> Date: Sun, 29 Dec 2013 18:59:40 +0100
> From:
[email protected]
> To:
[email protected]
> Subject: LF: MF PA
>
> Hi Wolf,
>
> What type of FETs are you using? The standard IRFPs? Many of them
have
> internal Z diodes, so no addional RC network or Z idode is needed.
The
> losses are there anyway, of course.
>
> In some older projects i also played with that critical working
point,
> i.e. where one FET shuts down and the other opens. I've tried
simple RC
> networks (series R, parallel C) with an 100 Ohm trimmer. That
worked
> reasonably but usually it is not even necessary. My small MF PA is
using
> a simple ICL7667 and 2x IRFZ48N (Reichelt...) without problems.
> My large PA generates up to 1.2 kW, which is also enough to reach
1 W
> ERP,
https://dl.dropboxusercontent.com/u/19882028/MF/mod%20MF%20PA.jpg.
> It was designed for field experiments (Field day) where MUCH more
> inefficient antennas will be tested, e.g. in France, next year, if
they
> have the allocation then...
>
> 73, GL, Stefan/DK7FC
