Posted Sun, 01 Jan 2023 10:28:10 GMT by Hord, Tavis
Hello,

I’ve got a vintage Tek 222 oscilloscope with a shorted transformer (T302) on the main board’s battery charging circuit and have found no way to source out a replacement.

Wondering if anyone has an idea of how I can find one or an alternative solution.

Part number for T302 is 120-1781-00 : Transformer Battery Charger 6 pin

schematic and board layout attached. 

Thanks for any info. 
 
Posted Thu, 05 Jan 2023 17:24:12 GMT by W2AEW, Alan Sr. Field Applications Engineer
This part is no longer available from Tektronix.  However, I have been able to determine that it is a 1:1 transformer with the primary inductance of 0.1mH, designed to operate at 40kHz.  Maybe this will help you to find a replacement, or re-wind the faulty unit.
Posted Thu, 05 Jan 2023 18:03:26 GMT by Hord, Tavis
Thank you my plan is to wind a new one.
I purchased a new Pot Core 18x11 + Bobbin (this one to be exact: https://www.ebay.com/itm/251637582555
as well as some 25AWG magnet wire: https://www.amazon.com/gp/product/B09L62169L/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&th=1

Do these look like they will work?

I am assuming i just wind the primary and secondary in parallel. Do you know how many turns it has?

Thanks again,

-Tavis

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