Hi All

I am contemplating getting a transponder for our LS3a. It seems the choice
is between either a 175W or 250W Becker "ATC 4401" unit or the Microair
"T2000".

Has anybody had first hand experience with any of the above?

What were your experiences, which unit would you recommend?

Which altitude encoder did you use?

What batteries do you use and how long do they last in flight?

Where did you mount the antenae?

Have you had any operational or reliability problems while flying?

The alternative might be to get hold of an old Terra unit. However these
seem virtually unobtainable, not very reliable and very
difficult/expensive to repair if/when they fail.


Thanks

Ian

Filser is currently developing a mode S unit. Depending on how their
schedule matches yours, you might have a look at it.

Stefan

"Ivan Kahn" > wrote...
> Before you invest in a transponder, call the facility with radar coverage in
> your area and find out if they routinely "supress" VFR codes during the
> times you fly. When the screen gets busy some facilities supress VFR codes,
> and so a transponder would in fact be a waste of money.

A transponder will trigger ACAS/TCAS, whether or not the controllers happen to
be paying attention to it...

Marc

I doubt that they would suppress 1200 within the approach control area
around a class B airspace (ModeC Veil)

BT

"Ivan Kahn" > wrote in message
news:lgw6b.378053$o%2.170703@sccrnsc02...
> Before you invest in a transponder, call the facility with radar coverage
in
> your area and find out if they routinely "supress" VFR codes during the
> times you fly. When the screen gets busy some facilities supress VFR
codes,
> and so a transponder would in fact be a waste of money.
>
> Ivan
>
>

"Ian Forbes" > wrote in message
. za...
> Hi All
>
> I am contemplating getting a transponder for our LS3a. It seems the choice
> is between either a 175W or 250W Becker "ATC 4401" unit or the Microair
> "T2000".


I have the 175 watt Becker with ACK A30 encoder in my 26E. No clue how long
the ship's 18 AH avionics battery would power it as there's solar panels on
the engine bay doors helping out. If I turned off WinPilot I could probably
sell power to the utility. In any case, I suspect it'll last way longer than
me. AFAIK the 250 watt Becker is only recommended if you spend a lot of time
in the upper flight levels.

Antenna is mounted on the belly just aft of the gear door. The thinking is
to get the antenna as far as possible, within reason, away from the pilot's
body. No sense testing the long term effects of high frequency radiation.

For the reasons you mentioned, the Terra isn't worth considering unless dirt
cheap. Even then, may not work long enough to justify cutting a rectangular
hole in the panel to mount it - - considering that you'll have a tough time
putting any other piece of gear in the non-standard hole.
--
bumper >
"Dare to be different . . . circle in sink."
to reply, the last half is right to left






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I think marc's statement concerning ACAS/TCAS is one of the best
reasons to fly with a transponder, along with facilitating the
extended use of some wave windows. I fly along/in mountainous areas
that have alot of bizjet/heavy aircraft decending over them and
although I haven't had any close calls, I've seen traffic come out of
nearby clouds (not on airways) going fast enough that I'm happy I had
something to let them know where I am before there is any visual
contact! I used to have a Terra, but it wouldn't fit in the
panel(it was hung off the side-in the way of egress) and parts aren't
available. I got a microaire and it's been easy to use, has worked
great, and didn't cost two arms and a leg.
Will

Class B airspace is used where there is heavy traffic, which is when VFR
codes are typically suppressed. My advice is only to make a phone call
before laying down your cash.

On the other hand, Marc does make a good point which is "A transponder will
trigger ACAS/TCAS, whether or not the controllers happen to be paying
attention to it..."

Ivan


"BTIZ" > wrote in message
news:kwy6b.46455$Qy4.20716@fed1read05...
> I doubt that they would suppress 1200 within the approach control area
> around a class B airspace (ModeC Veil)
>
> BT
>
> "Ivan Kahn" > wrote in message
> news:lgw6b.378053$o%2.170703@sccrnsc02...
> > Before you invest in a transponder, call the facility with radar
coverage
> in
> > your area and find out if they routinely "supress" VFR codes during the
> > times you fly. When the screen gets busy some facilities supress VFR
> codes,
> > and so a transponder would in fact be a waste of money.
> >
> > Ivan
> >
> >
>
>

I am not so sure if a transponder makes sense, if not in a powered
sailplane. I was told, that only with a transponder I could cross a
20km whide controlled airspace - ok - get a transponder in and
test fly it.

Same situation asking permission to cross the same area.
ATC: do you have a transponder ... yes
the usual switch on procedure followed and then the permit to
cross the airspace ending with - keep flight level at xxxxxx ft
my answer: glider CH cannot keep flight level
ATC: withdraws permit to cross airspace
(too much work to shuffle traffic vertically as well!!!!!!!!!!!!!!!)
ok then - rip the transponder out.

- Transponders for gliders are just battery flattening
- we should have a receiver telling us, where the big birds are
comming from

Chris


"Ian Forbes" > wrote in message
. za...
> Hi All
>
> I am contemplating getting a transponder for our LS3a. It seems the choice
> is between either a 175W or 250W Becker "ATC 4401" unit or the Microair
> "T2000".
>
> Has anybody had first hand experience with any of the above?
>
> What were your experiences, which unit would you recommend?
>
> Which altitude encoder did you use?
>
> What batteries do you use and how long do they last in flight?
>
> Where did you mount the antenae?
>
> Have you had any operational or reliability problems while flying?
>
> The alternative might be to get hold of an old Terra unit. However these
> seem virtually unobtainable, not very reliable and very
> difficult/expensive to repair if/when they fail.
>
>
> Thanks
>
> Ian

In article <e1G6b.380978$Ho3.57571@sccrnsc03>,
says...
> Class B airspace is used where there is heavy traffic, which is when VFR
> codes are typically suppressed. My advice is only to make a phone call
> before laying down your cash.

I don't think I understand this. Do you mean...

1) VFR codes are suppressed WITHIN class B airspace? Normally, there
wouldn't be any VFR codes in class B airspace, as aircraft with these
codes would not be allowed to enter.

2) VFR codes are suppressed beyond the perimeter of the Class B
airspace?

3) VFR codes are excluded in the "30 nautical mile Mode C veil" (some
Class B areas), where transponders with Mode C are required (with some
exceptions, like for gliders)?

My understanding is the areas around Class B airspace typically have
heavy VFR traffic, and that the controllers want to see all the VFR
traffic so they can keep their IFR traffic clear of the VFR traffic.
Suppressing VFR returns when there is heavy traffic seems very
counterproductive to this goal! Wasn't the Class B Mode C veil
implemented to make the VFR transponder returns more useful to ATC?
--
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directly

Eric Greenwell
Richland, WA (USA)

In article >,
says...
> I am not so sure if a transponder makes sense, if not in a powered
> sailplane. I was told, that only with a transponder I could cross a
> 20km whide controlled airspace - ok - get a transponder in and
> test fly it.
>
> Same situation asking permission to cross the same area.
> ATC: do you have a transponder ... yes
> the usual switch on procedure followed and then the permit to
> cross the airspace ending with - keep flight level at xxxxxx ft
> my answer: glider CH cannot keep flight level
> ATC: withdraws permit to cross airspace
> (too much work to shuffle traffic vertically as well!!!!!!!!!!!!!!!)
> ok then - rip the transponder out.

Where did this take place?

>
> - Transponders for gliders are just battery flattening
> - we should have a receiver telling us, where the big birds are
> comming from

Actually, they have a receiver telling them where we are coming from,
IF we have transponder (at least in the USA - not sure where you are).


--
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directly

Eric Greenwell
Richland, WA (USA)

happened in central Europe
but now I am flying in Australia
where a bit more airspace is left for us
:-)
Chris

"Eric Greenwell"
> wrote in message >

> Where did this take place?
> Eric Greenwell
> Richland, WA (USA)

> Subject: Re: Which Transponder?
> From: "Ivan Kahn" >
> Date: Wed, 10 Sep 2003 20:45:04 GMT

> Suppression of VFR codes is an option selectable at each
> radar controllers station. If he or she selects to surpress
> VFR codes then all VFR codes on his or her display will
> disappear. This only effects that one controller's display.

> controller to see VFR traffic. But when things get really
> busy the controller has the option to surpress. Keep in mind
> that when they are busy they will only work IFR traffic and VFR
> aircraft (on discrete codes) going to/from the primary airport.
> So the only traffic outside of Class B, for which non-participating
> VFR traffic is of concern, will be IFR operations to secondary
> airports. In those cases they can turn-off suppression while working
> one of then and then turn it back on once the handoff is completed.

So, are you saying that while an IFR aircraft is outside of Class B
airspace, and under ATC control, then ATC will turn off suppression so
they can see the VFR traffic?

If I've got that right, then isn't that what we want? ATC will keep
IFR aircraft away from VFR aircraft (that's me in my glider with my
transponder) while I'm outside of Class B airspace (the usual
situation).

I've never expected ATC to keep VFR aircraft away from me, though this
can happen if the VFR traffic is using Flight Following.

----------------------------
!Replace DECIMAL.POINT in my e-mail address with just a . to reply
directly

Eric Greenwell
Richland, WA (USA)

IF they are suppressing due to excess clutter, and IF they then turn
suppression off they will see VFR traffic. Normally, they do not suppress.

This began as a suggestion only to call ATC to find out if, and when, they
suppress in your are before spending the money. There are other things, such
as TCAS, which may well be reason enough to purchase a transponder.

Ivan

> So, are you saying that while an IFR aircraft is outside of Class B
> airspace, and under ATC control, then ATC will turn off suppression so
> they can see the VFR traffic?
>
> If I've got that right, then isn't that what we want? ATC will keep
> IFR aircraft away from VFR aircraft (that's me in my glider with my
> transponder) while I'm outside of Class B airspace (the usual
> situation).
>
> I've never expected ATC to keep VFR aircraft away from me, though this
> can happen if the VFR traffic is using Flight Following.
>
> ----------------------------
> !Replace DECIMAL.POINT in my e-mail address with just a . to reply
> directly
>
> Eric Greenwell
> Richland, WA (USA)

In article <Ls58b.317778$cF.96452@rwcrnsc53>,
says...
> IF they are suppressing due to excess clutter, and IF they then turn
> suppression off they will see VFR traffic. Normally, they do not suppress.
>
> This began as a suggestion only to call ATC to find out if, and when, they
> suppress in your are before spending the money. There are other things, such
> as TCAS, which may well be reason enough to purchase a transponder.

I pursued it because I was startled by the suggestion that people
responsible for separating traffic would remove some of that traffic
from their screens when it was most needed. As a counter example, at
our annual wave window meeting with the Seattle Center folks, they
specifically stated they never suppress transponder returns, but do
sometimes suppress "clutter", which might include non-transponder
equipped gliders circling or nearly stationary in a wave.

Regardless, a phone call is cheap, and I hope if anyone is told by ATC
that they do suppress VFR transponders, they'll let us know where that
is!
--
!Replace DECIMAL.POINT in my e-mail address with just a . to reply
directly

Eric Greenwell
Richland, WA (USA)

On Thu, 11 Sep 2003 21:05:48 +0000, Ivan Kahn wrote:

> This began as a suggestion only to call ATC to find out if, and when, they
> suppress in your are before spending the money. There are other things,
> such as TCAS, which may well be reason enough to purchase a transponder.

Actually I started this thread to find out what others are using before
paying out a small fortune for a transponder.

I fly from Worcester near Cape Town in South Africa. Without a transponder
we are limited to below FL085. With a transponder we can get cleared
to FL120 on most days and FL200 or higher with a co-operative controller.

If I do buy one, the idea is to get a diamond height without taking a long
and very expensive holiday! Wave flying from Worcester is really awsome it
would be a pity to go somewhere else to fly the diamond. Have a look at
our club's homepage for a sample pic, http://www.cgc.org.za/


Ian

In article >,
says...
> On Thu, 11 Sep 2003 21:05:48 +0000, Ivan Kahn wrote:
>
> > This began as a suggestion only to call ATC to find out if, and when, they
> > suppress in your are before spending the money. There are other things,
> > such as TCAS, which may well be reason enough to purchase a transponder.
>
> Actually I started this thread to find out what others are using before
> paying out a small fortune for a transponder.
>
> I fly from Worcester near Cape Town in South Africa. Without a transponder
> we are limited to below FL085. With a transponder we can get cleared
> to FL120 on most days and FL200 or higher with a co-operative controller.
>
> If I do buy one, the idea is to get a diamond height without taking a long
> and very expensive holiday! Wave flying from Worcester is really awsome it
> would be a pity to go somewhere else to fly the diamond. Have a look at
> our club's homepage for a sample pic, http://www.cgc.org.za/

FL085? Gulp! It sounds like a transponder would be worth the effort
and expense. I'm using the Becker ATC 4401 (175 watt version). At the
time I bought mine, neither it nor the Microair had been out long, so
I decided the Becker was a lesser risk and not much more costly.
--
!Replace DECIMAL.POINT in my e-mail address with just a . to reply
directly

Eric Greenwell
Richland, WA (USA)

TCAS in my opinion is why you need a transponder! They cost less than a GPS
used to cost and they my keep a 737 or such from running over you. I fly at
the south end of the Dallas Ft Worth TCA and when the wind is from the
north they run Southwest 737's and anything going to Love Field into our
soaring area at and below cloud base. You can buy a Becker transponder or
the other one and have it installed for less than $2,000. This price doesn't
seem to be excessive to me for the mid-air protection that it might provide
you, squawking "1200" and looking around.
Bob Kibby "2BK"




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"Ivan Kahn" > wrote in message
news:Ls58b.317778$cF.96452@rwcrnsc53...
> IF they are suppressing due to excess clutter, and IF they then turn
> suppression off they will see VFR traffic. Normally, they do not suppress.
>
> This began as a suggestion only to call ATC to find out if, and when, they
> suppress in your are before spending the money. There are other things,
such
> as TCAS, which may well be reason enough to purchase a transponder.
>
> Ivan
>
> > So, are you saying that while an IFR aircraft is outside of Class B
> > airspace, and under ATC control, then ATC will turn off suppression so
> > they can see the VFR traffic?
> >
> > If I've got that right, then isn't that what we want? ATC will keep
> > IFR aircraft away from VFR aircraft (that's me in my glider with my
> > transponder) while I'm outside of Class B airspace (the usual
> > situation).
> >
> > I've never expected ATC to keep VFR aircraft away from me, though this
> > can happen if the VFR traffic is using Flight Following.
> >
> > ----------------------------
> > !Replace DECIMAL.POINT in my e-mail address with just a . to reply
> > directly
> >
> > Eric Greenwell
> > Richland, WA (USA)
>
>