Richard

On Sep 23, 8:58*am, Richard wrote:
On Sep 22, 9:47*pm, Darryl Ramm wrote:
[snip]
Darryl,

I agree that the Trig appears to be a nice transpoder and reasonably
priced.

It does not appear to be any easier to install than a Becker or
Microair or have any better specs that the Microair or Becker in a
Mode C environment.

The Trig unit with its two relatively small display/RF units appears
to me to be easier to install in many situations such as with with
tight panel (and behind panel) space and RF cable routing problems
(install the RF box at the antenna). I'm a bit lost as to why you
don't think the Trig has an "easier to install" benefit.


Trig 11min *– 33 max *Volts DC. Typical 5 Watts @ 14Volts.
Is the 11v *acceptable in a Glider?

Apparently yes. These are nominal input voltages. With modern switch
mode power supply technology I'm not so worried about the nominal
lower voltage range. This would be something to check with Trig (I'll
send off an email when I get time). I've not seen any problems
reported by the early users of the Trig TT21 and I would have expected
to from the folks I've been in contact with. Anybody out there had low
voltage issues with the TT21?

Becker 9.5 V to 32.2 V DC
Microair 10v to 33 v * *.15 to .200 amps
Trig *11 to 33 V * .150 to .280 amps (from installation manual)

Low Power Design
The TT21 has one of the lowest power consumptions for any transponder.
With typical power consumption of around 5 watts, it can operate from
battery power for gliders or balloons for long duration flights. In
powered aircraft you can be sure that the TT21 is not making heavy
demands on your electrical system.

5 watts at 12 v = *.41 amps
5 watts at 14v = .35 amps

Where did the .280 amps come from? *I think all the manufactures play
with specifications.

The power requirement comes from the Trig product specs in their
brochure and in their installation manual. Trig states the power
consumption of their TT21 is Idle: 0.15 A Active: 0.28 A, both at 14V.
Remember this includes the internal encoder, the encoder power
consumption for other transponders should be included in any
comparison.

You are trying to compare a very rough "about 5 watts" statement from
the same exact product data sheet as the more detailed specs. When
somebody says "about 5 bananas" Do you assume they have exactly 5.0
bananas, between 4 and 6 bananas, between 1 and 10 bananas? You are
trying to reverse out the typical amperage from the "about 5 watts"
and then slamming them that all this stuff "is played with". They
provide detailed current specs, so be fair and use those.

Transponder power specs are complicated because they depend on
interrogation rate (SSR, TCAS and other) and on the encoder power
consumption that can be fairly temperature dependent (is that Encoder
in a drafty location?). My experience with measuring actual Becker
transponder power consumption is that the specs they provide are very
reasonable. I have not measured other transponders in actual use.
Trig do appear to use a fairly modern, low power encoder. I'd love to
get my hands on a TT21 to do actual power consumption tests. But I
have no reason to believe that the Trig would not be as low a power
consumption as they claim. A very nice thing for sailplane use.

An issue may be the temperature or the glider cockpit. *The Trig
installation manual states * The TT21 is certified to operate
correctly down to -20°C, but at low temperatures the display may be
impaired. On a cold day you may need to wait for the cockpit to warm
up to ensure normal operation.

This is a compete red herring. The LCD displays used on all competing
products will not operate at low temperatures. This is a fundamental
"feature" of LCD display technology. For example the Becker
transponders also spec a minimum operating temperate of -20C. It is
quite likely the LCD display performance sets this lower limit. Kudos
for Trig for clearly explaining this low temperature limit in their
documentation.

All warranties are F.O.B.
Trig Avionics Limited Heriot Watt Research Park Riccarton, Currie,
EH14 4AP
Trig Avionics will not accept or pay for any charges for warranty work
performed outside our factory without prior written consent.

Are you just cut and pasting stuff of the Trig web site or did you
check with their USA distributor?

Southeast Aerospace is the USA distributor. They have publically
stated (see video interview at http://www.youtube.com/watch?v=TAvyjaYzq04)
that during the three year warranty period that warranty repairs are
being handled by field swap of units. With new technolgoy products I
actually think an initial approach of all facory repairs is the right
one. A good warranty period and a distubutor who is stocking spare
units and willing to field swap is a *great* approach. And given what
I think SEAs repair capabilities are it could be that they will do
actual repair in the field in future, I'm not sure. A three year
warranty period is great on new products, I believe both Becker and
Microair transponders have two year warranty period (but the encoder
may have a shorter warranty period - e.g. I believe the ACK A-30 has a
one year warranty, with the Trig TT21 the warranty covers the encoder
as well). Maybe Paul can update his transponder comparison table with
warranty period information.


I perfer not to be a beta tester for a new instrument in the US
airspace environment. TSO only means they have completed the paperwork
requirements. I have experience the early problems with both Becker
and Microair. (They are now both reliable in the US airspace
environment)

Richardwww.craggyaero.com


I've also personally had very good experience with Becker USA service
and would highly recommend Becker because of this. Luckily I never had
any early teething problems with Becker products--the repairs I've
needed were for external damage to a transponder. I had enough bed
experiences with early Microair radios that I never want a Microair
anything in my glider ever. But I do hear that their transponders work
well, and I do occasionally use one in a rental glider. I prefer the
Becker UI however. And I see they went through some problems with
them ultimately requiring airworthiness bulletins. And I believe they
did sorted out their radio problems. The teething and support problems
that Microair had on their VHF radios is absolutely the sort of issues
I would be worried about with adopting *any* new products. So Trig and
SEA has to prove they are up to this. Trig have been shipping the TT31
for several years, mostly in Europe so I'd hope any gross vendor
problems would be visible by now. They also have a good distributor
with SEA in the USA. So purchasers need to make their own decisions,
and the best the rest of us can do is watch reports from early
adopters.

I have no interest in any of these products, resellers etc. My
interest is only in encouraging transponder adoption in areas like
around Reno and other areas of mixed commercial/fast Jet and glider
traffic. I did help Paul Remde with information for the transponder
comparison table on his website at
http://www.cumulus-soaring.com/trans...mparison_Table
to try to explain the different transponder capabilities.


Darryl