[Milsurplus] SCR-245, BC-223 PE-125-AX Vibrator Supply

[WA5CAB at cs.com]

Dave,

Don't let the 10 watt quoted power output figure mislead you.  Remember 
that the thing normally operates into a 15' whip antenna at frequencies as low 
as 2 MC.  Quite inefficient.  From the SCR-245-AX manual, total HV current 
in Voice at 550 VDC (presumably 14.2 VDC input) is 185 mA.  That's 101.75 
watts total input from the vibrator or dynamotor supply.  The PE-237 used with 
the BC-1306 and early AN/GRC-9 uses (depending upon Order #) 4 or 5 HV 
transformers and a single very large 5PDT vibrator.  Of course, it also has to 
operate on 6 VDC (which doubles the primary current that the vibrator has to 
switch compared to the PE-125-AX).

The SCR-245-AX manual gives 23 ADC as the peak input current at 14.2 VDC.  
Some of that is of course heater and relay current.  My recommendation, if 
you try to operate with only half of the supply working, is NOT to try to run 
it on 12-14 VDC.

In a message dated 04/06/2014 13:17:40 PM Central Daylight Time, 
arc5 at ix.netcom.com writes: 
> Does anyone have experience with the PE-125-AX
> vibrator power supply for the BC-223 transmitter?
> The thing has two identical vibrator supplies 
> which are connected in parallel on the B+ output.
> They have some heavy iron in them.
> This transmitter puts-out 10 watts- not much.
> In mine, one of the supplies has bad iron.
> I pulled the fuses and the vibrator on the bad side.
> The other side is operating well.
> 
> I can't imagine this 10W rig needs double the current
> that one of these supplies can source.
> Manual has no explanation.  
> Does anyone know why this unit has dual supplies?
> Does the BC-223 really need the extra current 
> or is it some kind of "redundancy" thing?
> 
> 73 DE Dave AB5S
> 

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