UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post

unitelex · 30th Jul 2020, 2:17 pm

Assume you have checked the power rails are reasonable, the 1st stage gets regulated supply via 18V Zener so that should be circa 18V and the rectified secondary should be 20 something volts or so.

Worth comparing performance between the two inputs, if no appreciable difference then the problem would seem to be around Q3 Q4 stages.

Also check the bias oscillator (2x BFY51) is reasonable amplitude and frequency

Best Regards
Chris

30th Jul 2020, 2:17 pm	#5
unitelex Hexode Join Date: May 2005 Location: Greater Manchester, UK. Posts: 496	Re: Wem Copicat Mk4 repair Assume you have checked the power rails are reasonable, the 1st stage gets regulated supply via 18V Zener so that should be circa 18V and the rectified secondary should be 20 something volts or so. Worth comparing performance between the two inputs, if no appreciable difference then the problem would seem to be around Q3 Q4 stages. Also check the bias oscillator (2x BFY51) is reasonable amplitude and frequency Best Regards Chris