impedance matching Transformers for audio

Yours requires a different transformer
@175 ohms

 

Maximum efficiency only occurs when you eliminate the mismatch.
Assuming fidelidy as well

 

I have no tool for measuring inductance.
I need a 9 volt battery for my meter so I can't measure dc resistance at the moment, but the Telex part# is 04369 and since Telex sold Turner, they divested their supplies of those parts and the new Chinese manufacturer refuses to sell spare parts. The object is to raise the 150 ohm impedance to 600 ohms to increase the audio output level of the microphone. I have plenty of mics wired for my personal use, but I have 25 more to wire for posterity with no ideal transformer available. The transformer makes a drastic difference in output level. If you get a chance look inside a Turner RK56 and you will see the part I am referring to.
In regards to the preamp, this is for mobile use. I like to keep things simple.

 

If someone could reverse engineer that transformer, I would pay a pretty penny for someone to write a tutorial on how to hand wind a replica.

 

This is the exact transformer. No longer in production. Black and brown wire connect directly to the microphone element which was 150 ohms to begin with, and the red and yellow wire connect to shield and audio with a .1uf capacitor in line with the audio wire to narrow frequency response. With the brown and black wire connected to the microphone element if you measure DC resistance through the red and yellow wire you will see 600 ohms but if you disconnect the brown and black wire from the element the DC resistance measured across the yellow and red wire is much less.

 

I think I probably will buy one of these things so I can measure the inductance of the primary and secondary windings before I disassemble one to count the number of turns

http://www.ebay.com/itm/like/331743...7290-0%26rvr_id%3D1014618849403&ul_noapp=true