[GreenKeys] inexpensive loop supply transformer wanted

[epvgk at limpoc.com]

On Sat, Dec 21, 2013 at 09:53:58AM -0600, Jim Sheldon wrote:
> These are getting harder and harder to find.  One solution I've used in the past was to pick up a couple of 120 to 12 volt, 2 amp filament or power supply transformers.  Connect the 12 volt secondaries of the two transformers together.  T1 will step down to 12 volts from 120 and T2 will take that 12 volts back up to 120.  AC in to one primary and take the 120 out for the loop supply from the other primary.  Kinda hokey but it does work and 120:12 volt transformers are still pretty cheap from lots of places.
> 
> One in particular I use a lot is Marlin P. Jones associates out of Florida someplace.  Their website is www.mpja.com
> 
> Jim - W0EB

This is overkill for a loop supply, but I picked up one of these variable DC 
supplies recently. Enough current to run multiple loops with separate resistors,
and even run the punch on a M19. 

http://www.aliexpress.com/item/0-150V2A-Power-Supplies-AC-DC-POWER-Batter-Charger/756203566.html

I usually avoid buying from anonymous chinese vendors like this but I figured 
I'd take a chance - it's actually quite good. Useful adjustment range is around 
60 to 165 VDC via a 10+ turn trimmer, output is fairly clean and it doesn't produce 
much RF hash. 

eric