[Lowfer] Re: Amplifiers for 136k

[Johan Bodin]

Bill,

> 3. The output impedance of the stage, in spite of the filter, is close =
to 0=20
> ohms, and hence, makes a poor match for a coax line (take notice =
Mike).

That is no problem. In fact, the TX output impedance (resistance) should
be as close to zero as possible. Anything else means loss. A TX output
impedance of 50 ohms would result in 6 dB loss!

If the far end of the coax is terminated in 50 ohms (the antenna), the =
TX will
see exactly 50 ohms when "looking into" the cable (assuming 50 ohm =
coax).

However, "back terminated" cables are sometimes used in small signal
systems (video distribution for example) to avoid re-reflections if the =
load
end of the cable happens to be slightly mismatched. In the video case, =
this
would lead to blurred edges or "ghost pictures" depending on cable =
length.

73
Johan SM6LKM