Marker Beacon Antenna Construction

[tx_jayhawk]

I understand Archer recommends a 40" piece of "something" for the MB antenna. I see he sells a copper foil jobbie, but I'm planning to make my own.

Any pros or cons of using aluminum vs. coax? I'm leaning towards coax, as it would obviously be a little more straightforward to install connectors on. If using coax, I assume I should be stripping all of the shielding off so that only the center conductor (and insulation) remains? Or shoudl a reduced portion of shielding remain?

Thanks,
Scott

[kentb]

Originally Posted by tx_jayhawk

I understand Archer recommends a 40" piece of "something" for the MB antenna. I see he sells a copper foil jobbie, but I'm planning to make my own.

Any pros or cons of using aluminum vs. coax? I'm leaning towards coax, as it would obviously be a little more straightforward to install connectors on. If using coax, I assume I should be stripping all of the shielding off so that only the center conductor (and insulation) remains? Or shoudl a reduced portion of shielding remain?

Thanks,
Scott

I stripped off 40" of shielding and put a BNC on the end. This I fiber-glassed into the edge of the wing tip in a couple of spots. I works just fine.



Kent

[gmcjetpilot]

Nice Kent. I might add if you want to minimize to coax run to the wingtip consider the lower cowl. Personally have not tried it but an acquaintance tried a VOR antenna and another a transponder antenna in the lower cowl with fair results. Since the marker is so directional, basically straight up in a fan shape I would think the lower cowl adequate, but not as good as the wing tip. Of course you need to break/make the coax connection with cowl removal, unless you support it off the engine or air box some how.

The nice thing is the polarization of the signal is such that a horizontal element is OK, which it is not so cool for COM antennas, which have vertical polarization.

[tx_jayhawk]

Thanks Kent.

If I understand the picture correctly, you have 40" of coax with the shield removed, then another few inches that retain the shield? I assume the shield portion acts as a "service loop" for the overall installation?

Any feedback on how well it works?

Thanks,
Scott