[ARC5] APR-4

[J. Forster]

The APR-1 was used on at least one sub, LIONFISH, where space is very
tight. Bigger ships used the RDO. I have a pic, if you want.

-John

===============



> "OK, a dumb question:  Why would some models of the APR-4(*) be configured
> to work with 60 cps power?  Mine does, works great.  But why/where??"
>
>
> The older WWII models used bigger and heavier transformers that would work
> on 60 HZ and therefore would also work on 400 HZ.  I would suspect that
> they wanted to be able to use the gear shipboard as well.
>
> The postwar models, the APR-4Y, 1950 is the date on mine, reduced the
> weight by going to 400 HZ transformers.  By that time, 400 HZ was getting
> pretty common on at least larger aircraft.  By the late 50's 400 HZ was
> common on even single seat fighter jets.  This was because the Constant
> Speed Drives used with jet engines were built to accommodate 115V 400 HZ
> alternators as well as 28 VDC generators.
>
> On the U-2, to save weight they dispensed with the CSD and drove the 400
> HZ alternator directly off the engine.  This meant that the alternator
> only produced the correct voltage and frequency at the designed engine
> speed, at long range high altitude cruise, but that was not a problem,
> since the avionics that needed it really only had to work during that
> portion of the flight, anyway.
>
> Wayne
> ______________________________________________________________
> ARC5 mailing list
> Home: http://mailman.qth.net/mailman/listinfo/arc5
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:ARC5 at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>
>