[ARC5] BC-669 Vet Project: PE-110 Power Supply

[J Mcvey]

Dave, I used your book to trace it back,and sure enough , pins F and K are shown as "AC line" on the interconnect diagram ( page 20 or the book). PL2 ultimately connects to PL6 of the power supply. Obviously you have found an ancient error in  this schematic . Otherwise it doesn't compute. 
The thing has a vibrator too?

   On Tuesday, September 24, 2019, 3:24:51 PM EDT, Brooke Clarke <brooke at pacific.net> wrote:  
 
  Hi Dave:
 
 Printed page 10, paragraph 4 "Source of power and power requirements ....During stand-by periods the receiver will operate from 12 volts direct current supplied by the storage battery in Power Unit PE-108-(*)."  So it would make sense that the antenna relay would run from 12V so the system will work as a receiver without the 115 VAC supply (generator).
 
 But . . . page 32 Rx schematic shows RY1 as being normally closed, so with no power applied you have Rx function.  So the reason for giving it a 12 VDC coil may have to do with parts availability or some non functional reason?
 
 Page 32 tracing the RY1 coil through SO1 (pins 1 & 3) back through the system to the source seems difficult (will require printing the schematics and color coding the traces) (PS making all grounds heavy black and B+ red sure simplifies a schematic).  But PE-108 contains a lot of 12 Volt battery power that's routed to PE-110 and I'm guessing is on the CD-515 (pg 20) wire labeled "receiver filament" so is available throughout the system.  Page 32: BC-699 V8 and V9 (VT-100 = 807) have their 6V filaments connected in series so the filament supply is probably 12V.  I say probably because they are on SO1 pin 5, not 1&3, so more mystery.
 -- 
Have Fun,

Brooke Clarke
https://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html
axioms:
1. The extent to which you can fix or improve something will be limited by how well you understand how it works.
2. Everybody, with no exceptions, holds false beliefs.
 -------- Original Message --------
  
 

Re: BC-669 Mystery Relay.
 For those, like me, scratching their heads over why the factory installed a 12VDC Antenna/TR relay in place of a 115VAC relay, here is a link to the manual:
 
 BC-669 Manual 1944
 
 The PE-110 power supply, which fits at least the -A, -B, -C, -AM, -BM, -CM models (the most common).  The PE-110 supply is on page 25.  VP-1 is a vibro-pack to provide Receiver B+ from 12 VDC battery, but not Transmit power.  That's strictly 115VAC, so a 12 VDC TR relay is strange.  PL2 on the Modulator deck mates to PL6 on the power supply.
 
 73 DE Dave AB5S
 

 
 
 
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