Thorp Air Command - T18.net

Hey fellas,

If you please, I'd like to survey the locations and types of Com antennas everyone is using, and likewise, Xpndr, ELT, and Nav as well. The old thorplist has good info on Bob Archer's wingtip antennas, but let's see what others are using.

I've got a simple com-type whip antenna that I think would work on top behind the canopy and a transponder stub to go below, just ahead of the main spar. The thought is to use the whisker-type nav antenna on top of the vertical tail too.

I'm curious, are there problems with a com antenna being bent too far back to use on the belly? (ground clearance issues), how does landing gear affect it? How much difference is there from a wire whip and more expensive types? Maybe behind the canopy is just as good. Or, how far away from a vent tube does the transponder stub have to be?

This seems to be a topic we could address.
Appreciate your responses,

Les Krumel

LES, I have a cheep stainless bent vhf antenna on the bottem of my plane centered just aft of the gear and it has worked great for the past 10 years. I did replace the xpondeer antennas a few times because they were the cheep rod kind which can break off easly during a wash job. I replaced it with the enclosed blade kind, much stronger. As far as a nav antenna, I don't have one as I have a AIR NAV 2000c GPS which I use as my sole navigational source.A great feature that I think is essential out here in the West is the color terrain clearance feature. Works good, lasts a long time. Paul MacMichael N 174p

Bent comm antenna on the bottom is the way to go. I used the top aft of canopy location for years and found myself losing contact with ground stations as I flew away from them. Seems the tail was blocking the signal. Also, the top mount would interfer with the Tru-Trac autopilot (commanded a slight climb with every transmission.) Bottom mount on the floor pan solved all these problems. My IFF is under the right seat and has, on occasion, been bloced to ground stations by the gear. Don't have an answer for that. Used Archer's wing-tip setup with fair results. Abandoned the VOR when GPS came out.

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Bob Highley
N711SH
SN 835
KLAL

I copied Bob....I have Com 1 on the top half way between the fin and canopy. Com 2 is located on the lower spar box cover. As Bob mentioned the top antenna interfered with the Trutrac until I installed a filter. The IFF is in the passenger seat belly skin about 6" from the side. Never had a VOR antenna. GPS antenna is located on the instrument panel cover. It measures 1.25 x 1.25 x .500.

Les,
I have the 45 bent SS rod antenna for Com and the stub xpndr on the bottom below the baggage compartment. The concern was to get it further from the gear and prop. Works good, but occasionally may not be as strong on the ground. I routinely cover my plane, so I appreciate not having the whip on top. The ELT is bent under the canopy. The GPS is bluetooth and also mounted under the canopy. I have both an Archer Com and NAV antenna for sale if interested.
Terry Adams
N51079
KSCK

_________________
[b]Terry[/b]

I am looking for a comm antenna

Please email me or PM if you would consider selling.

alcocklake@gmaildotcom

Tim Brown
C-GABY

Antennae are fairly easy to make.

You guys are great. Thanks for the good info on antennas, and for answering about fuel primers too. Really glad I asked.

Les.