[Milsurplus] PU-18/A ???

[Mike Hanz]

WA5CAB at cs.com wrote:

>My understanding is that Naval aircraft of the period when the ASB was in 
>service had an engine driven 800 CPS generator, not an inverter.  Just as they 
>had 24 VDC generators.  Mike?
>

I think some of both, Robert.  The engine driven generator (NEA 
series...NEA-5 by the end of the war) had the disadvantage of pretty 
wide frequency variations unless the problematical constant speed clutch 
was used, so it appears that the Navy shifted more and more of the more 
sensitive loads (like radar) to the 800-1 inverters.  The 800-1 didn't 
maintain a very accurate 800 Hz frequency either, but at least it was 
fairly constant.  Eclipse made 'em both - 
http://aafradio.org/docs/800-1.htm has more on the inverter.  The PU-** 
nomenclatures seem to be used more by the AAF than the Navy - the same 
Eclipse 800-1 is also labeled PU-43/A with a USAAF tag down in my 
basement.  I don't have any documentation on a specific inverter being 
dedicated to a specific radio set, though it is of course always 
possible that there are such beasties, most likely in the radar area.  
They seem to be more associated with the airframe than a specific piece 
of avionics, which is why you don't see any references to them in the 
radio manuals.

73,
Mike