[Skimmertalk] Slow Scan

[Pete Smith]

At 04:38 PM 10/13/2008, you wrote:
>Is it possible for CW Skimmer to track a constantly shifting frequency,
>such as in conjunction with a CAT-interfaced rig having a 3 KHz
>bandwidth set to slowly scan across the band?  If so, would the
>resulting bandmap show the full spectrum between scan limits (whatever
>was received within the last ten minutes) or only a moving 3 KHz
>bandmap?  I've read Pete's very nice tutorial but couldn't tell if the
>bandmap width is restricted to the currently received passband.  I
>downloaded the trial program and played with it a bit last spring, but I
>didn't think to check this out before the trial period elapsed.
>
>Thanks es 73,
>Dave   AB7E

Hi Dave - the 3-KHz radio option assumes that your transceiver is in USB or 
LSB mode, or CW with a wide filter.  At any given time it is listening to 
the audio bandpass.  Each time that your radio is tuned (say, by a scan 
function), Skimmer takes a fairly long time by computer standards (like a 
second or two) before the decoders adjust and begin reading correctly 
again.  The best approach, in terms of covering w hole band this way, would 
be to use Skimmer's built-in controls (the up/down arrow button) to shift 
the base frequency 3 KHz at a time, and then wait long enough for it to 
decode whatever is in the next 3-KHz "bite".  A better approach is to use a 
separate stand-alone receiver, and I'm working on tutorials for two of 
those - the SoftRock and the SDR-IQ - that will allow decoding essentially 
an entire CW segment at a time.

73, Pete N4ZR