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

FERNSEH · 11th Oct 2019, 12:38 am

Hi David
Does the RB7 employ tuning capacitors or like the RB12 variable inductances to do the tuning? The RB12 covers 300 to 3000 metres in four switched ranges.
I been searching for more than thirty years for the construction information of the coil assemblies in the RB12.
The DEV was designed to keep the anode to grid capacitance as low as possible. I believe the valves operate on only 40 volts.
In the RB12 a DER triode functions as the RF amplifier and reflex audio amplifier. HT is 40 volts.
Information about the DEV: https://www.radiomuseum.org/tubes/tube_dev.html
The DEQ: https://www.radiomuseum.org/tubes/tube_deq.html
The V24: https://www.radiomuseum.org/tubes/tube_v24.html

DFWB.

11th Oct 2019, 12:38 am	#5
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,444	Re: Marconi R.B.7. Hi David Does the RB7 employ tuning capacitors or like the RB12 variable inductances to do the tuning? The RB12 covers 300 to 3000 metres in four switched ranges. I been searching for more than thirty years for the construction information of the coil assemblies in the RB12. The DEV was designed to keep the anode to grid capacitance as low as possible. I believe the valves operate on only 40 volts. In the RB12 a DER triode functions as the RF amplifier and reflex audio amplifier. HT is 40 volts. Information about the DEV: https://www.radiomuseum.org/tubes/tube_dev.html The DEQ: https://www.radiomuseum.org/tubes/tube_deq.html The V24: https://www.radiomuseum.org/tubes/tube_v24.html DFWB.