[NLRS] Amp suggestions

[John P. Toscano]

hill195@mchsi.com wrote:
> 
> I agree with Jerry 100%. The first thing I do with a
> brick is rip out or somehow disable the COR circuitry
> inside. It is, IMHO, the only way to have reliable and
> predictable PTT operation. If you want an effective
> preamp for weak signal work, the second thing you
> disable is the preamp inside a brick. Preamps, IMHO,
> belong up top.

Okay, John (K0PW), I basically agree with your advice to John
(KC0LBT), but. . .

1) Some bricks have a PTT input on them already, so you don't need
to rip anything out (like my RF Concepts bricks, however the company
was bought out and liquidated, so you won't find them for sale new
any longer).  Mine can use either +12v or ground to initiate PTT
action, and they have COR available if a PTT signal is omitted.
And if you are running a transverter, you naturally need a PTT
signal into the transverter, and tapping that for the brick is
quick and easy if the brick has (or can be modified for) a PTT input.

2) In a rover station, the distance between the radio and the
antenna tends to be small enough that putting the preamp "down below"
instead of at the antenna is not such a big travesty.  The other
issue, however, is that you can get a much better separate preamp
than what is usually found inside of a brick, so an antenna-mounted
or mast-mounted preamp is still not a bad idea for maximum perfomance.
Of course, that means T/R switching at the preamp, either as a built-
in feature (only some have this, and may impose a low limit on your
transmitter power), or as extra relay circuitry that you add.

73 de John (W0JT)
(Johns, Johns everywhere, except when you really need one)  :)