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

FERNSEH · 22nd May 2017, 10:07 pm

The 33Kohm screen feed resistor of the Z66 final vision IF amplifier valve was found to be open circuit, likely the result of a leaky 0.047mfd decoupling capacitor.
The signal generator has been connected to the mixer grid. It turns out the vision IF is 14.5Mc/s. So it follows the local oscillator operates below the carrier frequencies. Tomorrow, I'll turn my attention to the RF and frequency changer stages.

DFWB.

22nd May 2017, 10:07 pm	#59
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,444	Re: HMV 1804 Television. The 33Kohm screen feed resistor of the Z66 final vision IF amplifier valve was found to be open circuit, likely the result of a leaky 0.047mfd decoupling capacitor. The signal generator has been connected to the mixer grid. It turns out the vision IF is 14.5Mc/s. So it follows the local oscillator operates below the carrier frequencies. Tomorrow, I'll turn my attention to the RF and frequency changer stages. DFWB.