New Transponder for us

[Ernst]

Is this an alternative?
http://www.sandia.aero/?q=STX165

[Paul Remde]

Hi,

The Trig TT21 and TT21 are similarly priced (a little more expensive) but
has proven to be a fantastic product. Also, its control head fits into a 57
mm instrument hole, or a smaller hole.

It would be interesting to compare the current draw of the 2 brands. I'd be
surprised if the Sandia unit uses less power than the Trig TT21.

Best Regards,

Paul Remde
Cumulus Soaring, Inc.

"Ernst" > wrote in message
...
> Is this an alternative?
> http://www.sandia.aero/?q=STX165

[Richard[_9_]]

On Dec 8, 10:24*am, Ernst > wrote:
> Is this an alternative?http://www.sandia.aero/?q=STX165

Ernst,

Other than it is square, it looks like a good option.

Craggy Aero will be selling them. They will probably be available
around 2/1/2011 and will be priced less than $1700.

Specs look similar to the higher powered Trig and it really is a one
piece transponder.

Thanks,

Richard
www.craggyaero.com

[Andy[_1_]]

On Dec 8, 11:24*am, Ernst > wrote:
> Is this an alternative?http://www.sandia.aero/?q=STX165

Why would anyone buy a mode C transponder when for only a little more
one can buy a mode S unit?

Andy

[Darryl Ramm]

On Dec 8, 11:21*am, Richard > wrote:
> On Dec 8, 10:24*am, Ernst > wrote:
>
> > Is this an alternative?http://www.sandia.aero/?q=STX165
>
> Ernst,
>
> Other than it is square, it looks like a good option.
>
> Craggy Aero will be selling them. *They will probably be available
> around 2/1/2011 and will be priced less than $1700.
>
> Specs look similar to the higher powered Trig and it really is a one
> piece transponder.
>
> Thanks,
>
> Richardwww.craggyaero.com

OK I'll play this game. The specs look *nothing* like the Trig TT21/22
starting with...

1. This is a Mode C not a Mode S transponder.

2. The brochure lists 500mA power consumption at 28VDC. Assuming
perfect power supply behavior that translates to 1.1 A current draw at
12VDC. That is more than the total power consumption of many gliders.
A Trig TT-21 in a test righ being hammered with a high rate of
interrogations (similar to the rate used in the specs of the
transponder here) measured 325mA @ 12VDC. In practice owners of the
TT21 are seeing power consumption below 300mA. Richard this can't
possibly be right or the transponder will be utterly useless in
gliders - since you are planning on selling them what is the correct
power consumption at 12VDC.

3. They claim this is targeted at gliders and others uses, yet they
picked a mounting rectangular mount form factor pretty incompatible
with the standard 57mm hole (The Trig TT21 uses that hole or a smaller
rectangular cutout) the transponder mention here is a huge 1.78”H x
3.5”W (case dimension, panel cutout smaller).

---

Hang on, I feel it coming,...

WHAT THE !@#$? A $%^ DAMN BLOODY BOAT ANCHOR PIECE OF CRAP MODE C
TRANSPONDER!

(phew, now I fell better).

Why would any company in their right mind start building Mode C
transponders in the age of ADS-B data-out mandates in the USA? And
Mode S mandates in place already in Europe? Why would any purchaser in
their right mind purchase and install a Mode C transponder when the
Mode S Trig TT21 is available, is smaller, uses less power, is well
proven (good adoption esp. in gliders, used by the FAA for ADS-B
surveys, OEM'ed by Dynon, etc.) and provides a path to do 1090ES data-
out. Especially for the glider owners interested in a PowerFLARM the
Trig TT21 is currently by far the best option. There are other compact
affordable Mode S transponder options in Europe but none others
available in the USA at the current time. Maybe that will change over
time, competition is a nice thing.

The USA Mode C transponder market deserves to go away and die. If
(like me) you have one now it will keep working find and doing great
stuff for visibility to ATC and TCAS etc. for the foreseeable future
but it gives you no ADS-B data-out option. And specifically does not
give you 1090ES data-out that gives you direct long-range (much longer
then PowerFLARM-PowerFLARM) visibility to PowerFLARM receivers or
allow use with PowerFLARM for receiving ADS-R and TIS-B services.

There is absolutely space to argue that UAT devices can be used to do
ADS-B data-out to add to existing Mode C equipped aircraft (especially
for power aircraft to meet the 2020 carriage mandate) but I see no
justification for purchasing new Mode C transponders when there are
well priced and much more competitive Mode S transponders available
that provide that ADS-B data-out path (and in this case are much more
compact, easier to mount and appear to consume a lot less power).

Darryl

[jcarlyle]

For two reasons: (1) it costs less to perform the biannual
inspection, and (2) you aren't broadcasting your tail number to the
Feds. Of course, you'll only get a 10 year life out of it...

-John

On Dec 8, 2:54 pm, Andy > wrote:
> Why would anyone buy a mode C transponder when for only a little more
> one can buy a mode S unit?
>
> Andy

[Darryl Ramm]

On Dec 8, 12:03*pm, jcarlyle > wrote:
> For two reasons: *(1) it costs less to perform the biannual
> inspection, and (2) you aren't broadcasting your tail number to the
> Feds. Of course, you'll only get a 10 year life out of it...
>
> -John
>
> On Dec 8, 2:54 pm, Andy > wrote:
>
> > Why would anyone buy a mode C transponder when for only a little more
> > one can buy a mode S unit?
>
> > Andy
>
>


Actually the 10 year life is not completely accurate, even if I agree
a bit with probably the sentiment behind it. I just don't want any
glider pilots with Mode C transponders to think their transponders
have an abslute hard limit where they stop being useful in 10 years.

Mode C transponders are usable it the USA well beyond 10 years - but
to meet the 2020 ADS-B data-out carriage requirement (a requirement
for power aircraft in similar airspace as transponders are required
now) you would need to add a UAT transmitter or replace the
transponder with a Mode S with 1090ES data-out. Right now its
impractical from a cost, STC paperwork hassle (on non-experimental)
and final -B rev compliance requirements on many products, to add ADS-
B data-out to most light aircraft or gliders but you can install a
Trig TT21 and in future update the firmware and add the ADS-B data-out
GPS.

How current aircraft owners manage the transition to the 2020 ADS-B
data-out mandate will be interesting to see - i.e. whether Mode C
equipped aircraft add UAT devices or swap out their transponders to
get new Mode S units with 1090ES data-out. I expect many will take the
transponder upgrade route since it is a chance to refresh older
transponders which they still need to carry (in may owner aircraft)
and older transponders can become a maintenance liability, so why not
refresh both in one box? For newer Mode C transponders there exists
more of an argument to add a UAT device. In the glider community in
the USA with PowerFLARM looking like important and popular technology
Mode S 1090ES data-out is a better technology to consider than UAT
data-out.

Darryl

[Andy[_1_]]

On Dec 8, 1:03*pm, jcarlyle > wrote:
> For two reasons: *(1) it costs less to perform the biannual
> inspection, and (2) you aren't broadcasting your tail number to the
> Feds.

Ok, valid points.

I just checked with my local avionics shop. $95 for mode C and $125
for mode S. Not a deal breaker for me.

As to broadcasting the tail number - the TT21 installation menus
allow the aircraft ICAO code and the registration to be set but I
don't think there is an equipment requirement for them to be set. In
other words I think it will work if the defaults are left unchanged.
Is there any regulation that requires a mode S transponder to transmit
that data in US?

Andy

[Darryl Ramm]

On Dec 8, 12:37*pm, Andy > wrote:
> On Dec 8, 1:03*pm, jcarlyle > wrote:
>
> > For two reasons: *(1) it costs less to perform the biannual
> > inspection, and (2) you aren't broadcasting your tail number to the
> > Feds.
>
> Ok, valid points.
>
> I just checked with my local avionics shop. $95 for mode C and $125
> for mode S. Not a deal breaker for me.
>
> As to broadcasting the tail number *- the TT21 installation menus
> allow the aircraft ICAO code and the registration to be set but I
> don't think there is an equipment requirement for them to be set. *In
> other words I think it will work if the defaults are left unchanged.
> Is there any regulation that requires a mode S transponder to transmit
> that data in US?
>
> Andy

A Mode S transponder absolutely has to transmit the aircraft ICAO
address, a correctly configured ICAO address is required for the
transponder to actually work--bad things might happen if two aircraft
had the same default ICAO address were being interrogated at the same
time.

I am not sure where else this is captured in the regulations, but
checking this is a requirement at install and during the biannual
"Part 43 Appendix F" test.

Part 43 Appendix F...

(f) Mode S Address: Interrogate the Mode S transponder and verify that
it replies only to its assigned address. Use the correct address and
at least two incorrect addresses. The interrogations should be made at
a nominal rate of 50 interrogations per second.

---

I can't find it quickly in the regs but it may just be that the
requirement in 14CFR 91.215 (b) to operate in compliance with TSO
C-112 (which then captures you the pilot and not just the manufacturer
and that TSO's incorporation of RTCA DO-181 which may spell out the
Mode S address requirement). There better be an overriding
requirement, otherwise somebody could argue a pilot can can just
change it at any time. Yes its the off season but I'm not so bored yet
to fully follow this though.

Please be very careful here. Make sure your Mode S transponder is
using the correct ICAO address (the one registered to your aircraft).
If you really think you are goign to be doing bad things within view
of ATC then maybe you should rethink how you are flying.

Darryl

[jcarlyle]

What Darryl said.

You might like to know that the avionics technician who did my VFR
transponder checks went to his computer and got the proper ICAO code
from the FAA. The reason is the "S" in Mode S stands for selective,
and they want to be darn sure ATC is broadcasting to the proper
aircraft.

I was being tongue in cheek with my previous post. There's no reason,
given the price and low power draw of the Trig TT21, that anyone
should even consider buying anything else right now (unless they're
replacing an existing transponder with the same type).

-John

On Dec 8, 3:37 pm, Andy > wrote:
> As to broadcasting the tail number - the TT21 installation menus
> allow the aircraft ICAO code and the registration to be set but I
> don't think there is an equipment requirement for them to be set. In
> other words I think it will work if the defaults are left unchanged.
> Is there any regulation that requires a mode S transponder to transmit
> that data in US?

[Andy[_1_]]

On Dec 8, 2:48*pm, jcarlyle > wrote:
> What Darryl said.
>
> You might like to know that the avionics technician who did my VFR
> transponder checks went to his computer and got the proper ICAO code
> from the FAA. The reason is the "S" in Mode S stands for selective,
> and they want to be darn sure ATC is broadcasting to the proper
> aircraft.

All seems very reasonable and I would have no intention of using an
incorrect ICAO address. Did your technician also check that the
transmitted registration number, which seems to be a separate data
entry on the TT21, was correct?

Andy

[jcarlyle]

Yes, he did.

-John

On Dec 8, 5:38 pm, Andy > wrote:
> All seems very reasonable and I would have no intention of using an
> incorrect ICAO address. Did your technician also check that the
> transmitted registration number, which seems to be a separate data
> entry on the TT21, was correct?
>
> Andy

[Dave Nadler]

On Dec 9, 7:18*am, Darryl Ramm > wrote:
> On Dec 8, 12:03*pm, jcarlyle > wrote:
>
> > For two reasons: *(1) it costs less to perform the biannual
> > inspection, and (2) you aren't broadcasting your tail number to the
> > Feds. Of course, you'll only get a 10 year life out of it...
>
> > -John
>
> > On Dec 8, 2:54 pm, Andy > wrote:
>
> > > Why would anyone buy a mode C transponder when for only a little more
> > > one can buy a mode S unit?
>
> > > Andy
>
> Actually the 10 year life is not completely accurate, even if I agree
> a bit with probably the sentiment behind it. I just don't want any
> glider pilots with Mode C transponders to think their transponders
> have an abslute hard limit where they stop being useful in 10 years.
>
> Mode C transponders are usable it the USA well beyond 10 years - but
> to meet the 2020 ADS-B data-out carriage requirement (a requirement
> for power aircraft in similar airspace as transponders are required
> now) you would need to add a UAT transmitter or replace the
> transponder with a Mode S with 1090ES data-out. Right now its
> impractical from a cost, STC paperwork hassle (on non-experimental)
> and final -B rev compliance requirements on many products, to add ADS-
> B data-out to most light aircraft or gliders but you can install a
> Trig TT21 and in future update the firmware and add the ADS-B data-out
> GPS.
>
> How current aircraft owners manage the transition to the 2020 ADS-B
> data-out mandate will be interesting to see - i.e. whether Mode C
> equipped aircraft add UAT devices or swap out their transponders to
> get new Mode S units with 1090ES data-out. I expect many will take the
> transponder upgrade route since it is a chance to refresh older
> transponders which they still need to carry (in may owner aircraft)
> and older transponders can become a maintenance liability, so why not
> refresh both in one box? For newer Mode C transponders there exists
> more of an argument to add a UAT device. In the glider community in
> the USA with PowerFLARM looking like important and popular technology
> Mode S 1090ES data-out is a better technology to consider than UAT
> data-out.
>
> Darryl

Don't forget, mode S will use a lot less power
under non-trivial interrogation...
From soggy Oz,
]See ya, Dave

[Darryl Ramm]

On Dec 8, 4:18*pm, Dave Nadler > wrote:
> On Dec 9, 7:18*am, Darryl Ramm > wrote:
>
>
>
> > On Dec 8, 12:03*pm, jcarlyle > wrote:
>
> > > For two reasons: *(1) it costs less to perform the biannual
> > > inspection, and (2) you aren't broadcasting your tail number to the
> > > Feds. Of course, you'll only get a 10 year life out of it...
>
> > > -John
>
> > > On Dec 8, 2:54 pm, Andy > wrote:
>
> > > > Why would anyone buy a mode C transponder when for only a little more
> > > > one can buy a mode S unit?
>
> > > > Andy
>
> > Actually the 10 year life is not completely accurate, even if I agree
> > a bit with probably the sentiment behind it. I just don't want any
> > glider pilots with Mode C transponders to think their transponders
> > have an abslute hard limit where they stop being useful in 10 years.
>
> > Mode C transponders are usable it the USA well beyond 10 years - but
> > to meet the 2020 ADS-B data-out carriage requirement (a requirement
> > for power aircraft in similar airspace as transponders are required
> > now) you would need to add a UAT transmitter or replace the
> > transponder with a Mode S with 1090ES data-out. Right now its
> > impractical from a cost, STC paperwork hassle (on non-experimental)
> > and final -B rev compliance requirements on many products, to add ADS-
> > B data-out to most light aircraft or gliders but you can install a
> > Trig TT21 and in future update the firmware and add the ADS-B data-out
> > GPS.
>
> > How current aircraft owners manage the transition to the 2020 ADS-B
> > data-out mandate will be interesting to see - i.e. whether Mode C
> > equipped aircraft add UAT devices or swap out their transponders to
> > get new Mode S units with 1090ES data-out. I expect many will take the
> > transponder upgrade route since it is a chance to refresh older
> > transponders which they still need to carry (in may owner aircraft)
> > and older transponders can become a maintenance liability, so why not
> > refresh both in one box? For newer Mode C transponders there exists
> > more of an argument to add a UAT device. In the glider community in
> > the USA with PowerFLARM looking like important and popular technology
> > Mode S 1090ES data-out is a better technology to consider than UAT
> > data-out.
>
> > Darryl
>
> Don't forget, mode S will use a lot less power
> under non-trivial interrogation...
> From soggy Oz,
> ]See ya, Dave

Dave is correct that Mode S transponders will consume less power in
some environments where they are being interrogated as a Mode S
transponder since they do not see the extra Mode A/C interrogations
(at least not those from a Mode S capable interrogator) and so need to
transmit fewer replies than a Mode C transponder. However that does
*not* get close to explaining the apparent high power consumption
(>1.1 Amp!!) of this Mode C transponder vs. the Trig Mode S
transponder.

The exact details of power consumption in different situations for SSR
radar depends on details of the ATCRBS ground interrogator. The
transponder will still likely get hit by multiple interrogations per
sweep and the individual transmission from the Mode S transponder may
well take more power than that a Mode C transmission. The power
required for a Mode A/C transmission depends on the squawk code
(==pulse pattern) but the power required for the Mode S data-packet
does not change like this.

In complex TCAS I and II environments the Mode S transponder will see
fewer interrogations but even a Mode C transponder will only reply to
a small fraction of the realtively high interrogation rate of a TCAS
system since TCAS uses the "whisper-shout" trick to cause Mode C
transponders within a certain distance range to reply. Its all that
TCAS Mode C interrogation and replies from some of the Mode C
transponders that is a bandwidth hog (and why goign to Mode S only in
the USA might have been a good idea to support ADS-B 1090ES). Mode S
is much more elegant. TCAS discovers the Mode S transponder by its
acquisition squitter (advertising it is there without needing to be
interrogated) and the TCAS interrogator can interrogate Mode S
transponders uniquely without using the whisper-shout hack.

If being interrogated by a Mode C only interrogator (e.g. by GA
aircraftTCAD/TAS systems (which have traditionally not supported Mode
S interrogations) then the Mode S transponder will transmit Mode A/C
replies without any of the Mode S stuff.

Darryl

[Eric Greenwell[_4_]]

On 12/8/2010 4:51 PM, Darryl Ramm wrote:
> However that does
> *not* get close to explaining the apparent high power consumption
> (>1.1 Amp!!) of this Mode C transponder vs. the Trig Mode S
> transponder.

According to the brochure I downloaded, the remote version of the unit
only requires 200 ma, instead of 500 (still at 28 volts). That's still
pretty high for a version without the encoder, but it makes me wonder
where the 300 ma is going.

Someone could call the company to find out, but really, I see little
value in it when the Trig is so good. If you want to save some money,
offer to buy a used Becker for, say, $1000-$1200, and get one from
someone that's thinking of upgrading to a Trig.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)

[Grider Pirate]

> Someone could call the company to find out, but really, I see little
> value in it when the Trig is so good. If you want to save some money,
> offer to buy a used Becker for, say, $1000-$1200, and get one from
> someone that's thinking of upgrading to a Trig.
>
I'm just waiting for Trig to produce a transceiver too.

[Darryl Ramm]

On Dec 8, 6:59*pm, Eric Greenwell > wrote:
> On 12/8/2010 4:51 PM, Darryl Ramm wrote:
>
> > However that does
> > *not* get close to explaining the apparent high power consumption
> > (>1.1 Amp!!) of this Mode C transponder vs. the Trig Mode S
> > transponder.
>
> According to the brochure I downloaded, the remote version of the unit
> only requires 200 ma, instead of 500 (still at 28 volts). That's still
> pretty high for a version without the encoder, but it makes me wonder
> where the 300 ma is going.
>
> Someone could call the company to find out, but really, I see little
> value in it when the Trig is so good. If you want to save some money,
> offer to buy a used Becker for, say, $1000-$1200, and get one from
> someone that's thinking of upgrading to a Trig.
>
> --
> Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
> email me)

Either Sandia is quoting numbers for an encoder with heater full on
(unusual to do so), or they have an inefficient encoder design or
their control head draws a surprising large amount of power (for
something with an OLED display), or some combination of all of that.

A good rough number for steady state consumption for an ACK-30 encoder
(what most of us with Mode C transponders in gliders use today) is a
bit over 60mA @ 12VDC without the heater on. Heater full on they can
draw >400mA @ 12VDC (luckily the heater should not be on often in
usual use - but if you are flying in wave especially make sure the
encoder box is insulated and protected from drafts).

But even then even if you were compete nuts and wanted to spend money
on a Mode C transponder today the headless version of this transponder
is still not an option until somebody has a controller that can
control it.

BTW the heater in the encoder built into the Trig TT21/22 kicks in
starting at 4C down to -25C where it is full on. At its peak it
consumes 1.7 Watts (= 140mA @ 12VDC). Very impressive numbers. Data is
from Trig engineering.

I have a pair of very nice electrical heated boot insoles that I
brought for wave flying and they consume almost the same as the spec
on this Sandia transponder implies it does at 12VDC. Possible since I
have 2 x 18Ah batteries, a engine driven generator, and a large solar
panel in my motor glider... but still if I'm going to just absolutely
burn power for the hell of it its going to be for important stuff like
keeping my feet warm not to run this junk.

Darryl

[Richard[_9_]]

On Dec 8, 1:48*pm, jcarlyle > wrote:
> What Darryl said.
>
> You might like to know that the avionics technician who did my VFR
> transponder checks went to his computer and got the proper ICAO code
> from the FAA. The reason is the "S" in Mode S stands for selective,
> and they want to be darn sure ATC is broadcasting to the proper
> aircraft.
>
> I was being tongue in cheek with my previous post. There's no reason,
> given the price and low power draw of the Trig TT21, that anyone
> should even consider buying anything else right now (unless they're
> replacing an existing transponder with the same type).
>
> -John
>
> On Dec 8, 3:37 pm, Andy > wrote:
>
>
>
> > As to broadcasting the tail number *- the TT21 installation menus
> > allow the aircraft ICAO code and the registration to be set but I
> > don't think there is an equipment requirement for them to be set. *In
> > other words I think it will work if the defaults are left unchanged.
> > Is there any regulation that requires a mode S transponder to transmit
> > that data in US?- Hide quoted text -
>
> - Show quoted text -

Price is the reason $400 to $500 less than the Trig Mode C.

Richard
www.craggyaero.com

[Darryl Ramm]

On Dec 9, 7:38*am, Richard > wrote:
> On Dec 8, 1:48*pm, jcarlyle > wrote:
>
>
>
> > What Darryl said.
>
> > You might like to know that the avionics technician who did my VFR
> > transponder checks went to his computer and got the proper ICAO code
> > from the FAA. The reason is the "S" in Mode S stands for selective,
> > and they want to be darn sure ATC is broadcasting to the proper
> > aircraft.
>
> > I was being tongue in cheek with my previous post. There's no reason,
> > given the price and low power draw of the Trig TT21, that anyone
> > should even consider buying anything else right now (unless they're
> > replacing an existing transponder with the same type).
>
> > -John
>
> > On Dec 8, 3:37 pm, Andy > wrote:
>
> > > As to broadcasting the tail number *- the TT21 installation menus
> > > allow the aircraft ICAO code and the registration to be set but I
> > > don't think there is an equipment requirement for them to be set. *In
> > > other words I think it will work if the defaults are left unchanged.
> > > Is there any regulation that requires a mode S transponder to transmit
> > > that data in US?- Hide quoted text -
>
> > - Show quoted text -
>
> Price is the reason *$400 to $500 less than the Trig Mode C.
>
> Richardwww.craggyaero.com

Trig does not make a "Mode C" transponder.

Darryl

[Richard[_9_]]

On Dec 9, 7:46*am, Darryl Ramm > wrote:
> On Dec 9, 7:38*am, Richard > wrote:
>
>
>
>
>
> > On Dec 8, 1:48*pm, jcarlyle > wrote:
>
> > > What Darryl said.
>
> > > You might like to know that the avionics technician who did my VFR
> > > transponder checks went to his computer and got the proper ICAO code
> > > from the FAA. The reason is the "S" in Mode S stands for selective,
> > > and they want to be darn sure ATC is broadcasting to the proper
> > > aircraft.
>
> > > I was being tongue in cheek with my previous post. There's no reason,
> > > given the price and low power draw of the Trig TT21, that anyone
> > > should even consider buying anything else right now (unless they're
> > > replacing an existing transponder with the same type).
>
> > > -John
>
> > > On Dec 8, 3:37 pm, Andy > wrote:
>
> > > > As to broadcasting the tail number *- the TT21 installation menus
> > > > allow the aircraft ICAO code and the registration to be set but I
> > > > don't think there is an equipment requirement for them to be set. *In
> > > > other words I think it will work if the defaults are left unchanged..
> > > > Is there any regulation that requires a mode S transponder to transmit
> > > > that data in US?- Hide quoted text -
>
> > > - Show quoted text -
>
> > Price is the reason *$400 to $500 less than the Trig Mode C.
>
> > Richardwww.craggyaero.com
>
> Trig does not make a "Mode C" transponder.
>
> Darryl- Hide quoted text -
>
> - Show quoted text -

Sorry I agree on the Mode S tell the other vendor to correct his web
site.

Trig TT21 Class 2 Mode C Transponder with Built-in Altitude Encoder
$2095

If you compare to the 35,000' $700 to $800 Less


Richard
www.craggyaero.com

[Mike Ash]

In article
>,
Darryl Ramm > wrote:

> A good rough number for steady state consumption for an ACK-30 encoder
> (what most of us with Mode C transponders in gliders use today) is a
> bit over 60mA @ 12VDC without the heater on. Heater full on they can
> draw >400mA @ 12VDC (luckily the heater should not be on often in
> usual use - but if you are flying in wave especially make sure the
> encoder box is insulated and protected from drafts).

Pardon me for hijacking the thread, but this suddenly made me realize
that I've been wondering about these encoders for a while.

This is probably obvious to those in the know, but alas, it's not coming
to me. Why is it that a transponder encoder requires a heater, when a
mechanical altimeter functions just fine on its own?

--
Mike Ash
Radio Free Earth
Broadcasting from our climate-controlled studios deep inside the Moon

[Andy[_1_]]

On Dec 9, 8:58*am, Richard > wrote:
> Trig TT21 Class 2 Mode C Transponder with Built-in Altitude Encoder
> $2095
>
> If you compare to the 35,000' * * * $700 to $800 Less

Right, but you can buy the TT21 for a lot less than that if you shop
around. Trig has a minimum advertised retail price policy but some
vendors are selling much lower. It's the old "put one in the order
basket to see the real price" trick.

Check Aircraft Spruce as an example.

Andy

[Darryl Ramm]

On Dec 9, 8:22*am, Andy > wrote:
> On Dec 9, 8:58*am, Richard > wrote:
>
> > Trig TT21 Class 2 Mode C Transponder with Built-in Altitude Encoder
> > $2095
>
> > If you compare to the 35,000' * * * $700 to $800 Less
>
> Right, but you can buy the TT21 for a lot less than that if you shop
> around. *Trig has a minimum advertised retail price policy but some
> vendors are selling much lower. *It's the old "put one in the order
> basket to see the real price" trick.
>
> Check Aircraft Spruce as an example.
>
> Andy


Richard

You seem to be referring to this page http://www.cumulus-soaring.com/trig.htm
I expect Paul will have the "Mode C" typo fixed asap, but the same
page has lots of information on the Trig TT21/22 making clear they are
Mode S transponder.

---

There are at least three USA glider dealers actively selling the Trig
TT21.

Cumulus Soaring - http://www.cumulus-soaring.com/trig.htm
Williams Soaring - http://www.williamssoaring.com/catalog/index.html
(a dealer but no Trig info on their web store yet)
Wings and Wheels -
http://www.wingsandwheels.com/Transponders%20encoders%20PCAS%20MRX%20XRX%20TTPAS %20Becker%20TRIG%20Microair.htm

And Tim there is advertising this new Sandia transponder as well. Jeez
Tim! Maybe Tim or Richard can clarify the actual 12 VDC power
consumption of the Sandia transponder.

I understand the USA Trig distributor wanted higher upfront commitment
from the channel than other distributors and that may be a reason why
fewer dealers are carrying them than other brands. I don't know why
Craggy Aero does not sell the Trig transponders. It would seems a very
natural fit for the PowerFLARM that Craggy Aero has been doing a great
job promoting.

As for the relative cost. Most glider pilots do just fine installing a
lower cost and lower power consumption 125W transponder (whether a new
Trig TT21 or the Becker ATC-4401-175 many of us use). So for new
transponders for gliders in the USA any price comparison really should
be against the street price of a TT21. It really is irrelevant that
the Sandia is a 200W transponder, that does not justify a price
comparison to a Trig TT22 200W transponder. And as others have pointed
out we need to be a little careful comparing advertised and actual
street prices.

It is great to see pilots using a transponder (any transponder) where
we have high density airliner and fast jet traffic etc. and a Mode S
or Mode C transponder works well there today (but its the long term
ADS-B future where a Mode S shines). But I'd hate to see glider pilots
not aware of the issues and thinking that buying a cheaper Mode C
transponder today is a better decision than a slightly more expensive
Mode S transponder, especially when all the other important specs are
better with the Mode S. And I'd definitively not like to see us as a
community back in a situation where pilots are discussing debilitating
transponder power usage and more rounds of misinformation on power
consumption, and lack of use of transponders, because of this.

So Richard or Tim or anybody else do you have actual 12 VDC power
consumption specs on the Sandia transponder?

Darryl

[Tim Mara]

The only data available on the Sandia transponder is from their brouchure
(also on my website page in PDF)
but essentially says:
The STX 165 Sports a professional 1/2 3ATI Bezel that compliments any
aircraft panel. Its bright OLED
display is readable in virtually all lighting conditions and automatically
dims for night time operations. Check out just a few of the STX 165
features.

Built-in Encoder Simplifies installations and lowers cost.
Three Timer Functions Elapsed Flight Time, Up Timer, Down Timer
Pressure Altitude Display See what altitude your transponder is reporting
to Center
Optional OAT Probe Input Displays Outside Air Temp.,Density Altitude,
Icing Alert
Small and Light Weight 7.4" behind the panel depth, 1.3 lbs.
Low Current Requirements Ideal for LSA - Glider - UAV Operations

I have had these on order for several months so will get the very first ones
once they are releases..looks very promissing though for glider use noting
that they do say Low Current Requirements Ideal for LSA - Glider - UAV
Operations
please stand by!

I think also the next this to keep in mind and likely coming available
sometime in the not too distant future is UTA systems that I think you'll
find capabilities for this from Sandia to compliment their transponder
developement... http://www.itt.com/adsb/adsb-explained.html

Merry Chritmas!
Tim

Wings and Wheels -
http://www.wingsandwheels.com/Transponders%20encoders%20PCAS%20MRX%20XRX%20TTPAS %20Becker%20TRIG%20Microair.htm


And Tim there is advertising this new Sandia transponder as well. Jeez
Tim! Maybe Tim or Richard can clarify the actual 12 VDC power
consumption of the Sandia transponder.

I understand the USA Trig distributor wanted higher upfront commitment
from the channel than other distributors and that may be a reason why
fewer dealers are carrying them than other brands. I don't know why
Craggy Aero does not sell the Trig transponders. It would seems a very
natural fit for the PowerFLARM that Craggy Aero has been doing a great
job promoting.

As for the relative cost. Most glider pilots do just fine installing a
lower cost and lower power consumption 125W transponder (whether a new
Trig TT21 or the Becker ATC-4401-175 many of us use). So for new
transponders for gliders in the USA any price comparison really should
be against the street price of a TT21. It really is irrelevant that
the Sandia is a 200W transponder, that does not justify a price
comparison to a Trig TT22 200W transponder. And as others have pointed
out we need to be a little careful comparing advertised and actual
street prices.

It is great to see pilots using a transponder (any transponder) where
we have high density airliner and fast jet traffic etc. and a Mode S
or Mode C transponder works well there today (but its the long term
ADS-B future where a Mode S shines). But I'd hate to see glider pilots
not aware of the issues and thinking that buying a cheaper Mode C
transponder today is a better decision than a slightly more expensive
Mode S transponder, especially when all the other important specs are
better with the Mode S. And I'd definitively not like to see us as a
community back in a situation where pilots are discussing debilitating
transponder power usage and more rounds of misinformation on power
consumption, and lack of use of transponders, because of this.

So Richard or Tim or anybody else do you have actual 12 VDC power
consumption specs on the Sandia transponder?

Darryl

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[Darryl Ramm]

On Dec 9, 12:30*pm, "Tim Mara" > wrote:
> The only data available on the Sandia transponder is from their brouchure
> (also on my website page in PDF)
> but essentially says:
> The STX 165 Sports a professional 1/2 3ATI Bezel that compliments any
> aircraft panel. *Its bright OLED
> display is readable in virtually all lighting conditions and automatically
> dims for night time operations. *Check out just a few of the STX 165
> features.
>
> Built-in Encoder *Simplifies installations and lowers cost.
> Three Timer Functions *Elapsed Flight Time, Up Timer, Down Timer
> Pressure Altitude Display *See what altitude your transponder is reporting
> to Center
> Optional OAT Probe Input * Displays Outside Air Temp.,Density Altitude,
> Icing Alert
> Small and Light Weight *7.4" behind the panel depth, 1.3 lbs.
> Low Current Requirements *Ideal for LSA - Glider - UAV Operations
>
> I have had these on order for several months so will get the very first ones
> once they are releases..looks very promissing though for glider use noting
> that they do say *Low Current Requirements *Ideal for LSA - Glider - UAV
> Operations
> please stand by!
>
> I think also the next this to keep in mind and likely coming available
> sometime in the not too distant future is UTA systems that I think you'll
> find capabilities for this from Sandia to compliment their transponder
> developement...http://www.itt.com/adsb/adsb-explained.html
>
> Merry Chritmas!
> Tim

Tim, that is not all the data in the brochure. You left off the most
relevant actual numerical power consumption data, but included the
marketing fluff claims. The brochure states 500mA power consumption at
28VDC. Assuming perfect power supply behavior that translates to 1.1 A
current draw at 12VDC. That just seems an unusably high current draw
for use in gliders - can you check with Sandia on the correct 12 VDC
(or 14VDC) power consumption?

Sandia Aerospace has been active in UAT development and may well
beleive UATs are important for the USA market, but it is very
surprising they extrpolate this to justufy the development of a new
Mode C transponder. Sofar the lowest cost (non TSO) UAT transceivers
avalable would more than double the price again of this system to do
ADS-B data-out, and add even more power consumption (getting close to
2A?!) and that still gets you UAT only that will have significant
compatibility issues with the 1090ES link supported by PowerFLARM.

Besides all the other problems I'm just not sure I would want to buy a
product from a small company who thinks developing a Mode C
transponder in 2010 is a good idea. It gives me no confidence they
will be around to provide support in the future.

Darryl

[Tim Mara]

Actually the data on their brochure is actually pessimistic. In speaking
with the company directly this is all based on test data and in worst case
scenarios during warm up, transmitting on the 7777 frequency and at full
power...what they confirm as an estimate of current consumption at 12 VDC is
likely much closer to <500 mA .very doable in almost any glider application
and will operate down to <11 Volts.
There are several relevant arguments for both Mode C and also for UAT
including lower power requirements than Mode S (at similar power output) and
the possibility of simple and lower cost displays for all traffic, not
simply aircraft equipped with FLARM in that UAT will show all transponder
equipped aircraft. The cost appears higher but at an estimated price
possibility of about $3500 +/- that would not only include the UTA but the
transponder as well..We easily see prices in the same range for transponder
and FLARM / PowerFLARM equipment and the UAT can also provide a TCAS type
warning and display in a glider size package.
tim


"Darryl Ramm" > wrote in message
...
On Dec 9, 12:30 pm, "Tim Mara" > wrote:
> The only data available on the Sandia transponder is from their brouchure
> (also on my website page in PDF)
> but essentially says:
> The STX 165 Sports a professional 1/2 3ATI Bezel that compliments any
> aircraft panel. Its bright OLED
> display is readable in virtually all lighting conditions and automatically
> dims for night time operations. Check out just a few of the STX 165
> features.
>
> Built-in Encoder Simplifies installations and lowers cost.
> Three Timer Functions Elapsed Flight Time, Up Timer, Down Timer
> Pressure Altitude Display See what altitude your transponder is reporting
> to Center
> Optional OAT Probe Input Displays Outside Air Temp.,Density Altitude,
> Icing Alert
> Small and Light Weight 7.4" behind the panel depth, 1.3 lbs.
> Low Current Requirements Ideal for LSA - Glider - UAV Operations
>
> I have had these on order for several months so will get the very first
> ones
> once they are releases..looks very promissing though for glider use noting
> that they do say Low Current Requirements Ideal for LSA - Glider - UAV
> Operations
> please stand by!
>
> I think also the next this to keep in mind and likely coming available
> sometime in the not too distant future is UTA systems that I think you'll
> find capabilities for this from Sandia to compliment their transponder
> developement...http://www.itt.com/adsb/adsb-explained.html
>
> Merry Chritmas!
> Tim

Tim, that is not all the data in the brochure. You left off the most
relevant actual numerical power consumption data, but included the
marketing fluff claims. The brochure states 500mA power consumption at
28VDC. Assuming perfect power supply behavior that translates to 1.1 A
current draw at 12VDC. That just seems an unusably high current draw
for use in gliders - can you check with Sandia on the correct 12 VDC
(or 14VDC) power consumption?

Sandia Aerospace has been active in UAT development and may well
beleive UATs are important for the USA market, but it is very
surprising they extrpolate this to justufy the development of a new
Mode C transponder. Sofar the lowest cost (non TSO) UAT transceivers
avalable would more than double the price again of this system to do
ADS-B data-out, and add even more power consumption (getting close to
2A?!) and that still gets you UAT only that will have significant
compatibility issues with the 1090ES link supported by PowerFLARM.

Besides all the other problems I'm just not sure I would want to buy a
product from a small company who thinks developing a Mode C
transponder in 2010 is a good idea. It gives me no confidence they
will be around to provide support in the future.

Darryl



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database 5689 (20101209) __________

The message was checked by ESET NOD32 Antivirus.

http://www.eset.com





__________ Information from ESET NOD32 Antivirus, version of virus signature database 5689 (20101209) __________

The message was checked by ESET NOD32 Antivirus.

http://www.eset.com

[Darryl Ramm]

On Dec 9, 2:10*pm, "Tim Mara" > wrote:
> Actually the data on their brochure is actually pessimistic. In speaking
> with the company directly this is all based on test data and in worst case
> scenarios during warm up, transmitting on the 7777 frequency and at full
> power...what they confirm as an estimate of current consumption at 12 VDC is
> likely much closer to <500 mA .very doable in almost any glider application
> and will operate down to <11 Volts.
> There are several relevant arguments for both Mode C and also for UAT
> including lower power requirements than Mode S (at similar power output) and
> the possibility of simple and lower cost displays for all traffic, not
> simply aircraft equipped with FLARM in that UAT will show all transponder
> equipped aircraft. The cost appears higher but at an estimated price
> possibility of about $3500 +/- that would not only include the UTA but the
> transponder as well..We easily see prices in the same range for transponder
> and FLARM / PowerFLARM equipment and the UAT can also provide a TCAS type
> warning and display in a glider size package.
> tim

As has been covered in this thread. Yes a Mode S individual
interrogation rely may use more power than a Mode C reply (one that is
mostly no/null pulses) but a mode S transponder may well use less
power in practical situations that a Mode C due to the reduced number
of interrogations that the Mode S transponder will reply to. We see
that in practice, the Trig TT21 is flying in gliders with power
consumption < 300mA including encoder. Spectaculary low power
consumption - proving you can do this with a Mode S transponder.

A UAT based traffic system can provide a TCAS I like warning - every
traffic systems with direction information can provide a TCAS I like
traffic alert (TA). None, including Flarm or anything Sandia develop
based on a UAT can provide a TCAS II like RA. There is nothing unique
in that claim.

The "see all transponders" you mention is TIS-B. PowerFLARM does that
just just as well (and as bad) as a UAT receiver will well when the
PowewrFLARM equipped aircraft with 1090ES data-out. It has nothing to
do with using Mode C per-se.

To see that you need ADS-B data out either UAT or 1090ES and a
receiver (on the same link layer is preferred).

And you need to be within coverage of a GBT and the TIS-B service
needs to be deployed where you are flying (and the deployments differ
for en-route or terminal volumes). And even then the resolution of TIS-
B won't allow things like close flying of gliders etc.

The practical danger is that in many situations a PowerFLARM equipped
glider would see a glider equipped with Mode C becuase of the PCAS in
the PowerFLARM but this Sandia Mode C + UAT won't see a PowerFLARM
equipped glider at all because it won't be within GBT coverage, even
if the glider is transponder equipped.

So you really want to push Mode C + UAT as an alternative to
PowerFLARM? I hope people really get that the several hundred and
growing early orders for PowerFLARM in the USA means that thinking
about UAT technology and gliders in the USA is not a good idea. That
was last decade's dream that did not happen. It is a real concern that
we have critical traffic areas (like the white mountains and ridges
back east) where we need to think about technology to help avoid
glider on glider collisions and where mixed PowerFLARM and UAT
technology should not be expected to work. I hope potential purchasers
and dealers really understand the issues here. And where the primary
concern is glider on glider traffic all owners need to purchase is a
PowerFLARM (and they'll still get PCAS alerts for GA traffic as long
as that transponder equipped traffic is being interrogated).

Any though process for doing ADS-B via Mode C plus UAT ought to have
some *huge* benefit vs. PowerFLARM + 1090ES data-out. About the same
price and about the same power consumption (or more) but having
serious compatibility issues with a large number of PowerFLARM
equipped gliders seems a pretty dangerous direction to advocate.

Darryl

[Mike Schumann]

On 12/9/2010 6:16 PM, Darryl Ramm wrote:
> On Dec 9, 2:10 pm, "Tim > wrote:
>> Actually the data on their brochure is actually pessimistic. In speaking
>> with the company directly this is all based on test data and in worst case
>> scenarios during warm up, transmitting on the 7777 frequency and at full
>> power...what they confirm as an estimate of current consumption at 12 VDC is
>> likely much closer to<500 mA .very doable in almost any glider application
>> and will operate down to<11 Volts.
>> There are several relevant arguments for both Mode C and also for UAT
>> including lower power requirements than Mode S (at similar power output) and
>> the possibility of simple and lower cost displays for all traffic, not
>> simply aircraft equipped with FLARM in that UAT will show all transponder
>> equipped aircraft. The cost appears higher but at an estimated price
>> possibility of about $3500 +/- that would not only include the UTA but the
>> transponder as well..We easily see prices in the same range for transponder
>> and FLARM / PowerFLARM equipment and the UAT can also provide a TCAS type
>> warning and display in a glider size package.
>> tim
>
> As has been covered in this thread. Yes a Mode S individual
> interrogation rely may use more power than a Mode C reply (one that is
> mostly no/null pulses) but a mode S transponder may well use less
> power in practical situations that a Mode C due to the reduced number
> of interrogations that the Mode S transponder will reply to. We see
> that in practice, the Trig TT21 is flying in gliders with power
> consumption< 300mA including encoder. Spectaculary low power
> consumption - proving you can do this with a Mode S transponder.
>
> A UAT based traffic system can provide a TCAS I like warning - every
> traffic systems with direction information can provide a TCAS I like
> traffic alert (TA). None, including Flarm or anything Sandia develop
> based on a UAT can provide a TCAS II like RA. There is nothing unique
> in that claim.
>
> The "see all transponders" you mention is TIS-B. PowerFLARM does that
> just just as well (and as bad) as a UAT receiver will well when the
> PowewrFLARM equipped aircraft with 1090ES data-out. It has nothing to
> do with using Mode C per-se.
>
> To see that you need ADS-B data out either UAT or 1090ES and a
> receiver (on the same link layer is preferred).
>
> And you need to be within coverage of a GBT and the TIS-B service
> needs to be deployed where you are flying (and the deployments differ
> for en-route or terminal volumes). And even then the resolution of TIS-
> B won't allow things like close flying of gliders etc.
>
> The practical danger is that in many situations a PowerFLARM equipped
> glider would see a glider equipped with Mode C becuase of the PCAS in
> the PowerFLARM but this Sandia Mode C + UAT won't see a PowerFLARM
> equipped glider at all because it won't be within GBT coverage, even
> if the glider is transponder equipped.
>
> So you really want to push Mode C + UAT as an alternative to
> PowerFLARM? I hope people really get that the several hundred and
> growing early orders for PowerFLARM in the USA means that thinking
> about UAT technology and gliders in the USA is not a good idea. That
> was last decade's dream that did not happen. It is a real concern that
> we have critical traffic areas (like the white mountains and ridges
> back east) where we need to think about technology to help avoid
> glider on glider collisions and where mixed PowerFLARM and UAT
> technology should not be expected to work. I hope potential purchasers
> and dealers really understand the issues here. And where the primary
> concern is glider on glider traffic all owners need to purchase is a
> PowerFLARM (and they'll still get PCAS alerts for GA traffic as long
> as that transponder equipped traffic is being interrogated).
>
> Any though process for doing ADS-B via Mode C plus UAT ought to have
> some *huge* benefit vs. PowerFLARM + 1090ES data-out. About the same
> price and about the same power consumption (or more) but having
> serious compatibility issues with a large number of PowerFLARM
> equipped gliders seems a pretty dangerous direction to advocate.
>
> Darryl

I can't let this post go unanswered. Saying that PowerFlarm is the
answer for the glider community and UAT was last decade's dream is
pushing the limits. PowerFlarm doesn't even exist yet. UAT is the
FAA's recommended solution for GA, so I wouldn't be writing that off so
easily.

I'm not going to predict how this all falls out. There will undoubtedly
be lots of ADS-B solutions coming out in the next few years, both 1090ES
and UAT based. I'm not going to predict which way the market is going
to go, which will likely be heavily influenced by pricing.

If GARMIN decides to make a major push in this space for the single
engine VFR GA market, things could change in a very big way. Given the
size of this market, it's hard to imagine that GARMIN isn't going to
pursue this aggressively. If their mass market product is UAT based,
and you have 50-80% of the GA market equip, having gliders standardizing
on 1090ES is going to be a pretty bad move if you are flying low or in
remote areas, where you don't have ground station coverage to translate
between systems.

If you have the money and want to buy something right now, a 1090ES
capable Mode S transponder sounds like a reasonable investment.
PowerFlarm might also fall into that category IF you are an active
contest pilot, or are flying in an area where there are a critical mass
of glider pilots making the same investment in the near term.
Otherwise, at this point anything else is betting on untested marketing
spec sheets and speculating on a somewhat unpredictable market.

--
Mike Schumann

[Darryl Ramm]

On Dec 9, 7:07*pm, Mike Schumann >
wrote:
> On 12/9/2010 6:16 PM, Darryl Ramm wrote:
>
>
>
> > On Dec 9, 2:10 pm, "Tim > *wrote:
> >> Actually the data on their brochure is actually pessimistic. In speaking
> >> with the company directly this is all based on test data and in worst case
> >> scenarios during warm up, transmitting on the 7777 frequency and at full
> >> power...what they confirm as an estimate of current consumption at 12 VDC is
> >> likely much closer to<500 mA .very doable in almost any glider application
> >> and will operate down to<11 Volts.
> >> There are several relevant arguments for both Mode C and also for UAT
> >> including lower power requirements than Mode S (at similar power output) and
> >> the possibility of simple and lower cost displays for all traffic, not
> >> simply aircraft equipped with FLARM in that UAT will show all transponder
> >> equipped aircraft. The cost appears higher but at an estimated price
> >> possibility of about $3500 +/- that would not only include the UTA but the
> >> transponder as well..We easily see prices in the same range for transponder
> >> and FLARM / PowerFLARM equipment and the UAT can also provide a TCAS type
> >> warning and display in a glider size package.
> >> tim
>
> > As has been covered in this thread. Yes a Mode S individual
> > interrogation rely may use more power than a Mode C reply (one that is
> > mostly no/null pulses) but a mode S transponder may well use less
> > power in practical situations that a Mode C due to the reduced number
> > of interrogations that the Mode S transponder will reply to. We see
> > that in practice, the Trig TT21 is flying in gliders with power
> > consumption< *300mA including encoder. Spectaculary low power
> > consumption - proving you can do this with a Mode S transponder.
>
> > A UAT based traffic system can provide a TCAS I like warning - every
> > traffic systems with direction information can provide a TCAS I like
> > traffic alert (TA). None, including Flarm or anything Sandia develop
> > based on a UAT can provide a TCAS II like RA. There is nothing unique
> > in that claim.
>
> > The "see all transponders" you mention is TIS-B. PowerFLARM does that
> > just just as well (and as bad) as a UAT receiver will well when the
> > PowewrFLARM equipped aircraft with 1090ES data-out. It has nothing to
> > do with using Mode C per-se.
>
> > To see that you need ADS-B data out either UAT or 1090ES and a
> > receiver (on the same link layer is preferred).
>
> > And you need to be within coverage of a GBT and the TIS-B service
> > needs to be deployed where you are flying (and the deployments differ
> > for en-route or terminal volumes). And even then the resolution of TIS-
> > B won't allow things like close flying of gliders etc.
>
> > The practical danger is that in many situations a PowerFLARM equipped
> > glider would see a glider equipped with Mode C becuase of the PCAS in
> > the PowerFLARM but this Sandia Mode C + UAT won't see a PowerFLARM
> > equipped glider at all because it won't be within GBT coverage, even
> > if the glider is transponder equipped.
>
> > So you really want to push Mode C + UAT as an alternative to
> > PowerFLARM? I hope people really get that the several hundred and
> > growing early orders for PowerFLARM in the USA means that thinking
> > about UAT technology and gliders in the USA is not a good idea. That
> > was last decade's dream that did not happen. It is a real concern that
> > we have critical traffic areas (like the white mountains and ridges
> > back east) where we need to think about technology to help avoid
> > glider on glider collisions and where mixed PowerFLARM and UAT
> > technology should not be expected to work. I hope potential purchasers
> > and dealers really understand the issues here. And where the primary
> > concern is glider on glider traffic all owners need to purchase is a
> > PowerFLARM (and they'll still get PCAS alerts for GA traffic as long
> > as that transponder equipped traffic is being interrogated).
>
> > Any though process for doing ADS-B via Mode C plus UAT ought to have
> > some *huge* benefit vs. PowerFLARM + 1090ES data-out. About the same
> > price and about the same power consumption (or more) but having
> > serious compatibility issues with a large number of PowerFLARM
> > equipped gliders seems a pretty dangerous direction to advocate.
>
> > Darryl
>
> I can't let this post go unanswered. *Saying that PowerFlarm is the
> answer for the glider community and UAT was last decade's dream is
> pushing the limits. *PowerFlarm doesn't even exist yet. *UAT is the
> FAA's recommended solution for GA, so I wouldn't be writing that off so
> easily.
>
> I'm not going to predict how this all falls out. *There will undoubtedly
> be lots of ADS-B solutions coming out in the next few years, both 1090ES
> and UAT based. *I'm not going to predict which way the market is going
> to go, which will likely be heavily influenced by pricing.
>
> If GARMIN decides to make a major push in this space for the single
> engine VFR GA market, things could change in a very big way. *Given the
> size of this market, it's hard to imagine that GARMIN isn't going to
> pursue this aggressively. *If their mass market product is UAT based,
> and you have 50-80% of the GA market equip, having gliders standardizing
> on 1090ES is going to be a pretty bad move if you are flying low or in
> remote areas, where you don't have ground station coverage to translate
> between systems.
>
> If you have the money and want to buy something right now, a 1090ES
> capable Mode S transponder sounds like a reasonable investment.
> PowerFlarm might also fall into that category IF you are an active
> contest pilot, or are flying in an area where there are a critical mass
> of glider pilots making the same investment in the near term.
> Otherwise, at this point anything else is betting on untested marketing
> spec sheets and speculating on a somewhat unpredictable market.
>
> --
> Mike Schumann

PowerFLARM is coming - months away and hundreds of orders. The facts
are there are hundreds of glider pilots in the USA committing to buy
PowerFLARM and the number is growing. That is a huge factor in the
future ADS-B landscape for gliders in the USA that cannot be ignored.
Meanwhile there is still no UAT product suitable for use in gliders,
or any on the visible horizon. It exactly was last decades dream (for
the magical thing that was goign to solve all our glider collision
avoidance needs--that dream is dead). What UATs do in the GA market is
to be seen. As I have said multiple times, they may find a place
amongst GA aircraft with existing Mode C transponders, but overall I
am skeptical for market and packaging reasons they will ever become
more significant than 1090ES data-out in the GA market.

It is hard to be sure of Garmin's strategy here, but here is some
speculation since you raised it.... They have the GDL-90 UAT that was
relatively old technology from Apollo for the Capstone trials in
Alaska and they kept it around but it is pretty long in the tooth and
and they've not announced any updates/future plans yet AFAIK. Their
more recent focus was on adding 1090ES data-out options and upgrades
to their GTX330 and GTX33 transponders and adding 1090ES data-in as
standard on their GTS series traffic systems. L3 and Avidyne the two
other leading GA focused vendors of traffic awareness/alert systems
all have or are adding 1090ES data-in to their traffic systems. Not to
be unexpected for any active traffic system based on transponders--but
that is what the market leaders are doing.

I expect Garmin, L3, and Avidyne to take that 1090ES data-in
capability they have just added to their active TAS/TCAD systems and
and do much lower cost 1090ES data-in only systems around the same
hardware/software. If I was them I'd also do a UAT receive only
capability in that box to get FIS-B and dual-link traffic reception
(for when outside ADS-R coverage) and I would market it as pretty much
addressing most of the dual link ADS-B crap issues. All these vendors
have such good coverage with 1090ES already I'm not sure it justifies
a full parallel UAT product range but Garmin may well do a full
refresh on the GDL-90 who knows. What Garmin does, because they
dominate much of the transponder, display and WAAS GPS market will
have huge impact.

Zaon has been variously rumored to be doing different things,
including a multi-link 1090ES/PCAS/UAT receiver. Who knows what they
are really up to. But I kind of expect them not to do a certified
transmitter, a bit too much for them to bite off at a guess.

Trig has their own 1090ES receiver products coming into the market
that look a great match for 1090ES data-out in their transponders for
the GA market.

Recently Dynon the leading vendor of glass panel hardware for the
experimental market has OEMed the Trig TT series Mode S transponders
as back-ends to their Skyview systems. One could speculate on what
else they might OEM in 1090ES data-in land in future.

I expect Becker to do 1090ES data-in devices in future.

And we have NavWorx, FreeFlight and Sandia Aerospace doing UAT
receiver and transceiver products and SkyRadar doing their interesting
WiFi enabled UAT receiver.

But all of this is pretty academic, for several years, until we get
side service rollout and issues like the STC requirements for
installation of ADS-B data-out are removed. Until then most gliders
owners wanting collision avoidance technology can choose any
combination of Mode C or S transponders, PCAS devices (Zaon MRX) or
(soon) PowerFLARM depending on their need.

But one thing is clear, there is significant orders already in place
for PowerFLARM and that moves the glider community in the USA towards
a 1090ES ADS-B future.

Darryl

[Barry LeBlanc]

Hi,
I do not know if the thread is still open but wanted to jump in and make a statement or three. My name is Barry LeBlanc, Sandia Aerospace Representive. Here is a AC20-165A link. I have cut and posted some of the high lights.
FAA Advisory Circular AC No: 20-165A found on line at:
http://www.faa.gov/documentLibrary/media/Advisory_Circular/AC%2020-165A.pdf

3-2. ADS-B Equipment.
a. Equipment eligibility. ADS-B equipment must meet the requirements specified in TSO-C166b or TSO-C154c.
b. Installation guidance.
(1) UAT systems with Mode S transponders. Do not install a UAT ADS-B OUT system which has the capability to transmit a random 24-bit address in an aircraft which also has a Mode S transponder unless the random 24-bit feature is disabled. The ATC automation system would interpret the different 24-bit addresses as two separate aircraft, and alert controllers to a conflict that does not actually exist.
(2) Mixed transmit/receive classifications. TSO-C166b and TSO-C154c allow Class A transmit-only and Class A receive-only equipment configurations. There are no restrictions for installing a certain class of receive equipment with a different class of transmit equipment. For example, a Class A3 transmit-only unit can be used in the same aircraft with a Class A1 receive-only unit. It is also acceptable to have a TSO-C166b transmitter and a TSO-C154c receiver and vice versa.
(3) Stand alone 1090ES transmitters. RTCA/DO-260B, paragraph 2.2.2.2 only allows Class A0 and B0 1090ES stand-alone (not integrated with a transponder) transmitters. This AC does not cover installation approval for class A0 or B0 1090ES transmitters because they are not compliant with 14 CFR 91.227.

(4) Multiple ADS-B OUT systems. If the aircraft has the ability to operate a 1090ES and a UAT ADS-B OUT system at the same time, the systems must have a single point of entry for the emergency code, IDENT, and Mode 3/A code. Neither system may use a random address feature. If dual ADS-B OUT systems of the same link are installed (e.g., to increase dispatch reliability), the installation must preclude operation of both systems simultaneously

Note: 1: We recommend that you do not install both 1090ES and UAT ADS-B OUT capability on the same aircraft.


I have more to add. But my email is barry.leblanc at sandia.aero
Look forward to hearing from you why not a MODE C Transponder?