[hpsdr] munin pa update

[Bob G Mahrenholz]

Hi Georg,

Thanks for the info. I had missed that. Can you go into a little more
detail on just how you grounded the center tap of L5? There is a pad
there for that purpose but it does not seem to be grounded. From the
picture it looks like you used a copper strip to ground the pad but
how did you ground the strip. Did you scrape the green mask off the
copper ground plane at that point and solder the pad to the copper
strip?

Thanks for sharing this info with us.

73,
Bob, K4QQK


-----Original Message-----
>From: Georg Prinz <getpri at t-online.de>
>Sent: Sep 7, 2012 4:17 AM
>To: hpsdr at lists.openhpsdr.org
>Subject: [hpsdr] munin pa update
>
>***** High Performance Software Defined Radio Discussion List *****
>
>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
>
>
>
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