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I wrote a PDF format report detailing my test results and
conclusions on the PowerSDR AGC issues. The AGC problems are
essentially identical for both PowerSDR- HPSDR and the current
versions for Flex Radio.<br>
<br>
Since attaching a PDF file to a list message is not allowed, I am
listing just the first three paragraphs of the report below. To
get a copy of the entire PDF file send an email request to <a
class="moz-txt-link-rfc2396E" href="mailto:gaddie@pacbell.net">"gaddie@pacbell.net"</a>
. The report is 5 pages and contains plots of the measured AGC
characteristics for HPSDR-PowerSDR W5WC, PowerSDR-Flex 1500 and for
comparison an Elecraft K3.<br>
<br>
First Three Paragraphs:<br>
<br>
<font color="#ff6666">"I recently installed Power SDR, W5WC Version
1.19.3.2, Date: 12-31-10. The setup is an HPSDR 3-board
combination of Ozzie, Mercury and Penelope. My computer uses an
Intel Core 2 Duo, 2.4GHz, 2GB RAM. The firmware versions are Ozy
1.7, Mercury 2.9, Penelope 1.2.<br>
<br>
In listening to on the air HF SSB signals I noticed some audio
distortion and non ideal AGC behavior compared to listening to the
same signals on an analog receiver. The AGC performance is better
than with the previous Power-SDR version but on my system it still
leaves a lot to be desired. In an effort to see what is happening
I ran some test on the Mercury board with stepped level and analog
variable level CW signals. I also did the same tests on a
Flex1500 and an Elecraft K3.<br>
<br>
The main conclusions are as follows. These apply to the latest
PowerSDR versions for both HPSDR and the Flex 1500. The AGC slope
option is not implemented properly. The Hang-Threshold control
does not work properly. If the Hang-Threshold setting is anything
greater than zero, for falling signals the hang and decay times
are not invoked. At Hang-Threshold settings greater than zero the
AGC provides no gain control on falling signals until the signal
is interrupted or it reaches a very low level. It behaves as if an
infinite hang-time were invoked. As there are interactions
between these various setting there may be other undiscovered
problems. The test methodology and results are described in
detail below."<br>
</font><br>
<br>
73,<br>
<br>
Pete W6XX<br>
<br>
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