In article "Morgans" writes:
"Peter Dohm" wrote

I 'm confident that the installation is the biggest part of it--especially
when you include enough solar panels to power it all reliably.

Why solar cells? A 7 amp hour lead acid gel cell can be had for about 20 bucks,
and would run a solid state transponder for a whole flight.

One doesn't want to run the lead acid battery down past about 1/2 its capacity
to get a reasonable service life from it, so that limits you to 3.5 AH.

Given that they are also probably running some of:

o A com radio.
o An elecronic variometer.
o A gps.
o A flight logger.

and that they are wanting these to run for flights of 5 - 8 hours or more,
it is fairly clear that the 7 AH battery cannot do it.

I would expect they have already trimmed the list of electronic items
in order to get their flight time from the battery, so a transponder would
need another battery, or giving up some of the other equipment.


More thoughts on the basic issue of protecting IFR aircraft from gliders.
How about designating that area as having fairly low speed limits all the
way up to 18,000 feet (where wave windows would take over for separation),
only in this case note that if the aircraft is unable to fly that slowly,
they have to go around the airspace.


Alan