Using an L/C section to match the output impedance of the H.G. valve to that LPF won't work, since that L/C section will interfere with the characteristics of the LPF. What you need is a cathode-follower between the HG valve anode and that LPF and, in turn, that LPF will need to see a 50 ohm load. And that, in turn, may require a grounded-grid stage to produce that impedance transformation (but not, obviously, if you will be using cathode-injection at the mixer. Just choose 50 ohms for the cathode bias resistor and design the rest of the cctry. for that valve around that value). Now both of those impedance-transforming sections should be obtainable with a double-triode, but very good screening between the two valve halves will be required.
In summary: you will only obtain the stated spec. of that LPF is it 'sees' a 50 ohm source and 'sees' a 50 ohm load. And its input must be well-screened from its output.
Al.
In summary: you will only obtain the stated spec. of that LPF is it 'sees' a 50 ohm source and 'sees' a 50 ohm load. And its input must be well-screened from its output.
Al.
