Battery Source

Jim Vincent wrote:
"Andy" wrote in message
oups.com...

If the battery is near death will it provide the current required by
the upconverter? It's not magic and you can't get more power out of
the upconverter than you put in. I'm curious to know if you have
measured the performance with a "battery near death"?

snip


Haven't tested near death, but actually was part of the thinking. If the
battery is near death, it has a little juice left. If the radio would not
tolerate a low voltage, then I could upconvert.

This is an interesting idea. By using 12 volts until the radio is close
to unsatisfactory operation, you avoid the efficiency losses in the
converter. At that voltage, you switch on the converter and make
available the rest of the battery's capacity, though with a 10%-15%
capacity loss in the converter. Still, you'd get 90+% of the battery's
capacity, instead of 50% (or wherever your radio becomes unsatisfactory).

This might be a solution for Udo, the original poster. I suggest he try
the Datel converter (UHE-15/2000-Q12) mentioned by Tom Seim, as it is
cheap, very small, totally enclosed, wide temperature range, and with
excellent specifications for regulation, ripple, and
overload/overvoltage protection. I can't guarantee it will work since I
don't know of anyone that's tried it in a glider, but it's the one I'd
get if I had Udo's problem. Of course, the converter would only be used
to power the radio, not the other instruments.

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Eric Greenwell
Washington State
USA

David Kinsell wrote:

The truth is virtually no aircraft radios have upconverters built into
them. They switch high currents at high voltage at low RF frequencies.
A nasty thing to be building into a radio with a sensitive receiver. The
converters put out harmonics from their high-power square waves going
well into the aircraft band.

I hadn't thought about the noise problem, but I can see it would be an
issue. If they don't use converters, how do the newer radios manage so
well on low voltages? For example, the Becker AR4201 is specified for 2
watts output at 10 volts, and the Dittel FSG 2T is specified from 11 to
16 volts, with 9 to 11 volts emergency operation. Too bad the
Becker/Dittel engineers don't follow ras, but it does free them to
design more stuff for us.

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Eric Greenwell
Washington State
USA

"Eric Greenwell" wrote in message
...
Jim Vincent wrote:
"Andy" wrote in message
oups.com...

If the battery is near death will it provide the current required by
the upconverter? It's not magic and you can't get more power out of
the upconverter than you put in. I'm curious to know if you have
measured the performance with a "battery near death"?

snip


Haven't tested near death, but actually was part of the thinking. If the
battery is near death, it has a little juice left. If the radio would
not tolerate a low voltage, then I could upconvert.

This is an interesting idea. By using 12 volts until the radio is close to
unsatisfactory operation, you avoid the efficiency losses in the
converter. At that voltage, you switch on the converter and make available
the rest of the battery's capacity, though with a 10%-15% capacity loss in
the converter. Still, you'd get 90+% of the battery's capacity, instead of
50% (or wherever your radio becomes unsatisfactory).

This might be a solution for Udo, the original poster. I suggest he try
the Datel converter (UHE-15/2000-Q12) mentioned by Tom Seim, as it is
cheap, very small, totally enclosed, wide temperature range, and with
excellent specifications for regulation, ripple, and overload/overvoltage
protection. I can't guarantee it will work since I don't know of anyone
that's tried it in a glider, but it's the one I'd get if I had Udo's
problem. Of course, the converter would only be used to power the radio,
not the other instruments.

--
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Eric Greenwell
Washington State
USA

I'm a little concerned about hitting the system with 15V. Be sure to check
the voltage operating ranges of all your gear. If you find you're
constrained to a lower voltage, you then have two options. First, get the 15
V model and use the trim function to bring it down by 5% to 14.25 V or
secondly use a 12 V model trimmed up to by 5% to 12.6 V. The trim is easily
configured using resistors or potentiometers.

Jim Vincent wrote:

This might be a solution for Udo, the original poster. I suggest he try
the Datel converter (UHE-15/2000-Q12) mentioned by Tom Seim, as it is
cheap, very small, totally enclosed, wide temperature range, and with
excellent specifications for regulation, ripple, and overload/overvoltage
protection. I can't guarantee it will work since I don't know of anyone
that's tried it in a glider, but it's the one I'd get if I had Udo's
problem. Of course, the converter would only be used to power the radio,
not the other instruments.


I'm a little concerned about hitting the system with 15V. Be sure to check
the voltage operating ranges of all your gear. If you find you're
constrained to a lower voltage, you then have two options. First, get the 15
V model and use the trim function to bring it down by 5% to 14.25 V or
secondly use a 12 V model trimmed up to by 5% to 12.6 V. The trim is easily
configured using resistors or potentiometers.

Yes, 14.25 should be fine, since a fully charged 14 volt battery is
almost 15 volts.


--
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Eric Greenwell
Washington State
USA

Eric Greenwell wrote:
David Kinsell wrote:

The truth is virtually no aircraft radios have upconverters built into
them. They switch high currents at high voltage at low RF
frequencies. A nasty thing to be building into a radio with a
sensitive receiver. The converters put out harmonics from their
high-power square waves going
well into the aircraft band.

I hadn't thought about the noise problem, but I can see it would be an
issue. If they don't use converters, how do the newer radios manage so
well on low voltages? For example, the Becker AR4201 is specified for 2
watts output at 10 volts,

I don't know where you saw that. On their web site, they list the input
voltage as 12.4 to 15.1 volts, with emergency operation only down to 10
volts.


and the Dittel FSG 2T is specified from 11 to
16 volts, with 9 to 11 volts emergency operation.

Yep. In their literature, they also say you must have at least 11.0
volts during transmit.

Sounds like two radios designed for 14 volt operation, just like always.
I wonder how long a 12 volt battery mounted in the tail is going to
supply 12.4 volts to the Becker?? 10 minutes maybe, if you've got good
wiring?? I expect Becker is just a little more honest with their specs,
rather than really being different than the Dittel.


Too bad the
Becker/Dittel engineers don't follow ras, but it does free them to
design more stuff for us.

You've got to keep in mind the soaring market is peanuts compared to
the power market, so that's why radios have been, and still today are
designed to the 14 volt standard. Why put a switching converter in
a radio that's sitting there all day long with a well-regulated, very
stout 14.2 volt supply?

-Dave

Paul Remde wrote:
Hi,

It is my belief that all the work required to make an "upconverter" will
lead to only minimal increases in your radios transmit power (10 to 20%?).
It doesn't seem worth it to me. I vote 12V.

Paul Remde


10-20%??? A discharged 12 volt battery is going to be around 10.5 volts,
with maybe half a volt lost in the wiring and fuses. The upconverter can
comfortably be set to 15 volts. The RF voltage follows the supply, so
it'll be 50% higher. Since the power is the square of the voltage, you're
looking at more than double the transmit power.

But the power isn't the big issue, it's the distortion you get at lower
voltage. Many radios sound really bad on transmit at 11 volts, and shut
down entirely at about 10 volts. Since they're 14 volt radios, that shouldn't
be surprising, should it? I just wish glider pilots had to listen to their
own transmissions, there's some really bad sounding radios on the air.

Upconverters aren't a bad idea, except for the potential for interference in
the cockpit. It's kind of a silly misuse of technology to be using something
like this, when it's so easy to get the proper voltage from a battery. I've
got nothing against them, I've designed them into commercial products where
appropriate, but this just isn't the best place for them.

-Dave

Andy wrote:
It's probably also worth noting that a 14volt pack hot off the charger
has a terminal voltage greater than 15 volts and will exceed the
maximum voltage specs for many modern glider systems.

Andy


Maybe for a few minutes, if you take it off the charger and run to
the plane and immediately install it and turn it on. I've never
seen more than 14.8 volts with a more normal installation.

If you read your manuals, avionics have max voltages of 16 or 16.5
volts, so it doesn't seem to be an issue.

-Dave

David Kinsell wrote:

I hadn't thought about the noise problem, but I can see it would be an
issue. If they don't use converters, how do the newer radios manage so
well on low voltages? For example, the Becker AR4201 is specified for
2 watts output at 10 volts,


I don't know where you saw that. On their web site, they list the input
voltage as 12.4 to 15.1 volts, with emergency operation only down to 10
volts.

It's in the manual, page 1-3.

and the Dittel FSG 2T is specified from 11 to 16 volts, with 9 to 11
volts emergency operation.


Yep. In their literature, they also say you must have at least 11.0
volts during transmit.

A 12 volt battery can put out 11 volts.


Sounds like two radios designed for 14 volt operation, just like always.

Not "just like always": The older radios can't come close to the specs
for these radios.

I wonder how long a 12 volt battery mounted in the tail is going to
supply 12.4 volts to the Becker?? 10 minutes maybe, if you've got good
wiring?? I expect Becker is just a little more honest with their specs,
rather than really being different than the Dittel.


Too bad the Becker/Dittel engineers don't follow ras, but it does free
them to design more stuff for us.


You've got to keep in mind the soaring market is peanuts compared to
the power market, so that's why radios have been, and still today are
designed to the 14 volt standard.

Except handhelds, of course, of which tons are sold. Maybe some of that
design technology is creeping into the panel mounts.

Why put a switching converter in
a radio that's sitting there all day long with a well-regulated, very
stout 14.2 volt supply?

Because it's easy to do? Because the generator might quit? Because you
can sell a few more radios to folks like us? I keep hoping an engineer
with some detail design knowledge of these radios will hop in here and
tell us, but no luck yet.

--
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Eric Greenwell
Washington State
USA

Actually.the Walter Dittel FSG2T and previous models FSG70/71 do in fact
have some more sophisticated circuitry that does allow it to operate at a
lower voltage than the Becker does and both are a bit more sophisticated
than others like Avionic Dittel, Filser and Microairs (just to name a few).
Any of these radios will operate at lower voltages at some reduction in TX
output power.but all have more than enough Tx power for our purposes
anyway....you will notice at very low voltages microphone audio becoming
distorted as a first indication that the input voltage has depleted too far
and though at this point it's already too low a battery capacity and will
soon become worthless anyway.......and at that point only PFM would allow it
to function acceptably, it becomes rather relative.no battery left..no radio
tim

Wings & Wheels
www.wingsandwheels.com


"David Kinsell" wrote in message
...
Eric Greenwell wrote:
David Kinsell wrote:

The truth is virtually no aircraft radios have upconverters built into
them. They switch high currents at high voltage at low RF frequencies.
A nasty thing to be building into a radio with a sensitive receiver.
The converters put out harmonics from their high-power square waves
going
well into the aircraft band.

I hadn't thought about the noise problem, but I can see it would be an
issue. If they don't use converters, how do the newer radios manage so
well on low voltages? For example, the Becker AR4201 is specified for 2
watts output at 10 volts,

I don't know where you saw that. On their web site, they list the input
voltage as 12.4 to 15.1 volts, with emergency operation only down to 10
volts.


and the Dittel FSG 2T is specified from 11 to 16 volts, with 9 to 11
volts emergency operation.

Yep. In their literature, they also say you must have at least 11.0
volts during transmit.

Sounds like two radios designed for 14 volt operation, just like always.
I wonder how long a 12 volt battery mounted in the tail is going to
supply 12.4 volts to the Becker?? 10 minutes maybe, if you've got good
wiring?? I expect Becker is just a little more honest with their specs,
rather than really being different than the Dittel.


Too bad the Becker/Dittel engineers don't follow ras, but it does free
them to design more stuff for us.

You've got to keep in mind the soaring market is peanuts compared to
the power market, so that's why radios have been, and still today are
designed to the 14 volt standard. Why put a switching converter in
a radio that's sitting there all day long with a well-regulated, very
stout 14.2 volt supply?

-Dave

As an aside--I have a Dittel FSG71M in the portable base station case(the PS
model) with battery and charger built in. It works very nicely. It has a 12v
7.5 ah battery---factory designed and integrated. This is a "spare no
expense" outfit and I think the Dittel engineers would make it any voltage
they wanted.

--
Hartley Falbaum
"Tim Mara" wrote in message
...
Actually.the Walter Dittel FSG2T and previous models FSG70/71 do in fact
have some more sophisticated circuitry that does allow it to operate at a
lower voltage than the Becker does and both are a bit more sophisticated
than others like Avionic Dittel, Filser and Microairs (just to name a
few). Any of these radios will operate at lower voltages at some reduction
in TX output power.but all have more than enough Tx power for our purposes
anyway....you will notice at very low voltages microphone audio becoming
distorted as a first indication that the input voltage has depleted too
far and though at this point it's already too low a battery capacity and
will soon become worthless anyway.......and at that point only PFM would
allow it to function acceptably, it becomes rather relative.no battery
left..no radio
tim

Wings & Wheels
www.wingsandwheels.com


"David Kinsell" wrote in message
...
Eric Greenwell wrote:
David Kinsell wrote:

The truth is virtually no aircraft radios have upconverters built into
them. They switch high currents at high voltage at low RF frequencies.
A nasty thing to be building into a radio with a sensitive receiver.
The converters put out harmonics from their high-power square waves
going
well into the aircraft band.

I hadn't thought about the noise problem, but I can see it would be an
issue. If they don't use converters, how do the newer radios manage so
well on low voltages? For example, the Becker AR4201 is specified for 2
watts output at 10 volts,

I don't know where you saw that. On their web site, they list the input
voltage as 12.4 to 15.1 volts, with emergency operation only down to 10
volts.


and the Dittel FSG 2T is specified from 11 to 16 volts, with 9 to 11
volts emergency operation.

Yep. In their literature, they also say you must have at least 11.0
volts during transmit.

Sounds like two radios designed for 14 volt operation, just like always.
I wonder how long a 12 volt battery mounted in the tail is going to
supply 12.4 volts to the Becker?? 10 minutes maybe, if you've got good
wiring?? I expect Becker is just a little more honest with their specs,
rather than really being different than the Dittel.


Too bad the Becker/Dittel engineers don't follow ras, but it does free
them to design more stuff for us.

You've got to keep in mind the soaring market is peanuts compared to
the power market, so that's why radios have been, and still today are
designed to the 14 volt standard. Why put a switching converter in
a radio that's sitting there all day long with a well-regulated, very
stout 14.2 volt supply?

-Dave