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

[Doran Platt]

Concur with Wayne... internal supplies better than internal, when all's said and done.  I prefer NOT to re-wire the filament circuit as it buggers the dial light dimmer circuit.  I use a 24v control transformer and it works out fine.  Not have having to switch dynamotor current, one section of the function switch can be re-purposed as a power switch.  Also there is no limitation to space.  Also concur with B+_ consideration. Anything from 170 to 220v is just fine. More simply introduces issues, especially if the unit has not been re-capped. But, that is another story.  BTW, the original rear panel power/control plug can be replaced with a Jones "Gonset" 12 pin plug. Form and fit are near perfect.
Jeep K3HVG

>     On 08/08/2022 1:53 PM releazer at earthlink.net wrote:
> 
> 
> 
>     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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