[Milsurplus] SCR522/542 was Kluge conversion of 24 volt dynamotors to 12 ...

[WA5CAB at cs.com]

Actually, it's a little more complicated than that in the PE-94, although I 
have no idea why.  I was in a hurry a while ago (my wife had just had about 
65 items sell on eBay and we were supposed to be busy packing them)  and 
didn't include all of the details.  In the PE-98-(*) the carbon pile regulator 
keeps the output of the LV generator winding at 13 volts.  In the PE-94-(*) 
there is a resistor 317 between the generator winding and the regulator and 
line going to the radio.  The regulator keeps the voltage downstream of the 
resistor at 13 volts but the dynamotor LV output actually runs at 14.5 
volts.  The resistor is not present in the PE-98.

The 12.35 to 13.52 volt range is what the book gives as worst case 
regulator oscillatory range after turn-on or other large change in loads.

In a message dated 7/19/2009 4:55:25 PM Central Daylight Time, 
scr287 at sbcglobal.net writes: 
> To be absolutely correct, the book says the filament supply
> in the radio proper is 13 Volts.
> 
> One reason for the apparent complexity of running the filaments
> from a dynamotor winding, is that both the 28V PE-94 and 14V
> PE-98 have a carbon pile regulator in them, that senses the 13V output
> and adjusts dynamotor speed accordingly.
> 
> According to the book, the output variation is 12.35 to 13.52 Volts.
> 
> Jack Antonio WA7DIA

Robert Downs - Houston
wa5cab dot com (Web Store)
MVPA 9480