Thanks Scott for such a quick fix on this! While waiting on my K3 and I
was working on the softrock IF Kit, and I noticed the problem when I was
setting it up with the PowerSDR IF software.
I think I have found a supplier for a 32.800 Mhz crystal, which would
put the softrock at around 8200 and make it a more reasonable 15000hz
offset. I hope that this will still be far enough away from the 8215 IF
to not cause any problems, while making the bandpass a little more
symmetric.Someone else had mentioned the use of a HPL-4562 opto-coupler
to provide more buffering for the softrock. I may order one and give it
a try. If it works, a crystal even closer to the IF may work without
causing problems. Of course, I won't be able to test any of this until
my K3 arrives, hopefully in December as I am in the first batch.
Thanks again for your work on this, I know that many, including myself,
will enjoy using the features of PowerSDR with the K3,
73,
John KD8K
Scott McClements wrote:
On Nov 25, 2007 10:05 AM, John A. McCabe <[EMAIL PROTECTED]> wrote:
However, one possible problem
that I am seeing with the new version is that the IF frequency offset is
limited to a maximum of 20000 Hz and I believe that that Softrock for K3
requires a 23000 Hz Offset (8215 K3 IF frequency minus 8192 the softrock
frequency).
John,
I never noticed that the crystal that comes with Softrock for the K3
was so far off. The 20000Hz limit is just in the dialog validation
code, I just changed it to 96000Hz, and the DttSP code seems to have
no problem using a value more than 20000Hz. Thank you for pointing
that out. If someone needs this code right away I will build a special
patch - please only ask if you intend to use it very soon.
That crystal choice is not ideal, especially if someone can only use a
48Khz sampling rate. This means on the panadapter you will basically
only see 48Khz of band above the frequency you are tuned to. If you
are able to use a 96Khz sampling rate you will see 24Khz below and
73Khz above. I understand Tony, KB9YIG, only buys the readily
available crystal values to avoid the high cost of getting a custom
crystal frequency made.
-Scott, WU2X
http://www.wu2x.com/sdr.html
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