[CQ-Contest] Skimmer ultimate setup?

[Pete Smith]

LP-PAN looks very nice, but I'd expect nothing less from N8LP - his stuff 
is great!  The big advantage of the SoftRock approach is the trivial pricetag.

There are two more options worth mentioning:

-- the SoftRock guys have just come out with a frequency-agile SoftRock 
Lite.  Another guy makes a 6-band bandpass filter board.  It would not be 
difficult to homebrew a 6-band receiver that could be tapped into the 
receive antenna loop on the second radio and switched by software (or 
manually).  The big advantage there is that neither Skimmer nor logging 
software would require any modifications.  In a single-band form, this is 
what is currently in use here for the Skimmer reverse beacon experiment.

-- RFSpace makes a little SDR called the SDR-IQ that will sample a swath of 
spectrum up to 190 KHz wide from 500 Hz (that's right, Hz) to 30 
MHz.  VE3NEA is developing Skimmer control of the SDR-IQ.  This could be 
used in the same way as the lash-up described above.  The only drawback is 
the cost, (~$500), but when not contesting it could be used for lots of 
other things, such as a spectrum analyzer or swl receiver.

73, Pete N4ZR

At 05:58 PM 3/20/2008, Joe Subich, W4TV wrote:

>Some additional comments ...
>
> > >3. The output of the Z10000 goes to a "Softrock Lite"
> > >receiver tuned for 8.215 Mhz. Maybe that frequency needs to
> > >be offset from the 8.215 IF to prevent the softrock Lite
> > >oscillator from getting into the K3 IF?
> >
> > You may not feel the need of the buffer amp (Clifton
> > Laboratories, K8ZOA, www.cliftonlaboratories.com) if you
> > offset the Softrock local oscillator so that it falls outside
> > the roofing filter bandwidth, but it would be a good
> > precaution.  On the radio to which my SoftRock is connected,
> > the local oscillator is S9+40.
>
>Keep your eye on the LP-Pan project by N8LP (www.telepostinc.com).
>LPPAN would replace the buffer/filter and softrock lite.
>
> > >6. CW Skimmer outputs spots to the logging program and puts
> > >them on the bandmap. I'm a little fuzzy on how CW Skimmer
> > >knows the frequency of these spots. Does it look at the rig
> > >control frequency of the S&P Radio, or is some other
> > >connection required for Skimmer to know the frequency?
> >
> > Ah, here's the rub -- Skimmer needs to know what frequency
> > your radio is tuned to, so that it can display the waterfall
> > with real frequencies rather than frequencies relative to the
> > Softrock local oscillator; that, in turn, means that Skimmer
> > needs to be communicating with your radio.
>
>N8LP's software suite will include a multi-port server that
>will allowed multiple programs (PowerSDR, CW SKimmer, logging
>program, etc.) to access the radio simultaneously.  Other
>testing indicates the important thing is that no program
>poll constantly at 100% of the radio interface capability.
>Icom radios will have significant issues with split status
>(as expected).
>
>73,
>
>    ... Joe, W4TV
>
>
>
> > -----Original Message-----
> > From: cq-contest-bounces at contesting.com
> > [mailto:cq-contest-bounces at contesting.com] On Behalf Of Pete Smith
> > Sent: Thursday, March 20, 2008 4:52 PM
> > To: Dave Hachadorian; cq-contest reflector
> > Subject: Re: [CQ-Contest] Skimmer ultimate setup?
> >
> >
> > Hi Dave - I think you are very close.  A few comments below.
> >
> > At 03:57 PM 3/20/2008, Dave Hachadorian wrote:
> > >I'm trying to figure out how CW Skimmer will ultimately
> > >physically tie in to an so2r contest setup. Let me propose a
> > >straw man, and then you smart guys can whip it into shape.
> > >
> > >1. We use the IF output of the so2r S&P receiver as the
> > >source of wideband RF.
> >
> > Yes
> >
> >
> > >2. Using an Elecraft K3 as an example, the IF output is at
> > >8.215 Mhz. I hear you need a buffer amp on that output.
> > >Somebody makes a "Z10000" that fills the bill.
> > >
> > >3. The output of the Z10000 goes to a "Softrock Lite"
> > >receiver tuned for 8.215 Mhz. Maybe that frequency needs to
> > >be offset from the 8.215 IF to prevent the softrock Lite
> > >oscillator from getting into the K3 IF?
> >
> > You may not feel the need of the buffer amp (Clifton
> > Laboratories, K8ZOA,
> > www.cliftonlaboratories.com) if you offset the Softrock local
> > oscillator so
> > that it falls outside the roofing filter bandwidth, but it
> > would be a good
> > precaution.  On the radio to which my SoftRock is connected,
> > the local
> > oscillator is S9+40.
> >
> >
> > >4. The stereo audio output of the Softrock Lite goes into a
> > >good quality soundcard with a high sampling rate, since we
> > >will be dealing with up to 50(?) KHz audio? This soundcard
> > >can be the one in the contest computer, since the soundcard
> > >is not normally used in CW contesting. If you want to do an
> > >audio recording of the entire contest, maybe you need
> > >another computer networked to the logging program and do the
> > >recording there?
> >
> > The soundcard I am currently using is a M-Audio Revolution
> > 5.1 PCU, which
> > cost me about $50.  It records 96 KHz stereo audio, which
> > translates into I
> > and Q channels that the Skimmer software will display as a
> > 96-khz swath of
> > IF bandwidth centered around the center frequency of your
> > SoftRock.  You
> > can get sound cards that go up to 192 KHz, for quite a bit more
> > money.  Look out, though, for cards that have shared mic and
> > line input.
> >
> > I use the audio CODEC in my MK2R+ to record contests.
> > Depending on the
> > BIOS in your computer, you may be able to run both a PCI
> > sound card and
> > your original on-board sound.  I can't, but that's Dell for you...
> >
> >
> > >5. Whichever computer gets the audio, it needs to be running
> > >the $70 version of CW Skimmer, and that computer also needs
> > >to be running the logging program.
> >
> > Yes, although the spots can be passed to the logging program
> > over a local
> > area network, so in theory you could have Skimmer on one PC
> > and the logger
> > on another.  It is worth mentioning here that the CPU demands of the
> > Skimmer, especially in contest circumstances are quite high;
> > this could be
> > disruptive to LPT or COM port CW, depending on your computer
> > and logging
> > software.  I run N1MM and Winkey CW, and experienced absolutely no
> > disruption with Skimmer running on a 2.2 GHz Celeron, even though CPU
> > utilization occasionally hit 100 percent.
> >
> >
> > >6. CW Skimmer outputs spots to the logging program and puts
> > >them on the bandmap. I'm a little fuzzy on how CW Skimmer
> > >knows the frequency of these spots. Does it look at the rig
> > >control frequency of the S&P Radio, or is some other
> > >connection required for Skimmer to know the frequency?
> >
> >
> > Ah, here's the rub -- Skimmer needs to know what frequency
> > your radio is
> > tuned to, so that it can display the waterfall with real
> > frequencies rather
> > than frequencies relative to the Softrock local oscillator;
> > that, in turn,
> > means that Skimmer needs to be communicating with your radio.
> >  The only
> > means Skimmer currently has for doing this is through
> > VE3NEA's OmniRig
> > interface, which works with many of his programs.
> >
> > Unfortunately, Omnirig is not compatible with the rig control
> > used by any
> > of the leading contest logging programs.  I have heard rumors
> > that Writelog
> > can be adapted to permit exchanging frequency data with
> > Skimmer - it may
> > well be that other logging programs can be readily modified
> > to supply radio
> > frequency data through UDP or other means, and that Skimmer
> > will evolve to
> > support such adaptations as they develop - but all of this
> > depends on the
> > software authors.
> >
> > I'd suggest reading the section of the Skimmer help file that
> > deals with
> > the "SoftRock with IF" option for further details.
> >
> >
> > >7. Since Skimmer will be connected to the S&P Radio, that
> > >radio pretty much has to be dedicated for S&P for the
> > >duration of the contest, otherwise Skimmer won't get much
> > >listening time because of all the cq-ing if it's connected
> > >to the run radio radio?
> >
> > Probably right, though I used Skimmer briefly during the
> > Russian DX contest
> > on my run radio - it would simply stop while I was CQing, and
> > then resume
> > copying calls as soon as I started to listen for callers.
> >
> > The way I visualize using Skimmer on Sunday in SS is that you
> > would switch
> > the S&P radio to a new band, pause a minute or so while
> > Skimmer works, and
> > then look on your S&P bandmap for Skimmer spots to call.  At
> > that point you
> > would just run up or down the band picking off any fresh
> > meat, and then go
> > on to another band and repeat the process.
> >
> > 73, Pete N4ZR
> >
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