Transponder pictures.

[Phil_P]

I'm currently working on a transponder installation. Living and flying as I do on the edge of the Lincs. AIAA with RAF Tornados coming over my house quite regularly at between 200 and 500 feet, I have absolutely no desire to have a close encounter of the afterburner kind.

The installation is based around a Becker remote head transponder with an AmeriKing altitude encoder that will provide mode C altitude reporting. The whole kit is very compact and light. I intend powering it from a 4 cell lithium polymer battery, giving 14.8v and 3000mAh. Current drain is only about 600mA except when being interrogated, at which time it rises to about 1.5A (but this is for a very short duty cycle). I am working on getting about 5 hours use from a full charge.

The main unit, encoder and batteries will be housed in a 'Pelican' waterproof case which will hang from the side of the harness, or alternatively into the underseat compartment. The remote head will mount so that I have easy access in flight.

The current antenna mounting is to an alloy plate, pop-riveted to the top of the cage. Although there is a school of thought that thinks the high power microwave output (250 watts on this unit) poses a health risk, when the figures are analysed it would seem that worries are exaggerated, at least I'm quite happy. The mounting will put about 24 inches between the antenna and the closest part of my anatomy (my head) and a substantial distance from my nether regions.

For those interested enough to have got this far, if you want to have a look at some pictures, click here;

http://s34.photobucket.com/albums/d139/ ... mview=grid