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Old 20th Mar 2019, 1:38 pm   #65
BillDWVA
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Join Date: Nov 2010
Location: Tenby, Pembrokeshire, Wales, UK.
Posts: 139
Default Re: Ferrograph 4A: Restoration advice needed

Quote:
Originally Posted by Uncle Bulgaria View Post
I'm in the process of adding the modification written up by 'Pichacker' in another thread from a few years ago, when he was fixing up a Vortexion. It's an RC filter on V3's grid, to block DC and give a constant grid-leak rather than the current arrangement where the volume control is the grid-leak. That will be done tomorrow when I get some more yellow capacitors.
I’ve done this ‘mod’ to a couple of Vortexions too, and can report that it is worthwhile. The volume control is quieter in operation with the DC blocked.

Bill
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