UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - The Ever-Ready experimental transistor TV set.

FERNSEH · 5th Jul 2020, 10:32 am

"I suspect a tap may be included in the purple wire connection to chassis."
Hi David,
Absolutely correct, in fact the power supply circuit has been amended to incorporate a tap on the secondary winding. There would be no way the circuit would work without it.
Also, the polarity of the 6.2volt Zener diode was reversed.
It's safe to say that the 10uF slow start capacitor was added to protect the OC35 power supply transistor. Because high value smoothing capacitors are employed the in-rush current was destroying the transistor.

DFWB.

5th Jul 2020, 10:32 am	#72
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,444	Re: The Ever-Ready experimental transistor TV set. "I suspect a tap may be included in the purple wire connection to chassis." Hi David, Absolutely correct, in fact the power supply circuit has been amended to incorporate a tap on the secondary winding. There would be no way the circuit would work without it. Also, the polarity of the 6.2volt Zener diode was reversed. It's safe to say that the 10uF slow start capacitor was added to protect the OC35 power supply transistor. Because high value smoothing capacitors are employed the in-rush current was destroying the transistor. DFWB. Attached Thumbnails