[ARC5] power supplies

[Kenneth G. Gordon]

On 9 Aug 2014 at 13:16, john rose wrote:

> I routinely go through the classified listings at QTH.com and some interesting
> goodies show up. In this case a pair of ARC-5 power supplies that plug into the
> dynamotor space on receivers.
> 
> http://swap.qth.com/view_ad.php?counter=1134476

I once had quite a number of power supplies which were built and sold by 
Fair Radio Sales. These were all built on dynamotor bases, and used 
transformers which Fair had especially built for the purpose.

Output was around 250 VDC under load, and 24 VAC for filaments.

Their earlier versions used a 5Y3 rectifier tube, but they shortly changed to 
solid-state diodes.

I sold all I had but two, which I kept for testing purposes. I "refurbished" 
those before I sold them.

Fair also made and sold units which simply plugged into the power/control 
connector on the rear of the receiver. These were housed in small 
gray-painted cabinets, used the same transformers as their 
dynamotor-based ones, and included a 4" speaker, a pilot light, a BFO 
switch and a "volume" control.

I still have two of those also, but haven't used either one for some time. They 
take up too much bench space, of which I have so little.

My own receiver power supplies now consist of two Radio Shack 110VAC to 
24VAC CT transformers, connected back to back, with a very well-filtered 
voltage-doubler on the "output" of the backwards transformer. These provide 
about 225 VDC, and either 12 VAC or 24 VAC, switchable, for filaments. I 
connect these to the receiver through an old dynamotor base as the 
"connector".

They work very well, and run cool.

Ken W7EKB