cholzer wrote:I recently removed my loran, which was an Azure Long Ranger, portable, with a panel mount tray. Always worked great. The installation instructions stated several times that any antenna should never be mounted within the 'shadow' of another antenna. For instance, if you have an 18 inch comm antenna, no other antenna should be mounted within 18 inches of it, and so forth. Also heard that bit of info from a couple of avionics men at the company. Again, not a hard and fast rule, but good to know.
So, ...three inches from the txdr antnenna?....

(Just kidding, of course.)
Just for edification, here's a clip of the text from the Honeywell Installation Manual for the GPS:
"ANTENNA INSTALLATION CONSIDERATIONS
The antenna should be mounted on top of the fuselage near the cockpit. Avoid mounting the antenna
near any projections, the propeller, and the T-tail of the aircraft, where shadows could occur.
It is recommended that there be a separation of at least 3 ft. between the KLN 90B GPS antenna
and any VHF Comm antenna on the aircraft...."
I managed to obtain a 30-inch distance by mounting it immediately above the cabin instrument/dome lighting, just aft of the cabin speaker and immediately forward of the original factory location of the Narco VOR antenna. The cabin overhead lighting panel was temporarily dropped down to gain access to the antenna connection. It turned out to be an ideal location, very easy to access. I ran the ant. cable above the headliner toward the left fuel gauge, then into the wing-root area (above that flat wing-root fairing, then forward to the left/fwd door-post, and then down inside the door-post and side-panel to the GPS receiver.
I've made the first flight with it to the Lockhart fly in, and it works perfectly. (Well, except for the error MSG warning "No Altitude Data" available. I've got 1N4007 isolation diodes ordered from Allied Electronics* for installation per the manual between the txdr and the encoder, then I'll patch the KLN-90B into the data cable between encoder/txdr. (This GPS uses encoder altitude data to meet VNAV requirements for SIDS/STARS and it also functions as an altitude-alerter if desired...I haven't yet decided if I want that feature or not. I'm afraid it'll just become a nuisance to me, and I'd have to install a Sonalert and alt-warn lamp, and also wire it into my headset/audio-panel to make full use of the altitude-alert feature.)
* Allied Electronics is a supplier of components who, not only has an actual store location but, will accept online orders. I could not believe Radio Shack does not handle a wide assortment of diodes anymore. They carry 1N4004 but not 1N4007 diodes, and although the 1N4004 would probably be just fine, it is not exactly as specified for lightning protection per Honeywell. RS wants $3 each for those diodes, and I need 8 of them. Allied gets 3-CENTS each for the correct 1N4007 and so I ordered a dozen (40-cents)... Of course handling is $5

and U.S. mail is $4

....but that's less expensive than driving to Austin and back so can live with it.
http://www.alliedelec.com