Bob archer antenna

[FORANE]

Originally Posted by Sam Buchanan

There have also been reports of significant 'shadowing' (not sure if that is a technical term) supposedly from the proximity of the antenna to the metal wing. The Archer COM antenna installed in a composite aircraft that allows vertical orientation would most likely be a good performer.

I have an Archer nav and com antenna in my Lancair. The nav antenna works well. The com antenna is in the fuselage bonded to the inside behind the baggage area. As a result I see shadowing in the direction of aircraft travel - the pilot and motor blocks the signal. Compared to the Red tail antenna from Delta pop aviation that was on our RV, the Archer antenna is marginally acceptable.

Originally Posted by 506DC

the COM was not consistent causing the controllers sometimes unable to hear my transmissions. I could not find anything wrong but decided to replace the Bob Archer COM antenna on the wingtip with a bent COM antenna on the belly right under the passenger seat in my RV-4. Immediately everything fixed itself and my range at least doubled with better voice reception and never had trouble with the fuselage blocking reception again. I really did not notice any substantial decrease in speeds but even if I did, I would trade for the superior communications and no gremlins.

This is consistent with my experience, and expect would be the same for the OP.

[Sam Buchanan]

Originally Posted by FORANE

I have an Archer nav and com antenna in my Lancair. The nav antenna works well. The com antenna is in the fuselage bonded to the inside behind the baggage area. As a result I see shadowing in the direction of aircraft travel - the pilot and motor blocks the signal. Compared to the Red tail antenna from Delta pop aviation that was on our RV, the Archer antenna is marginally acceptable.
.

I have no personal experience with composite aircraft but if building one I think the only place I would locate an Archer COM antenna is in the vertical stab. But there isn't any operational reason not to use a good whip antenna unless the aircraft is designed for racing.

[FORANE]

Originally Posted by Sam Buchanan

I have no personal experience with composite aircraft but if building one I think the only place I would locate an Archer COM antenna is in the vertical stab. But there isn't any operational reason not to use a good whip antenna unless the aircraft is designed for racing.

I have a whip in the vertical stab. It isn't great either; believe that is due at least in part to insufficient ground plane. At one point it suffered poor transmit range and turned out to be due to internal cable damage secondary to cable bouncing in turbulence right at antenna connector as result of a poorly secured cable.

[Sam Buchanan]

Originally Posted by Sam Buchanan

I have no personal experience with composite aircraft but if building one I think the only place I would locate an Archer COM antenna is in the vertical stab. But there isn't any operational reason not to use a good whip antenna unless the aircraft is designed for racing.

Originally Posted by FORANE

I have a whip in the vertical stab. It isn't great either; believe that is due at least in part to insufficient ground plane. At one point it suffered poor transmit range and turned out to be due to internal cable damage secondary to cable bouncing in turbulence right at antenna connector as result of a poorly secured cable.

I was referring to an external whip antenna.

Yes, providing a good ground plane for a COM antenna in the vertical stab would be problematic. Maybe extend wire ground plane radials into the horiz stab? Makes an external whip look simple.