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

ms660 · 29th Jul 2018, 12:10 am

Same difference as it were, the grid is at HT -ve (chassis) potential which is -ve with respect to the cathode, all cathode bias circuits work that way eg: there must be an external DC path between the grid and cathode. Some other methods of obtaining the bias voltage include a battery or a -ve supply from within the receiver by using the voltage developed across a resistor in the HT -ve rail as the source or by grid leak.

Lawrence.

29th Jul 2018, 12:10 am	#17
ms660 Dekatron Join Date: Apr 2011 Location: Cornwall, UK. Posts: 13,454	Re: Bestone TRF - power up and audio stage testing Same difference as it were, the grid is at HT -ve (chassis) potential which is -ve with respect to the cathode, all cathode bias circuits work that way eg: there must be an external DC path between the grid and cathode. Some other methods of obtaining the bias voltage include a battery or a -ve supply from within the receiver by using the voltage developed across a resistor in the HT -ve rail as the source or by grid leak. Lawrence. Last edited by ms660; 29th Jul 2018 at 12:29 am. Reason: clarification