On Mon, 28 Apr 2008 19:20:20 GMT, Tauno Voipio
wrote in
:

Larry Dighera wrote:
radar energy as aluminum.

The issue in equipping gliders with transponders, the way I see it, is
the high power consumption required by transponders. Here's a typical
glider transponder: http://www.airplanegear.com/becker.htm
It seems to draw 175W to 250W. That's not insignificant, and way more
than the comm radio consumes. Then there's the weight and antenna
that reduce performance, not to mention the cost of the equipment,
installation, and maintenance.


You may have made a small mistake: 175 to 250 Watts
is the pulse output power. In the same document, the
current consumption is about a half ampere at 14 V,
which is 7 Watts.

You are correct. Here's another with even less power consumption:
http://www.sportflyingshop.com/Avion...ansponder.html
Microair T2000 Transponder, $1,825
Wiring harness for T2000, $149
Ameri-King AK-350 Blind Encoder, $179

Power input: .25 amps @ 27.50 volts;
.4 amps @ 13.75 volts TX,
80 mA RX

I wonder if those power consumption figures include the heater in the
encoder.


Perhaps it's a good idea to require equipping all gliders with
transponders after all. :-(