[hpsdr] Munin2 Update

[Berndt Josef Wulf]

G'day,

FYI, I created a web page with the original mods applied and some graphs
showing the current vs temperature relationship as measured on my
module. This is work in progress...

http://www.ping.net.au/index.php?mode=munin2

My experience is that the NTC device doesn't closely match the
temperature drift of the final transistors. This is due to NTCs having a
non-linear temperature response, which makes it impossible to follow the
linear temperature characteristics of the final amplifier.

I also would like to make mentioning that temperature compensation for
the driver stage in the current design is ignored.

The last two graphs show gain vs frequency relationship and return loss
measured at the amplifier input port. These graphs show a resonance at
around 2.88MHz causing distortion of the amplified signal on 160m and
80m bands.

I would be interested to see measurements taken from other Munin
amplifiers to see if this is result is an isolated or systemic problem.

73, Berndt
VK5ABN

On Sun, 2014-03-09 at 12:45 -0700, Dick Faust wrote:
> ***** High Performance Software Defined Radio Discussion List *****
> 
> Kjell has supplied an revised circuit for the Bias that eliminates the pot.
> Details on my web page  http://www.k9ivb.net/munin2/  or link below for 
> basic info:
> http://www.k9ivb.net/munin2/New%20Bias%20Circuit%20For%20Munin2.pdf
> 
> I also added a link to Kingsoft Office a Free alternative to M$ office 
> that is cross platform on Windows, Android and Linux. Reads and writes 
> Office 97 to 2010 formats with selectable tool bars in Classic or Ribbon 
> format.  Also includes PDF output capability.  If you do not need all of 
> the M$ features like VBA etc. this is a very nice small FREE 
> alternative.  Win XP to 8.1 compatible.  Android version is uniquely 
> Android !  iOS is very limited.
> http://www.ksosoft.com/
> 
> 73, Dick K9IVB
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