Old output transformer

[gary sanders]

If this thing is OK after I test it I will use it in my new 100watt I m building.It has a few extra secondary wires and was wondering if any of you may know what they are for.Has Black,Brown,Green,Yellow/Green but two more yellow with red places on them.

Also need to know if you can check the primary impedance of it just to make sure its ok to use.The guy I got it from had it in a push pull amp running two 6L6 with it but I dont want to kill it by running four of them.I dont know much about OT impedance and all that so if anyone could help Id love ya for it!And Im just big on using the old vintage parts and have heard that these old OTs sound really good.

[glasman]

Check this link out. It explains how to test transformer impedance. Requires a signal generator and DVM.

http://marstran.com/Measuring%20Primary%20Impedance.htm


FWIW, with a 440V supply and 4 x 6L6's you will need a primary plate to plate impedance in the range of 1800 to 2200 ohms.

Gary

[gary sanders]

what can i use for a signal generator?

[talbany]

Gary
Do a search on signal generator software programs some are freeware..Right out of the soundcard
here is one..

http://www.dr-jordan-design.de/signalgen.htm

Good Luck!!

Tony

[markusw]

what can i use for a signal generator?

You could use Visual analyzer software with your PC. It includes a signal generator. If you calibrate it with your DMM it should work.
http://www.sillanumsoft.org/download.htm


Argh, Tony was faster than me

Regards,

Markus

[talbany]

[gary sanders]

Hey thanks guys,Im on it!

[BobW]

The pic reminds me of an Ampeg portaflex PT.

[odourboy]

IIRC you want to determine the turns ratio between the primary and secondary, then square it to determine the impedance ratio. I did this once using a variac as my signal generator with the voltage kept low and compared the input voltage to the output voltage with a DVM to determine the turns ratio.

[gary sanders]

When I am reading the voltage on the secondary my DMM is flashing between zero and the reading,like going back and forth from AC to DC,is that normal?If so I have .028 on one tap and .014 on the other.

[odourboy]

When I am reading the voltage on the secondary my DMM is flashing between zero and the reading,like going back and forth from AC to DC,is that normal?If so I have .028 on one tap and .014 on the other.

That is not normal operation for my DVM. Mine flashes when you're measuring nothing i.e. an open circuit.