Help with any info on this T

[angelodp]

Was given this T a while back. I need to buzz it out. Anyone familiar with this item. I do not find any useful info on the net.

[Stevem]

Looks like a PT out of a Osscilscope

The filiment voltages might not be useful, but if it was out of a CRT based O-scope then it's available V+ current might be enough for a single ended class A output stage or two a 6aQ5 class A/B deal

[angelodp]

O'scope? Wow this thing weighs ten pounds!!

[Stevem]

Well it's hard to judge mass with nothing in that photo to provide scale.

[Phil_S]

It looks like the T has 6 or 7 pairs. If you can identify the primary, plug it in and see what comes out on the various secondaries. I'm thinking it could be a good item to keep on the bench for use in some kinds of testing. It is possible that the pairs are for separate windings, which is a good thing. I'm doubtful it's good for an amplifier. I haven't built anything for quite a few years, but keep a big one similar to that on the bench. At 10 pounds it must be capable of supporting a considerable amount of current. Check the recent thread on unknown transformers. Good luck!

[angelodp]

Hi Phil, it has 6 on one side and 9 on the other. I started buzzing it and got sidelined.

[angelodp]

No heavy gauge wire, so I doubt there will be either 6.3v or 5v windings present. So maybe a bench type device at best.

[R.G.]

There was a pretty good run down on how to measure an orphan transformer in some recent transformer threads. You might give those a read.

[angelodp]

Yes R.G. on it. Will give a detailed update.

[Phil_S]

Best not to pre-judge what secondary supplies are there. If you find several of the same voltage, it is possible to hook up in parallel which will add the current capacity. You might also hook up windings in series, which will allow you to create a variety of actual secondary voltages. The risk, as you note, is that each winding may have been wound with light gauge wire meaning it has a "light" current capacity. As I noted before, it might be a good candidate for a bench supply.

As you might guess, I find this sort of thing to be very interesting. I hope you'll post what you find including output voltage and DCR for each winding.

[angelodp]

Hi Phil, well I am baffled (little experience with T's - just the usual guitar stuff), here are the DC resistances all around.

Seems like two independent winds that are CT'd and not connected to each other, then a bunch of winds at low ohms, and a single wire not connected to anything. All 18g wire

Do you have an idea as to what I have here. Non of the dual leads are common to each other.

Is this a filament transformer for a big Organ amp?

[martin manning]

Put some low voltage AC on the winding with the lowest reactance and measure voltage on all including that one.

[angelodp]

Martin, so is my lowest resistance reading also my lowest reactance - I take it? I have a variac that is fused to feed in the Voltage (a few volts should do it). Would it be prudent to reduce the 6amp fuse in the variac down to 1 amp or even lower?

[maxkracht]

If you have a lightbulb limiter that should save you from toasting the transformer if you pick the wrong winding. A smaller fuse is probably safer, but I've personally never bothered. Start at 0vac and go up slowly, the bulb will glow if you messed up. I've hooked up a transformer the wrong way around a few times and turned the lightbulb on while testing...

[martin manning]

Sorry, spell check turned that into reactance. I was trying to write resistance. It doesn’t really matter too much which winding you choose if you are only putting a few volts on it.