Koyo KTR-1375L-AC

[Danndad]

Can anybody please assist in finding a schematic for the Koyo KTR-1375L-AC?

Danndad

[Mike Watterson]

There may be schematics for the Ross and Grundig versions of it. The Ross badged version:
FM/AM/SW Twin Speaker RE-1915-N
https://www.radiomuseum.org/r/ross_re_1915_n.html

I couldn't find a matching Grundig. Only a few were "Koyo".

The Koyo
https://www.radiomuseum.org/r/koyo_denki...5e_ac.html

AFAIK 403 isn't a model, but the MITI OEM code for who really makes badged sets. Sets from the OEM with their own brand lable often omit the MITI code.

Most of the Koyo have no schematics.

What's wrong with it?

[Danndad]

Thanks for taking the time to look Mike.
The radio was drawing high current initially but that was due to the mains isolator switch not functioning correctly, once that was sorted the radio was very quiet.
There were orange plastic cased NTK electrolytics in this which always give trouble, especially the low value ones, these were replaced and radio was working lovely.
I decided to replace the last 2 larger value power supply electrolytics whilst it was all out of the case but after those 2 were done I now have very high current at switch on.
Thankfully a friend emailed a link to RM that has a koyo that is very similar to mine.
Danndad

[Danndad]

Here is the link to the one I can use, only difference is the mains supply voltage and this has sw whereas mine has lw.

https://www.radiomuseum.org/r/ross_fmams...istor.html

[Mike Watterson]

Great. Very similar to the Ross I found, but with a circuit.