[Amps] filament choke

[Peter Chadwick]

The filament chokes I use in my grid driven amplifier for applying NFB are wound on ferrite toroids, about 2 inches in diameter and 3/8 inch wide and thick. But they have lower inductance, as they only need to be about 10 microhenries at the most, and are shunted RF wise by 10 ohms. For a grounded grid approach, of course somewhat more inductance is needed, especially on 160....The rod approach has the advantages Tom outlines then.

73
Peter G3RZP