---------------------------------------------------------- Avionics-List Digest Archive --- Total Messages Posted Sat 09/25/04: 2 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:51 AM - Transponder antenna separation (Roger Evenson) 2. 07:47 AM - Re: Transponder antenna separation (LessDragProd@aol.com) ________________________________ Message 1 _____________________________________ Time: 06:51:54 AM PST US From: "Roger Evenson" Subject: Avionics-List: Transponder antenna separation --> Avionics-List message posted by: "Roger Evenson" Garmin transponder install manual suggests 3' minimum between transponder antenna and any other antenna, and also 3' minimum between transponder antenna and transponder unit itself. I don't have these ideals. I can locate the transponder antenna closer (than 3') to the com antenna in order to be 3' from the transponder itself; or, I can locate the transponder antenna closer to the transponder and maintain 3' between the transponder antenna and the com antenna. Having to compromise, is one criteria more important than the other? ________________________________ Message 2 _____________________________________ Time: 07:47:23 AM PST US From: LessDragProd@aol.com Subject: Re: Avionics-List: Transponder antenna separation --> Avionics-List message posted by: LessDragProd@aol.com Generally, the smaller antenna is blocked by the larger antenna in the direction of the larger antenna. The smaller antenna signal should also be stronger in the opposite direction from the larger antenna. A greater the distance between antennas reduces the signal strength distortion. The larger antenna should be basically unaffected by the smaller antenna, except that the signal could be stronger across the smaller antenna. Hope that helps. Jim Ayers RV-6A mounting transponder antenna in tailcone behind baggage compartment and using a Sportcraft Vertical Stabilizer COM antenna. Just a few holes to patch in the fuselage belly. :-) In a message dated 09/25/2004 6:52:33 AM Pacific Daylight Time, revenson@comcast.net writes: --> Avionics-List message posted by: "Roger Evenson" Garmin transponder install manual suggests 3' minimum between transponder antenna and any other antenna, and also 3' minimum between transponder antenna and transponder unit itself. I don't have these ideals. I can locate the transponder antenna closer (than 3') to the com antenna in order to be 3' from the transponder itself; or, I can locate the transponder antenna closer to the transponder and maintain 3' between the transponder antenna and the com antenna. Having to compromise, is one criteria more important than the other?