[hpsdr] munin pa update

[Georg Prinz]

Hello,

actually I put two munin power amplifiers successfully into operation.

To those who are in a similar situation following hints:

My information is based on  two boards dated 04.03.2010 and drawing
dated 19.04.2012.

1. The center pad of L5 shall be grounded. See Picture munin_L5 on
www.qsl.net/dl2kp

Drawing shall be updated accordingly.

2. Picture munin_L4 on www.qsl.net/dl2kp shows L4 how it shall be done.
Both ends of the secondary coil shall be facing towards T1 and T2. One
end shall be longer to reach to the soldering pad for output behind the
jack.The other end I soldered to nearby ground point.
Furthermore, you see the correct mounting of T1 and T2. I put a copper
bar beneath the MOSFETs not only for heat distribution, but also to be
able to place drain and source connection without bending them on top of
the board.

3.The idling currents should be adjusted to get full power on all bands.
  Kjell recommends for T3/4 500mA each and 1 A for T1/2 each. I am just
experimenting around to get the correct value for my boards.At the
beginning I didn't succeed with kjell's values to get full power.

4. I was curious, if the output sma connector would be sufficient for
100W and even more.According to the data sheet it has a working voltage
of 355V. With 200W you will get a voltage of 70V at 50 ohms.So that
should be ok.


At the end I will not forget to thank Kjell for his great development
and all the help he gave me to get everything into operation!

Vy73,

Georg, dl2kp