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

FRANK.C · 21st May 2010, 9:31 am

Hi Mike
The D cell is a great idea.

You previous post has given me food for thought. Thanks for that information especially on how the AVO's get around that problem.

As I have already got a heater transformer wound I will have a play with making a filter to remove the 50 Hz. I would think that the rejection would need to be considerable as the grid signal is much smaller that the AC across the heater. I may well try filter + balancing resistors across the heater.

Chances are that I will fail miserably but it is all good fun.

Frank

21st May 2010, 9:31 am	#376
FRANK.C Heptode Join Date: Feb 2006 Location: Roscommon, Ireland Posts: 732	Re: The "Sussex" Homebrew Valve Tester. Hi Mike The D cell is a great idea. You previous post has given me food for thought. Thanks for that information especially on how the AVO's get around that problem. As I have already got a heater transformer wound I will have a play with making a filter to remove the 50 Hz. I would think that the rejection would need to be considerable as the grid signal is much smaller that the AC across the heater. I may well try filter + balancing resistors across the heater. Chances are that I will fail miserably but it is all good fun. Frank