On Jun 22, 7:32*am, kd6veb wrote:
* The Zaon PCAS unit which is the size of a cigarette pack contains an
accurate pressure encoder plus almost all the electronics needed for a
transponder at a street price less than $500. What it does not have is
the high power transmitter. So I called the Zaon technical people and
suggested had they ever considered making an inexpensive, low power,
single unit tiny in size transponder. Their response was not seriously
because of the certification process but they would consider what I
suggested.
* The bottom line to this is that the technology is available to make
a tiny inexpensive fully featured transponder and sell it for less
than a $1,000. Will it happen? Probably not. A couple more people from
the glider community talking to Zaon might be useful.
* Zaon has almost the total market for PCAS deservedly because of
their 2 excellent products. They must be thinking of an encore.
How about a transponder?
Dave

PS There is not technical reason for a 2 piece transponder and the new
one discussed in this thread, in my opinion, still has not got it
right.

I'll bite.

There are RF engineering reasons why it will be harder to put a PCAS
and Transponder in the same box. Zaon would an uphill battle already
enterign the transponder market for light aircraft with Becker and
others and now Trig with some pretty nice transponders. Zaon does low-
end traffic avoidance, they need to be focused on keeping there
leadership there. with ADS-B (Both UAT and 1090ES) is the future of
traffic avoidance in the GA fleet and that is where Zaon should be
spending there time. I'd hope they are working on a combined PCAS+UAT
(data in only) device. Otherwise devices like the NavWorx PADS600 will
take that market away from Zaon as ADS-B starts being adopted.

There are often great reasons for a two box transponder. Including
being able to mount the RF box nearer the antenna and simplify cabling
and save RF power loss as the previous owner mentioned. However with
the need to plumb the transponder to a static line there may be
tradeoffs between static line and coaxial cable routing. You also get
to avoid RF coax cable flex and damage with gliders with front hinged
panels. The compact control head allows mounting in shallow panels,
takes weight off the panel mount screws etc.

The Trig TT21 RF box is also significantly smaller than other two box
or single box transponders. e.g. the TT21 RF box is 5.6" x 2.4" x
1.8". A normal Becker Mode-S panel mount is 8.0" x 2.4" x 2.4" and a
remote mount box is 8.5" x 2.4" x 2.4". That makes it easier to mount
in many remote locations.

The only nits I have to pick withe TT21 is it does not appear to allow
tandem installation (dual control heads), and as mentioned easier it
supports ADS-B 1090ES out but not in. But (I forgot to mention this
earlier) there is a tantalizing RS-232 port for "future upgrades". Mmm
I wonder if that could be for ADS-B TIS-B out. Either way, given its
price and size and other things if it works as claimed and is reliable
it looks to me like a winner.

Darryl