I.D.ing a power transformer

[dubiousss]

I remember once reading a great article about a guy who found transformers in a junk yard and turned them into tube amps, and the page explained how to find the impedance of the power transformer, without an oscilloscope. Anyone know this article?
I ask because I have an old unmarked transformer that was used in an 8 tube stereo music amp, that I now want to build a tube amp out of. I dont have an oscilloscope. But I do have this transformer, some el34s,6v6s,21ax7's,sockets a speaker and some guy telling me he'll pay for a tube amp.
I just need a way of finding out what this is transformers capable of so I can match it to a schematic and away I go...

 

[jim p]

here is a web page to give you some ideas

Here is one article I found searching about http://www.radioremembered.org/xfmr.htm
Using a light bulb in series when you first connect it to line voltage would be a good idea. If you want to start off testing with lower voltages connect low voltage AC to the primary input say 12 VAC and figure the outputs will be a factor of 10 greater when connected to line voltage. You will need some watt wasting power resistors to check the load capacity.

 

[dubiousss]

ok so,
on one side theres two black,(.7ohm) and 4 wires (white, yellow, brown) that all connect (ground?)
on the other side there theres 2 red (35ohm), 2 blue (7ohm), a green -orange - brown set that has a 8 - 12 - 20ohm reading so orange would be center tap.
theres also a yellow/white thats been soldered togeather and connects to the 4 unknowns on the other side (ground?)

I pulled apart a 12V DC adapter to get at the lower voltage AC and connected that (it read 8V AC)
the red read 380V
blue 226V
green-brown 112V
brown-orange 45V
green-orange 66V

im in NZ so im on 230VAC

so i imagine with the full 230V it will have huge voltages, there were two other transformers that came with this one so i guess they where used for the 6.3V's

 

[jim p]

check to see how the primaires are wired

That is awful high voltages you have I attached a picture of the two common ways that transformer primaries are set up on transformers. Maybe you connected across a boost winding 100 VAC to 120 VAC that would make for a high step up ratio.