I have had conversations with other planes that were over 100 miles away, now much degradation could there be?

As for placement, I put the antenna under the pilot's seat, just forward of the spar. In fact, the aft two machine screws for the antenna go through the spar flange and the front two are secured to platenuts on doubler. I am thinking of adding a second radio and will put it on the other side and mount it the same way. That way you don't have to run those thick cables through the spar, which as you know has limited space to pass wires through.


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As far as I understand, the Archer wingtip antenna is for Nav (VOR) -- horizontal polarization.

Or is there also a vertical Archer? I can imagine that you could get partially vertical going from bottom of rib and up and out towards tip before you have to bend it horizontal.

Finn

Yes, there is an Archer cut for the com band. And yes, you want to run the leading edge diagonally up/down as much as possible (due to the asymmetric tip shape I ran mine from the top of the rib down to the fiberglass wing tip.) And yes, as previously noted, it is not as good (but not horrible) as a ?real? vertically polarized antenna. Since nav signals are horizontally polarized, the Archer nav antenna works quite well.

I ham radio guy. I agree. It is not practically significant. It is however something, polarization does matter. Not to drive into the weeds, RF has an electrical field and magnetic field (electromagnetic field). Polarization matches the electrical field. The orientation of element of the antenna is the polarization. Matching the polarization of the RF antenna of incoming signal gets maximum signal. If the RF antenna polarization does not match there is a loss by the factor of cosine of the angle between the polarization of the RF antenna and the signal. Theoretically it could be ZERO! However there is no pure polarization but antennas can have deep nulls and be directional. Often RF signals bounce around and polarization is mixed. Usually a VHF line of sight signal does not change much unless it bounces off objects. We are rocking the unbalanced dipole in a metal airplane. At 12,000 feet you might get 100 miles with 10 watts and a coat hanger in your mouth. Ha ha. (don't try it)

I did an experiment with an FM radio broadcast transmitter (FCC Part 15, power 100 mw) whip antenna vertical. I set up a receiver and determined line of sight range, a few blocks with receiver antenna vertical. I laid the receiving antenna down horizontal. I still got the signal but lots of static, signal became weak. Put receiver antenna back vertical and signal was again solid. If you noticed bent whips give you at least 10" to 13" vertical polarization. The electrical length is still 1/4 wave or about 20". Folding antennas is a bit of an art. It works to be sure but it is not without some losses. So when you say you got 100 miles with a bent whip, a pure vertical dipole may give you 130 or 150 miles range at 12,000 feet.

I did a similar thing in my old RV-4. Great location.

If you're using 2 comm antennas, would it make any sense to use the wing as a ground plane by mounting 1 whip antenna each on the underside middle of each wing to maximize distance between comm antennas and VOR antennas (assuming tip mounted VOR) ??