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

[Mike Kana]

Thanks for all the input. I’ve made an “executive decision” that the PSU reside 
outside the radio and I find a cinch jones plug for the wiring harness
I have 24-28 volt supplies and will come up with a B+ that won’t stress
the innerds. I have to see what the B+ is on the home brew supply
It would be nice if the currrent consumption was low enough I could
get away with the trick I do with my ARC 5 receivers which is to
use a daisy chain of 9v batteries to get to 180-200v
Thx 73
Mike

Warning!  This is transmitted over a non secure medium

> On Aug 8, 2022, at 3:38 PM, JAMES FALLS <radio-tuber at att.net> wrote:
> 
> I built a dedicated variable LV PSU that tops out at 135VDC for use with a BC-342 and 314. Do you think this could work for a ‘348? I want to give those old parts a break. I found the 342 to run cool with only minor drift at LV between 90-120V. 
> 
> Jim Falls K6FWT 
> 
>>> On Aug 8, 2022, at 11:59, Don Sanders <w4bws1 at gmail.com> wrote:
>>> 
>> 
>> I found small transformers at Home Depot used for control voltage on the furnace, I believe. 24 volts at about 2 amps and $12.00. I used two to make a PS for my BC455. Should be good for other filament used also.
>> Dr. Don W4BWS
>> God Bless All
>> 
>> 
>> 
>> 
>>> On Mon, Aug 8, 2022 at 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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