guru, he's pretty helpful (I had his cell number at one time, but can't seem to find it here in the mess-on-the-desk).

As far as location, my avionics guy says for IFR, appropriate spacing is necessary, but VFR use isn't critical...the unit really only needs a couple of satellites to be effective. And I think that's the rationale - that the VHF antennas inadvertantly pirate the GPS signal if the antennas are too close together.

Also, if you decide on seperate installations (like I finally did), there's a glut of good used Garmin antennas available since all the IFR guys are switching to WAAS.

I got lucky...there's already a patch on top of my fuselage where sombody removed an old ADF antenna or something - the little teardrop Garmin antenna fits perfectly, right on top of the patch.

Good luck...

Good gouge on spacing. The King 135A is not an IFR GPS but, the RNAV is an IFR unit. I'll check with the company to find out if the comba may work for me. If not, Gary at SFQ has his mounted on the small plate over the flap root cover. Seems like a great place that is really only a flat piece of metal screwed over a hole....easily replaceable if I would ever get rid of the 135.