Bob Archer Nav Antenna install?
 

I have an Archer Nav antenna and I know that Bob's instructions are to mount it at the front of the wing tip and run the lighting wires along the front edge of the antenna. What I don't understand is why run the lighting wires on the antenna at all?

There's plenty of room in the wing tip to mount the nav antenna in the aft half of the tip - which would keep the antenna and lighting wires totally separate. I sent a couple of emails to Bob, but never got a reply.

By running the wires along the edge they effectively become part of the antenna.

By moving them 6" or so away from the antenna they will interfere with signal strength in some orientations relative to the ground station.

Rick, since you and I are both building a 7, here is what I did also. Sorry Dan, I posted this without your permission:-) Anyway, my antenna is well aft of the the tip position/strobe lights so mine looks just like Dan's install.

http://www.rvproject.com/20040128.html

That's what I had in mind.
 

Dana, that just what I was thinking about doing - except on the bottom. Even on the bottom there is a good 12" or more of separation between the lighting wires and VOR antenna. I'd be interested to hear from Dan about how his installation works while flying (or anyone else that installed it like Dan).

Archer Nav antenna
 

Does anyone know why the Nav antenna goes on the top of the tip? Wouldn't the antenna "see" the VOR site better from the bottom of the tip without the wing partially shielding the antenna?

Not sure of the exact shape of your wingtips, but on my RV-6 the top of the tip allowed the antenna to be mounted very close to "horizontal". The antenna needs to be as close to horizontal as possible since the NAV signals are likewise horizontally polarized.

The antenna won't have any problems "seeing" the NAV signals even though it is behind the wing structure. I can't 'plain, it, only know that it works: :)

http://thervjournal.com/sportcraft.htm

RF black magic
 

Rick... the usual standard is to keep obstructions a quarter wavelength away from an antenna.

For the VOR this is in the order of 22 inches or so. 12 inches separation is a bit too close.

Of course, all of this antenna theory is black magic.... :D
Some installation might work, and other similar looking ones won't.
Given a choice, it's probably best to stick to the standard (and what the magician says .... :) ....) in this case...

gil in Tucson - preferring digital signals to RF... :)

I actually think I mounted mine on the bottom of the wing tips....but everything was upside down at one time or another, and I can't be sure....the VOR/LOC/GS work fine, in any case!

Paul

Does anyone know if Bob Archer still sells his antennas directly? I can't find an email address for him that works.

(Garmin SL-30 just arrived, I need to feed it!)

Larry

Where to buy
 

Bob Archer
21818 Ocean Ave.
Torrance CA
90503
Phone 310-316-8796

bobsantenna@earthlink.net

$70 each plus $8 ship Dec 2006