[Amps] Question about Marconi amp filter board

[Michael Tope]

----- Original Message -----
From: "Web Williams" <kr4wm at earthlink.net>

>
> My question is this- in the group's opinion, would the RF
> follow the path of least resistance if I just tie all the filter
> inputs and outputs together (sort of like installing multiple
> Hustler loading coils on a mobile antenna), or must the
> various filter combinations be switched in and out as band
> changes occur? I guess I -could- run it without the filter
> board, but it probably would no longer meet spectral purity
> requirements, which is why the engineer put the filter
> board there to start with. I want to use it if I can.

Assuming these are low-pass filters Webb, then tying them
together in parallel will not work. At the lower frequencies,
the high-band LPFs will bypass the  rejection of the low-band
LPFs thereby rendering them useless (poor harmonic rejection).
At higher frequencies, it might work if the low-band filters use
series inductors at their inputs and outputs. If they use shunt
C at either their input or output terminals, then they will short
the high-band signal to ground (not good).

73 de Mike, W4EF....................................