[Moon-net] Linrad and SDR-IQ for weak CW

[LANCE COLLISTER]

Hello!

I am slowly trying to get LINRAD set up here so I can use it to copy very weak 
stations on 6 EME who do not have the capability to run JT65a mode.  I would like 
to get this working by early June, if possible.  I got a second computer last 
summer with the intent of using it with my SDR-IQ, LINRAD and possibly other 
programs that can captitalize on the wide bandwidth of the SDR-IQ receiver.

I do finally have my second computer working (after sending the MOBO back twice), 
and it really seems to fly with the dual AMD 64 processor :-)  I have installed 
Vista 64 on one hard disk and 32 bit Windows XP on the other, and I have pretty 
much resigned myself to just using the Windows XP O/S for the time being because I 
can get it to work with various drivers.  I also finally now have an M-Audio Delta 
44 sound card in it, with the idea of being able to have 96 kHz of bandwidth one 
way or another.  I realize the SDR-IQ has twice that bandwidth, but I understand 
that Linrad is limited to 96 kHz.

I have heard that LINRAD can work very well for copying weak CW, but also that my 
"filters need to be calibrated" - whatever that means.  Has anyone with more 
technical savvy and equipment than me who is using an SDR-IQ for input been able 
to "calibrate their filters"?  Is there some setup file or something that you 
could share with me?

By the way, I have been using this new faster computer with the Delta 44 sound 
card as a backup to monitor JT65A skeds on 6m EME, and I have been very pleasantly 
surprised by the results!  I had been very pleased with the performance of my 
Turtle Beach Santa Cruz sound card on my primary computer (a single AMD 64 
processor).  However I now find that the dual processor computer with the Delta 44 
sound card almost always decodes the JT65A signals 1 dB stronger than my main 
computer....and often it will produce a full decode showing the callsigns even 
when my main computer only shows a "*" or *#" and no decode of the signal trace. 
Of course, I entered the corrections factors for each sound card into the version 
of WSJT running on each computer. So, although my original goal for getting the 
Delta 44 was to be able to have more options with LINRAD, it is turning out to be 
very effective for narrow band JT65A also.

I would appreciate any suggestions anybody might be able to provide regarding the 
SDR-IQ and filter calbration and/or LINRAD setup files for use on weak CW.  MNI 
TNX and VY 73, Lance


-- 
Lance Collister, W7GJ (ex: WN3GPL, WA3GPL, WA1JXN, WA1JXN/C6A, ZF2OC/ZF8)
P.O. Box 73
Frenchtown, MT  59834  USA
QTH: DN27UB
TEL: (406) 626-5728   URL: http://www.bigskyspaces.com/w7gj
2m DXCC #11, 6m DXCC #815