Becker transponder max operating altitude

The operating manual for the Becker ATC 4401-1-xxx transponder has the
following specifications:
(http://www.beckerusa.com/products/de...4401-1-I+O.pdf)

Max. operating altitude :
- ATC 4401-1-175 15000 ft.
- ATC 4401-1-250 50000 ft.

and

Flight level code (mode C) ICAO coding system 100-foot steps from
- ATC 4401-1-175 -1000 to 31000 ft.
- ATC 4401-1-250 -1000 to 62700 ft.

Does anyone know what exactly this means? Is the 175W unit not really
usable in sailplanes that plan to fly in the USA in areas where one
would go above 15K?

-Tom

5Z wrote:
The operating manual for the Becker ATC 4401-1-xxx transponder has the
following specifications:
(http://www.beckerusa.com/products/de...4401-1-I+O.pdf)

Max. operating altitude :
- ATC 4401-1-175 15000 ft.
- ATC 4401-1-250 50000 ft.

and

Flight level code (mode C) ICAO coding system 100-foot steps from
- ATC 4401-1-175 -1000 to 31000 ft.
- ATC 4401-1-250 -1000 to 62700 ft.

Does anyone know what exactly this means? Is the 175W unit not really
usable in sailplanes that plan to fly in the USA in areas where one
would go above 15K?

-Tom
Tom,
The 175 replies with 175 watts & the 225 replies with 225 watts. I'm
thinking the 175 is made for little bug smashers like we fly & the 225
is something you'd put into your C-210 or Piper Malibu and such. The
175 I've got seems to make the big brown turd looking Southwest jets
kinda steer around my little glider even at 12-14k. I can make my 2
sets of batteries last about 6-7 hrs and still see 11.5 v in each set
(8ah each set). I see the reply light going even on the Whites. It
will even work up to 50,000' but it's only going to reply with 175 w.
The closer you are to the antenna the better they will paint you. The
more wattage you reply with the better and further they can paint you.
I'd think that TCAS would pick either one up easily at 5-10 miles. As
far as the steps go your encoder replies with pressure altitude in 100'
incriments reliably up to the certified alt's (and probably beond but
not certified).
Russ

Hi,

I'm not so sure that the 175 model can (or at least should) be used above
15,000 feet. If I owned one I probably wouldn't turn it off above 15,000
feet, but the data below seems to indicate that it will not work above
31,000 feet. My guess is that they created 2 versions so that glider
pilots that never (or rarely) fly above 15,000 feet would not need to extra
power drain of the 250 W version. Glider pilots that fly over 15,000 feet
often should (in my opinion) use the 250 W version - because it was designed
for, tested, and certified for use at those altitudes. If the 175 W version
would have worked OK at high altitudes, they wouldn't have needed the 250W
version. Remember that the amplitude of the signal drops off with the cube
of the distance. The range of the 175W model would be much less than the
250 W version.

The good news is that the 250W version is only $200 more than 175W version.

The brochure shows that the power consumption for the 250W version is a bit
more.

Typical Consumption at 5544 (1200/sec) - (I don't know what the "5544
(1200/sec)" means)
0.50 A at 13.75 V (250 W)
0.40 A at 13.75 V (175 W)

I have links to the brochures and manuals on my web site he:
http://www.cumulus-soaring.com/becker.htm

I am not an expert on transponders, but those are my observations.

Good Soaring,

Paul Remde
Cumulus Soaring, Inc.
http://www.cumulus-soaring.com

wrote in message
ups.com...
5Z wrote:
The operating manual for the Becker ATC 4401-1-xxx transponder has the
following specifications:
(http://www.beckerusa.com/products/de...4401-1-I+O.pdf)

Max. operating altitude :
- ATC 4401-1-175 15000 ft.
- ATC 4401-1-250 50000 ft.

and

Flight level code (mode C) ICAO coding system 100-foot steps from
- ATC 4401-1-175 -1000 to 31000 ft.
- ATC 4401-1-250 -1000 to 62700 ft.

Does anyone know what exactly this means? Is the 175W unit not really
usable in sailplanes that plan to fly in the USA in areas where one
would go above 15K?

-Tom
Tom,
The 175 replies with 175 watts & the 225 replies with 225 watts. I'm
thinking the 175 is made for little bug smashers like we fly & the 225
is something you'd put into your C-210 or Piper Malibu and such. The
175 I've got seems to make the big brown turd looking Southwest jets
kinda steer around my little glider even at 12-14k. I can make my 2
sets of batteries last about 6-7 hrs and still see 11.5 v in each set
(8ah each set). I see the reply light going even on the Whites. It
will even work up to 50,000' but it's only going to reply with 175 w.
The closer you are to the antenna the better they will paint you. The
more wattage you reply with the better and further they can paint you.
I'd think that TCAS would pick either one up easily at 5-10 miles. As
far as the steps go your encoder replies with pressure altitude in 100'
incriments reliably up to the certified alt's (and probably beond but
not certified).
Russ

Paul Remde wrote:
Hi,

I'm not so sure that the 175 model can (or at least should) be used above
15,000 feet. If I owned one I probably wouldn't turn it off above 15,000
feet, but the data below seems to indicate that it will not work above
31,000 feet. My guess is that they created 2 versions so that glider
pilots that never (or rarely) fly above 15,000 feet would not need to extra
power drain of the 250 W version.

I'm very curious about this, also, but I doubt the glider market is big
enough to affect a decision to make another version! I'm guessing it's
designed for VFR pilots that will be staying low because of aircraft
performance or are without an oxygen system, a much bigger market than
gliders.

Glider pilots that fly over 15,000 feet
often should (in my opinion) use the 250 W version - because it was designed
for, tested, and certified for use at those altitudes. If the 175 W version
would have worked OK at high altitudes, they wouldn't have needed the 250W
version.

The 175 W version will operate at 30,000' just fine. It's not a
technical issue, but, I suspect, an ATC issue: they want to see the high
speed IFR traffic in Class A airspace from a long distance away.

Remember that the amplitude of the signal drops off with the cube
of the distance.

Actually, with the (inverse) square of the distance. Think of the area
of expanding sphere as it's radius increases.

The range of the 175W model would be much less than the
250 W version.

The range difference would be about the square root of (175/250), or 84%
of the 250 watt unit. It's this range insensitivity to output power that
is the key to the PCAS units (like the Zaon MRX unit) ability to
indicate how far away the other aircraft is.


The good news is that the 250W version is only $200 more than 175W version.

The brochure shows that the power consumption for the 250W version is a bit
more.

Typical Consumption at 5544 (1200/sec) - (I don't know what the "5544
(1200/sec)" means)

The 1200/sec is the number of interrogations per second; the 5544 might
be the code set in the transponder, as the code affects the power
consumption.

0.50 A at 13.75 V (250 W)
0.40 A at 13.75 V (175 W)

--
Note: email address new as of 9/4/2006
Change "netto" to "net" to email me directly

Eric Greenwell - Washington State, USA

"Transponders in Sailplanes" on the Soaring Safety Foundation website
www.soaringsafety.org/prevention/articles.html

"A Guide to Self-launching Sailplane Operation" at www.motorglider.org

"The range of the 175W model would be much less than the 250 W version."

Not true. The difference in output is 2 db. The only time there will be a
substantial difference is when you are at the threshold of the 175 watt
signal. The difference between high power and low power would be more
significant at lower altitudes, when you are shadowed from the radar. At
high altitudes, you are more likely to have a clear shot to the radar.

I think there is a balance between power and battery life.

I do not know the significance of the difference in altitude specification
between the two units. The manual clearly states that the maximum altitude
for the 175 watt unit is 15,000 feet. It would be necessary to understand
the reason for this statement before it is prudent to ignore it. It may be
regulatory, rather than technical.

Colin

COLIN LAMB wrote:
"The range of the 175W model would be much less than the 250 W version."

Not true. The difference in output is 2 db. The only time there will be a
substantial difference is when you are at the threshold of the 175 watt
signal. The difference between high power and low power would be more
significant at lower altitudes, when you are shadowed from the radar. At
high altitudes, you are more likely to have a clear shot to the radar.

I think there is a balance between power and battery life.

I do not know the significance of the difference in altitude specification
between the two units. The manual clearly states that the maximum altitude
for the 175 watt unit is 15,000 feet. It would be necessary to understand
the reason for this statement before it is prudent to ignore it. It may be
regulatory, rather than technical.

Colin

It is possible that the 175 watt unit is only certified to 15,000', and
it would be illegal to use it above that altitude.

It is possible that the 175 watt unit is only certified to 15,000', and it
would be illegal to use it above that altitude.

That is my guess.

Paul Remde

COLIN LAMB wrote:


I do not know the significance of the difference in altitude specification
between the two units. The manual clearly states that the maximum altitude
for the 175 watt unit is 15,000 feet.

What's confusing is the manual (dated Aug 15, 2001) for my 175 watt
Becker unit states it's good to 35,000 feet. Specifically:

"Operating altitude 35000 ft. in accordance with EUROCAE/RTCA
ED-14D/DO-160D Cat. C1"

This is a unit purchased in Aug 2001. The manual just downloaded from
the Becker-USA site (dated Jan 15, 2002) shows the 15,000' altitude.

Time to call Becker, I think.

--
Note: email address new as of 9/4/2006
Change "netto" to "net" to email me directly

Eric Greenwell - Washington State, USA

"Transponders in Sailplanes" on the Soaring Safety Foundation website
www.soaringsafety.org/prevention/articles.html

"A Guide to Self-launching Sailplane Operation" at www.motorglider.org

If you read what Becker has listed, they "recommend" the higher powered
transponder at altitudes above 15K.......
they "recommend" only, there is no specific rule or regulation the
"required" the higher power unit above this altitude.
There have been no issue anywhere that I have encountered that specifically
states or stated that the 175W transponder was illegal or inoperable at
higher altitudes...aside from a small cost difference the 250 W version does
require more operating power....and has been very unpopular for nearly all
applications
tim
Wings & Wheels
www.wingsandwheels.com

wrote in message
ups.com...
5Z wrote:
The operating manual for the Becker ATC 4401-1-xxx transponder has the
following specifications:
(http://www.beckerusa.com/products/de...4401-1-I+O.pdf)

Max. operating altitude :
- ATC 4401-1-175 15000 ft.
- ATC 4401-1-250 50000 ft.

and

Flight level code (mode C) ICAO coding system 100-foot steps from
- ATC 4401-1-175 -1000 to 31000 ft.
- ATC 4401-1-250 -1000 to 62700 ft.

Does anyone know what exactly this means? Is the 175W unit not really
usable in sailplanes that plan to fly in the USA in areas where one
would go above 15K?

-Tom
Tom,
The 175 replies with 175 watts & the 225 replies with 225 watts. I'm
thinking the 175 is made for little bug smashers like we fly & the 225
is something you'd put into your C-210 or Piper Malibu and such. The
175 I've got seems to make the big brown turd looking Southwest jets
kinda steer around my little glider even at 12-14k. I can make my 2
sets of batteries last about 6-7 hrs and still see 11.5 v in each set
(8ah each set). I see the reply light going even on the Whites. It
will even work up to 50,000' but it's only going to reply with 175 w.
The closer you are to the antenna the better they will paint you. The
more wattage you reply with the better and further they can paint you.
I'd think that TCAS would pick either one up easily at 5-10 miles. As
far as the steps go your encoder replies with pressure altitude in 100'
incriments reliably up to the certified alt's (and probably beond but
not certified).
Russ

Hi Tim,

That is very good information! Where did you read it?

Thanks,

Paul Remde

"Tim Mara" wrote in message
...
If you read what Becker has listed, they "recommend" the higher powered
transponder at altitudes above 15K.......
they "recommend" only, there is no specific rule or regulation the
"required" the higher power unit above this altitude.
There have been no issue anywhere that I have encountered that
specifically states or stated that the 175W transponder was illegal or
inoperable at higher altitudes...aside from a small cost difference the
250 W version does require more operating power....and has been very
unpopular for nearly all applications
tim
Wings & Wheels
www.wingsandwheels.com

wrote in message
ups.com...
5Z wrote:
The operating manual for the Becker ATC 4401-1-xxx transponder has the
following specifications:
(http://www.beckerusa.com/products/de...4401-1-I+O.pdf)

Max. operating altitude :
- ATC 4401-1-175 15000 ft.
- ATC 4401-1-250 50000 ft.

and

Flight level code (mode C) ICAO coding system 100-foot steps from
- ATC 4401-1-175 -1000 to 31000 ft.
- ATC 4401-1-250 -1000 to 62700 ft.

Does anyone know what exactly this means? Is the 175W unit not really
usable in sailplanes that plan to fly in the USA in areas where one
would go above 15K?

-Tom
Tom,
The 175 replies with 175 watts & the 225 replies with 225 watts. I'm
thinking the 175 is made for little bug smashers like we fly & the 225
is something you'd put into your C-210 or Piper Malibu and such. The
175 I've got seems to make the big brown turd looking Southwest jets
kinda steer around my little glider even at 12-14k. I can make my 2
sets of batteries last about 6-7 hrs and still see 11.5 v in each set
(8ah each set). I see the reply light going even on the Whites. It
will even work up to 50,000' but it's only going to reply with 175 w.
The closer you are to the antenna the better they will paint you. The
more wattage you reply with the better and further they can paint you.
I'd think that TCAS would pick either one up easily at 5-10 miles. As
far as the steps go your encoder replies with pressure altitude in 100'
incriments reliably up to the certified alt's (and probably beond but
not certified).
Russ