Rich Measures wrote:
>>The 91B "absorbs" the input capacitance of the 4CX800As by making it act
>>as C2 in a pi-network. The tube input capacitance is about 100pF total,
>>and the fixed capacitors used for C1 are about the same value. Thus the
>>transceiver sees a 1:1 impedance transformation into the 50-ohm
>>At all HF/VHF frequencies, the grids see the 50-ohm resistor connected
>>directly to ground.
>If the grids are connected directly to ground, how it it possible to
>deliver grid bias potential to the grids?
The usual way, a DC blocking capacitor and RFC. Like I said, at all
HF/VHF frequencies, the grids see the 50-ohm resistor connected
directly to ground.
> . No neutralization? . Eimac recommends neutralization.
That's a sweeping over-simplification.
73 from Ian G3SEK Editor, 'The VHF/UHF DX Book'
'In Practice' columnist for RadCom (RSGB)
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