[Milsurplus] power requirements

[WA5CAB at cs.com]

I thought that by now someone would have popped up with an answer.  But I 
quess everyone else felt the same way as I did.  Just about everyone on the 
planet has the schematic of a Command Set receiver.

However, the 46104 is wired the same way and has the same power requirements 
as any other ARA or SCR-274-N receiver.  Probably a bzillion places on the 
internet where the schematic and information (or in some cases disinformation) 
has been posted.  About 30% of them will be wrong in one respect or another but 
if you look at ten and take the seven that agree you'll probably have it 
right.

But briefly, power requirements (in original spec) are 250 VDC @ around 45 
mA.  Dynamotor was rated 60 mA but had some reserve in order to operate aux 
gear.  And 24-28 VDC @ .45 mA for the filaments.  If you run the receiver off of 
the original dynamotor, you need 24-28 VDC @ 1.55 A.

Wiring to the rear connector is 

pin 1 ground/minus
pin 2 600 ohm audio (in ARA - in early SCR-274-N impedance is 4000).
pin 3 gain control (ground for max)
pin 4 CW Osc Shut Off (ground for off)
pin 5 +Screen Voltage (not used)
pin 6 +28 VDC
pin 7 +250 VDC (not normally used but you can power the receiver into it)  

And a tip, do not ever under any circumstances ever solder to any of the male 
mini-banana pins.  From the standpoint of destroying the receiver, you might 
just as well drill holes all over it.  The sockets can be drilled out 
successfully without too much trouble or danger of permanent damage.  The pins are 
virtually impossible to desolder to the point where they will function again.  
The 1.5-3.0 MC ARA is the 2nd rarest.  

Another tip - if you have a junker receiver chassis, you can remove one of 
the 6-pin plugs that the IF cans plug onto (in later production, some don't have 
all the pins), rob one of the unused (no solder) pins from one of the RF can 
plugs and install it in the center of the plug you removed, and have a male 
plug that mates with the rear connector.  An early chassis will yield parts for 
three such plugs.

In a message dated 11/23/2007 6:45:47 PM Central Standard Time, 
wb9nwn at sbcglobal.net writes: 
> any one of you fellas have the pin out and voltage
> requirements for a cct-46104 receiver? you can mail me
> direct at: wb9nwn at sbcglobal.net thanks!

Robert & Susan Downs - Houston
<http://www.wa5cab.com> (Web Store)
MVPA 9480
<wa5cab at cs.com> (Primary email)
<wa5cab at comcast.net> (Backup email)
   
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