Another Mystery Transformer

[KE6DF]

Does anyone have an old enough UTC transformer catalog that has specs on a PA-913 transformer?

It's a smallish plate + filament transformer.

All the old catalogs I can find on the net don't have this part number.

If anyone can find a catalog that does, please post the URL.

Thanks

Dave

[Opcom]

I am not aware of 3-digit PA series in the 900's. I did look through every UTC catalog and UTC cookbook in the bunker, no joy.  It might have been translated to a CG series later but was not found either keying on 913.

[KE6DF]

Thanks for the effort.

I bid for that transformer on ebay.

And won it for 99 cents. No one else bid.

Sometimes ebay listers get the part number wrong, so when it arrives I'll check.

The picture shows a 115V primary, 5v, 6.3v, and 2.5V secondaries plus one additional secondary marked HV.

I can hook it up and measure the hv and, given the size and weight, guess the current ratings.

It probably is some kind of small power transformer for a receiver or audio preamp or something like that.

Anyway, it should be worth 99 cents.

Perhaps it is an OEM special order product.

[k4kyv]

Perhaps it is an OEM special order product.

UTC usually assigned an arbitrary 5-digit number to those.

[Opcom]

I wonder if it is an oscilloscope power transformer - -with the 2.5V for a HV vacuum rectifier. You can tell because you will have the regular type of CT winding, then one extra lead that has high resistance continuity to the CT but more volts, like 900-1500. Usually rated <1mA for the CRT.

Pls. let us know when you get it in!

[KE6DF]

Great guess.

I got it and tested it just today.

I hooked it up to a filament transformer and put 6v into the 115v primary.

I got out 54v from the HV secondary terminals 27v each side of ct.

So that works out to about 1KV. Nearly 3200 ohms DC resistance accross the whole secondary, so it can't deliver much current.

Not sure what use it will be, but I can at least use it as a small filament transformer.

Dave

[Opcom]

I think the 2.5V is the HV rectifier and 6.3V is the CRT cathode, well insulated, not much current from either winding. Time to do the test where you load it till it drops 10% and that is the current rating..