14-07-2025, 01:19 PM
My board is about populated and ready for transformers. No vintage radios were or have been destroyed in the process. In fact I quite like my old radio that picks up the local AM station that only ever seems to play oldie songs..perfect!!..
[email=https://hosting.photobucket.com/a9e03734-c956-4fae-9fe5-b64068513773/afbf782e-4b15-448e-b488-d51123870aa6.jpg]
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Here's my handy work so far.
![[Image: 7d157a4f-4f21-4d8f-8d9a-c1e845c49fe3.jpg]](https://hosting.photobucket.com/a9e03734-c956-4fae-9fe5-b64068513773/7d157a4f-4f21-4d8f-8d9a-c1e845c49fe3.jpg)
I have the input transformer worked out. DCR 200ohms : 100ohms CT. 50ohms each side of the CT. 2:1 wind ratio. With the size of my bobbin I'll go with 40AWG wire and just roll out 200ohms in length. Secondary ohms might be a little higher then 100ohms as Im rolling it over the top at a 2:1 ratio.
The primary transformer is still a bit of a mystery. If anyone has one of these old 7 pin transformers and can measure the DCR across / between all pins and check for continuity I'd be extremely greatful. Thanks for all the input to date.
[email=https://hosting.photobucket.com/a9e03734-c956-4fae-9fe5-b64068513773/afbf782e-4b15-448e-b488-d51123870aa6.jpg]
[/email]Here's my handy work so far.
![[Image: 7d157a4f-4f21-4d8f-8d9a-c1e845c49fe3.jpg]](https://hosting.photobucket.com/a9e03734-c956-4fae-9fe5-b64068513773/7d157a4f-4f21-4d8f-8d9a-c1e845c49fe3.jpg)
I have the input transformer worked out. DCR 200ohms : 100ohms CT. 50ohms each side of the CT. 2:1 wind ratio. With the size of my bobbin I'll go with 40AWG wire and just roll out 200ohms in length. Secondary ohms might be a little higher then 100ohms as Im rolling it over the top at a 2:1 ratio.
The primary transformer is still a bit of a mystery. If anyone has one of these old 7 pin transformers and can measure the DCR across / between all pins and check for continuity I'd be extremely greatful. Thanks for all the input to date.







