Staco Variable
Transformer ( Variac )
Click for larger photo.
I found this unit for $30.00 at the 2005 Indianapolis Hamfest. The
ammeter is a NOS Simpson that I also found at the same hamfest. I
attached it to the variac using a standard 4"x 4"x 2 1/8" electrical
box. My variac has a input rating of 120v, 50/60 hz and a output rating
of 0 - 120/140 volts @ 10A, 1.4 KVA.
This would be what I consider a must for anyone
planning on repairing or working on antique radios. I use it
mostly when first powering up a radio, I can slowing increase the
voltage and observe the amperage draw. This gives me more control of
things if a short develops, potentially saving valuable components. I
wish I would have had one of these years ago when a 6X5 GT rectifier in
my Zenith 8-S-463 shorted while I was powering it up, cooking the power
transformer and several other components.