Transponderz

On Saturday, November 3, 2012 2:29:03 PM UTC-7, Mike C wrote:
On Nov 3, 8:59*am, Dave Nadler wrote:

On Friday, November 2, 2012 8:45:43 PM UTC-4, Mike C wrote:

I am wondering if using Oshkosh as an example applicable to a few

sailplanes, in a thermal, is not a bit of a strawman argument.



Oshkosh was used as an example of where Mode A/C cannot work.



A separate point, it is my impression that *traffic is so congested

there that the controllers are overwhelmed, not that the signals are

garbled and unreadable.



"Your impression" ? The controllers are not overwhelmed, they use

appropriate tools and manage the highest traffic density anywhere,

very professionally. As you would know if you've flown into

Oshkosh (or in the airshow ;-)



Mode C is valid, safe and not the worthless tired technology

that it seems to be portrayed as.



Sure, which is why Mode C was phased out in Germany years ago,

with the rest of the world following...



For new installations, get Mode S and we'll all be happier

with the results. And it won't have to be replaced if/when

FAA catches up with the rest of the world (not holding my

breath).



Mode C does work in many cases, but...



Dave,



Are you sure that the reason that formation pilots only have one

transponder on, is not because of collision alerts with aircraft in

close proximity of each other? That is what I was told. Also told the

reason transponders are turned off is because of alerts in heavy

traffic



Mike.

No, the reason for all but the formation leader in going squawk standby in formations is 'garbling' with all the Mode A/C transponders otherwise replying to the same interrogation and the SSR *possibly* being unable to decode the signal from each aircraft. Modern SSR systems also have pretty advanced decorrelators that can untangle several overlapping replies. This is something that dates back to the earliest days of SSR radar and is discussed in the FAA AIM, ATC Procedures section.

PCAS type systems may also be affected by garbling, but this is not the reason ATC cares about it. You can sometimes see what I expect are the garbling effects with Mode A/C transponders with when you formation fly with an aircraft and it dissapears intermittently.

But to Eric's points, just don't worry about all this wonky geek crap. If any of this was really worth worrying about you'd have the ATC folks who work closely with the glider community in busy traffic places raising it as an issue. And AFAIK they have never done that--all the discussions I have with those folks, both civil and military is they just want to see transponder adoption near their airspace, Mode C, Mode S they don't care.

And fly the glider. I'd hate to be in gaggles where folks are coordinating who's turning off transponders, then you have to remember to turn them back on again.

OTOH if you are flying in large gaggles near a busy ATC facility you have lots of very real reasons to be talking to your friendly ATC folks, not there are far more important things to talk about than the possibility of garbling. And I certainly expect those ATC folks to notice the presence of large gaggles even with severe garbling.


Darryl

Sorry - I was unaware of that.

Guess I'll have to just suffer the bad spelin' and gramr...


"Darryl Ramm" wrote in message
...
"Dan Marotta" wrote:
Just had to change the atrocious spelling in the subject line...

And that mostly just annoys a lot of people, forks the thread in many
newsreaders etc. Leave usenet subject lines alone please.

Darryl

Back in my military flying days, only the flight leader squawked; wingmen
set their transponders to STBY. When/if the formation broke up, everyone
squawked an assigned code.


"Mike C" wrote in message
...
On Nov 3, 8:59 am, Dave Nadler wrote:
On Friday, November 2, 2012 8:45:43 PM UTC-4, Mike C wrote:
I am wondering if using Oshkosh as an example applicable to a few
sailplanes, in a thermal, is not a bit of a strawman argument.

Oshkosh was used as an example of where Mode A/C cannot work.

A separate point, it is my impression that traffic is so congested
there that the controllers are overwhelmed, not that the signals are
garbled and unreadable.

"Your impression" ? The controllers are not overwhelmed, they use
appropriate tools and manage the highest traffic density anywhere,
very professionally. As you would know if you've flown into
Oshkosh (or in the airshow ;-)

Mode C is valid, safe and not the worthless tired technology
that it seems to be portrayed as.

Sure, which is why Mode C was phased out in Germany years ago,
with the rest of the world following...

For new installations, get Mode S and we'll all be happier
with the results. And it won't have to be replaced if/when
FAA catches up with the rest of the world (not holding my
breath).

Mode C does work in many cases, but...

Dave,

Are you sure that the reason that formation pilots only have one
transponder on, is not because of collision alerts with aircraft in
close proximity of each other? That is what I was told. Also told the
reason transponders are turned off is because of alerts in heavy
traffic

Mike.

On Saturday, November 3, 2012 6:33:26 PM UTC-6, Dan Marotta wrote:
Sorry - I was unaware of that.

Guess I'll have to just suffer the bad spelin' and gramr...

Just had to change the atrocious spelling in the subject line...


Dan,
God, I am so sorry for making you suffer. Can I buy you dinner at the next convention? I swear that if I start another TX thread I will not use a plural tense and end it in a Z. You have my word.
The reason I started this thread is because there seems to be an ever increasing variety of these things (Including something called a Sandia STX165 on WW) and I was wondering if I would end up with something that would be obsolete with the implementation of ADS-B. I have intended Mode S from the start.
I flew most of last season with the portable PF and it worked great with transponders and the occasional ADS-B but I did not get much chance to fly with other PFs.
Will probably go with the Trig. Thanks to everyone for the comments.

On Saturday, November 3, 2012 6:18:45 PM UTC-7, K wrote:
On Saturday, November 3, 2012 6:33:26 PM UTC-6, Dan Marotta wrote:

Sorry - I was unaware of that.



Guess I'll have to just suffer the bad spelin' and gramr...



Just had to change the atrocious spelling in the subject line...





Dan,

God, I am so sorry for making you suffer. Can I buy you dinner at the next convention? I swear that if I start another TX thread I will not use a plural tense and end it in a Z. You have my word.

The reason I started this thread is because there seems to be an ever increasing variety of these things (Including something called a Sandia STX165 on WW) and I was wondering if I would end up with something that would be obsolete with the implementation of ADS-B. I have intended Mode S from the start.

I flew most of last season with the portable PF and it worked great with transponders and the occasional ADS-B but I did not get much chance to fly with other PFs.

Will probably go with the Trig. Thanks to everyone for the comments.

So there is one possible thing to consider with Mode-S transponders and possible ADS-B data-out futures. If I was buying any Mode-S transponder today lookign for that future ADS-B data-out possibility I would buy a higher power output transponder (in the case of the Trig that's the TT-22).

This is different than the operation as a transponder and any of the class 1 / class 2 approval and suitable use questions that have come up on r.a.s in the past. Its just that AFAIK the FAA is still not clear on final ADS-B data-out power requirements. The Trig TT-21 and similar lower power transponders all meet RTCA DO-260B and other standards for 1090ES data-out but its unclear (at least to me) if that will be acceptable to the FAA or if they will actually end up requiring a higher output power to enable communications via the FAA's ADS-B GBTs (Ground Based Transceivers). While I would have hoped the FAA spaced the GBTs close enough that current spec low-power 1090ES data-out would be compatible its not clear that is what finally happened. And who knows what would happen in practice, possibly the devices could still be installed, but if an install needs an STC (as currently) or TSO approved device or is otherwise strictly enforced you may have no ADS-B data-out option.

Sorry for the lack of hard info, I don't want to worry anybody and I wish I was more up to speed on the status here. This is just a personal caution, and again remember that if you are buying a transponder for ADS-B data-out futures that is all currently a world of hurt, at least for certified aircraft, with STC requirements and IFR/TSO'ed GPS requirements. And there are uncertainties with what will happen with 'non-complaint' installs in experiential aircraft. Personally I'd get a Trig TT-21 or TT-22 today for lots of reasons, but probably go for the TT-22 just to cover my ass a bit on the output power uncertainty.

I'd not hold my breath for the FAA to sort out ADS-B data-out mess. Both the Trig TT-21 and TT-22 are just fantastic transponders. Another way to look at either of these is in a decade you just throw them out, that two hundred dollars or so per year. Money likely very well spent if fly near airliners, fast jets and busy GA traffic.

As stated before but several of us here, buying a Mode C transponder today makes _no_ sense, and the Sandia STX165 is a Mode C transponder. It seems a case of a vendor following silly FAA thinking that the future for GA is Mode C + UAT data out/in. Unfortunately organizations like AOPA also wanted/supported this, at least in concept, instead of calling bull**** on the whole FAA ADS-B dual-link mess.

Thanks for flying with a transponder.

Darryl

On Nov 3, 8:03*pm, Darryl Ramm wrote:
On Saturday, November 3, 2012 6:18:45 PM UTC-7, K wrote:
On Saturday, November 3, 2012 6:33:26 PM UTC-6, Dan Marotta wrote:

Sorry - I was unaware of that.

Guess I'll have to just suffer the bad spelin' and gramr...

Just had to change the atrocious spelling in the subject line...

Dan,

God, I am so sorry for making you suffer. Can I buy you dinner at the next convention? I swear that if I start another TX thread I will not use a plural tense and end it in a Z. You have my word.

The reason I started this thread is because there seems to be an ever increasing variety of these things (Including something called a Sandia STX165 on WW) and I was wondering if I would end up with something that would be obsolete with the implementation of ADS-B. I have intended Mode S from the start.

I flew most of last season with the portable PF and it worked great with transponders and the occasional ADS-B but I did not get much chance to fly with other PFs.

Will probably go with the Trig. Thanks to everyone for the comments.

So there is one possible thing to consider with Mode-S transponders and possible ADS-B data-out futures. If I was buying any Mode-S transponder today lookign for that future ADS-B data-out possibility I would buy a higher power output transponder (in the case of the Trig that's the TT-22).

This is different than the operation as a transponder and any of the class 1 / class 2 approval and suitable use questions that have come up on r.a.s in the past. Its just that AFAIK the FAA is still not clear on final ADS-B data-out power requirements. The Trig TT-21 and similar lower power transponders all meet RTCA DO-260B and other standards for 1090ES data-out but its unclear (at least to me) if that will be acceptable to the FAA or if they will actually end up requiring a higher output power to enable communications via the FAA's ADS-B GBTs (Ground Based Transceivers). While I would have hoped the FAA spaced the GBTs close enough that current spec low-power 1090ES data-out would be compatible its not clear that is what finally happened. And who knows what would happen in practice, possibly the devices could still be installed, but if an install needs an STC (as currently) or TSO approved device or is otherwise strictly enforced you may have no ADS-B data-out option.

Sorry for the lack of hard info, I don't want to worry anybody and I wish I was more up to speed on the status here. This is just a personal caution, and again remember that if you are buying a transponder for ADS-B data-out futures that is all currently a world of hurt, at least for certified aircraft, *with STC requirements and IFR/TSO'ed GPS requirements. And there are uncertainties with what will happen with 'non-complaint' installs in experiential aircraft. Personally I'd get a Trig TT-21 or TT-22 today for lots of reasons, but probably go for the TT-22 just to cover my ass a bit on the output power uncertainty.

I'd not hold my breath for the FAA to sort out ADS-B data-out mess. Both the Trig TT-21 and TT-22 are just fantastic transponders. Another way to look at either of these is in a decade you just throw them out, that two hundred dollars or so per year. Money likely very well spent if fly near airliners, fast jets and busy GA traffic.

As stated before but several of us here, buying a Mode C transponder today makes _no_ sense, and the Sandia STX165 is a Mode C transponder. It seems a case of a vendor following silly FAA thinking that the future for GA is Mode C + UAT data out/in. Unfortunately organizations like AOPA also wanted/supported this, at least in concept, instead of calling bull**** on the whole FAA ADS-B dual-link mess.

Thanks for flying with a transponder.

Darryl

Thanks for the info Darryl.

My choice at the time was a Mode S and no Flarm or a really great deal
on a Sandia Mode C and a Flarm.

Some of us have to make compromises based on income.

Mike

K,

Where/when's the convention? I haven't been to one yet. And please don't
take my rants personal; it's just that time of year...

I've got a Trig TT22 and am very happy with it. I don't see jets nearly as
closely as I used to. I had some installation problems, mainly with routing
the wiring from under the floor of my cockpit to the instrument panel and a
shorted wire in the DB-9 connector. The factory support was quick and
responsive and I made repairs. I bought a prewired cable but had to cut one
connector off to route the cable. The short circuit was my fault. Since
then, it has performed flawlessly.


"K" wrote in message
...
On Saturday, November 3, 2012 6:33:26 PM UTC-6, Dan Marotta wrote:
Sorry - I was unaware of that.

Guess I'll have to just suffer the bad spelin' and gramr...

Just had to change the atrocious spelling in the subject line...


Dan,
God, I am so sorry for making you suffer. Can I buy you dinner at the next
convention? I swear that if I start another TX thread I will not use a
plural tense and end it in a Z. You have my word.
The reason I started this thread is because there seems to be an ever
increasing variety of these things (Including something called a Sandia
STX165 on WW) and I was wondering if I would end up with something that
would be obsolete with the implementation of ADS-B. I have intended Mode S
from the start.
I flew most of last season with the portable PF and it worked great with
transponders and the occasional ADS-B but I did not get much chance to fly
with other PFs.
Will probably go with the Trig. Thanks to everyone for the comments.

On Sunday, November 4, 2012 8:24:39 AM UTC-7, Dan Marotta wrote:
K,



Where/when's the convention? I haven't been to one yet. And please don't

take my rants personal; it's just that time of year...

The SSA convention is every other year. Since the last one was in 2012 in Reno the next one will be January of 2014 at the other end of the country. IIRC the last time I spoke to the people in Hobbs they were looking at Florida. You should go to one of these. They are fun and educational and you will meet many of the people on this board and just about everyone who is anyone in the sport.
Nothing personal of course, I was just being silly.