Transponders

"Eric Greenwell" wrote in message
...
Kirk Stant wrote:

For a lot of people, it's $900+, which is about half the cost of
a transponder installation. When I look at it that way, I'm buying many
years of "insurance" for a one-time fee that is two years of hull
insurance.

Your "cost" seems a little low for the "total cost" of a transponder,
encoder, extra battery, and installation. Also, your
"one-time fee " should include the cost of recertification every 24 months
which could be around $200. That might be between 10% to 30% of the annual
hull insurance (depending on hull value).

Duane

Duane Eisenbeiss wrote:
"Eric Greenwell" wrote in message
...

Kirk Stant wrote:


For a lot of people, it's $900+, which is about half the cost of

a transponder installation. When I look at it that way, I'm buying many
years of "insurance" for a one-time fee that is two years of hull

insurance.

Your "cost" seems a little low for the "total cost" of a transponder,
encoder, extra battery, and installation.

It will be larger if you have to install another battery and pay someone
to do the total installation, but a lot of people will be able to use
the battery they have and do the installation themselves (proper
signoffs required, of course). A Microair + encoder + antenna is about
$1800 from your favorite soaring supplier.

Also, your
"one-time fee " should include the cost of recertification every 24 months
which could be around $200. That might be between 10% to 30% of the annual
hull insurance (depending on hull value).

A VFR check is about $50-$70; IFR certification is much more stringent
and is $150-$300. Hardly anyone will want to fly their glider IFR, but I
know at least one pilot that does (not IMC, but on IFR flight plans).

I decided to install one after seeing too many airliners too close.
Anyone that feels that way about their flying should look into
installing one, because it's not as costly they likely think it is. My
articles in the Febuary and March 2002 Soaring covered things in much
more detail than I can here.

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Eric Greenwell
Washington State
USA

From what I can gather, the low-power transponders are 400mA
and encoder 200mA at about 12 volts.

The microfilm superthin solar panels about 1 foot square (12" by 12")
advertise 600mA at about 12 volts.

Sadly, the solar panels in my experience don't put out rated power
on typical days, with less than ideal sun angles (maybe really only
putting out 25%).

Also, I suspect transponders underrate their power consumption,
and if flown in high jet traffic areas (where they get
pinged by ATC and the jets), probably consume quite a bit more.

So really one might be looking at 8 square feet of solar
array just for a transponder! Maybe a little hard to
implement on a glider without using the wing surfaces,
and the caveats that entails...

Well, it was a nice thought...

"Mark James Boyd" wrote in message
news:40140af4$1@darkstar...
From what I can gather, the low-power transponders are 400mA
and encoder 200mA at about 12 volts.

The microfilm superthin solar panels about 1 foot square (12" by 12")
advertise 600mA at about 12 volts.

Sadly, the solar panels in my experience don't put out rated power
on typical days, with less than ideal sun angles (maybe really only
putting out 25%).

Also, I suspect transponders underrate their power consumption,
and if flown in high jet traffic areas (where they get
pinged by ATC and the jets), probably consume quite a bit more.

So really one might be looking at 8 square feet of solar
array just for a transponder! Maybe a little hard to
implement on a glider without using the wing surfaces,
and the caveats that entails...

Well, it was a nice thought...

That's today, tomorrow may well be different.

http://www.lbl.gov/Science-Articles/...olarcells.html

http://www.scienceagogo.com/news/200...runc_sys.shtml

or this

http://www.californiasolarcenter.org...0030128-6.html

Perhaps someday be able to shoot a top coat that will take care of keeping
the batteries up. There's work being done at the nanotech level to make
these much more efficient. Imagine the diversity of applications, roofing
materials, car finishes, clothing, tents, aircraft, boats, etc.

Frank Whiteley
Colorado

The situation isn't nearly so gloomy!

Mark James Boyd wrote:
From what I can gather, the low-power transponders are 400mA
and encoder 200mA at about 12 volts.

My Becker and ACK encoder ~ 410 ma with no replies, and less than 500 ma
even in southern California airspace. A 5 hour flight is 2.5 amphour,
leaving lots of juice for the other instruments on the typical 7 ah battery.


The microfilm superthin solar panels about 1 foot square (12" by 12")
advertise 600mA at about 12 volts.

Sadly, the solar panels in my experience don't put out rated power
on typical days, with less than ideal sun angles (maybe really only
putting out 25%).

Put two on! But even one, with your assumption, means the battery has to
supply 1.7 ah to the battery, leaving ~ 5 ah in the battery for other
purposes. With two supplying 300 ma, the net transponder usage is only 1 ah!


Also, I suspect transponders underrate their power consumption,
and if flown in high jet traffic areas (where they get
pinged by ATC and the jets), probably consume quite a bit more.

Not true for the Becker. Ask a Microair owner about it's consumption.

So really one might be looking at 8 square feet of solar
array just for a transponder! Maybe a little hard to
implement on a glider without using the wing surfaces,
and the caveats that entails...

The Strobl panels used by the German manufacturers are very efficient
(http://www.strobl-solar.de/ - use the Google translation tools) and can
supply enough with less than 2 square feet. The disadvantage is the
cost, so most people would probably opt for another, or bigger, battery.


Well, it was a nice thought...

It _is_ a nice thought! People are doing it - it works!

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Eric Greenwell
Washington State
USA