[ARC5] Replacement power xformer for a BC348 or other mil receivers

[releazer at earthlink.net]

I only own eight BC-348 receivers and two BC-342's, but in my opinion you'd be better off building a separate external power supply.

One BC-348 I bought worked right out of the shipping box and examination revealed that a previous owner had followed the Surplus Conversion article exactly, using a 300V B+ transformer with separate 6V and 5V filaments windings, a 5Y3 and  a classic capacitor and choke filter.  Even without replacing the 5Y3 with solid state rectifiers this still left the B+ much too high.  The BC-348 used 220VDC from the dynamotor and will run happily with a lot less and with less stress.  I added power resistors in both the AC line and the B+ line to get the voltage down to about 200 VDC and rebuilt the mounting plate for the internal power supply into something less likely to produce a disaster.  They had used the original dynamotor mounting plate for the power  supply and I replaced that with an AL plate so I could create a dynamotor pack some day; hope you are as lucky.  Unfortunately they had used the original front panel ON-OFF switch for the AC line and I did not like that much, installing a inline switch on the new power cord.  

Good luck!

Wayne
WB5WSV         
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