Wednesday, August 21, 2013

Using the Funcube Dongle Pro+ with CW Skimmer

by Gabriel Sampol, EA6VQ

reproduced with permission of the author from

http://www.dxmaps.com/funcube.html  

Editor's note: The Funcube Dongle Pro + is a tiny and relatively inexpensive receiver that plugs into a USB port and is capable of 192-KHz coverage between 150 KHz and 1.9 GHz.  Because it does not blank out US cellular telephone frequencies, the DP+ is not legal for use in the United States.  For interested readers elsewhere, you can read more at the maker's website.

 

I got a Funcube Dongle PRO+ with the idea of setting up a secondary Reverse Beacon receiver for 28 and 70 MHz bands.  To my disappointment the current version of CW Skimmer (1.8) does not support this device so I have spent some time investigating how to make it work.

First of all I noticed that CW skimmer was recognizing it and it was receiving if I configured it as a Softrock with a 192 kHz Sampling Rate.







However, the frequency received had nothing to do with the value of  "LO Frequency, Hz". There was an offset all over the band.

I then realized that the shown frequency had to do with the last frequency set in the Funcube by another SDR program (SDRsharp) that I had used just before, so it was a matter of setting the right frequency with a program that supports the Funcube and setting that same frequency in CW Skimmer.
With this simple two-step procedure you can satisfactory use the Funcube Dongle PRO+ with CW Skimmer, and of course also use it for the Revese Beacon Network thru Aggregator.

This is an example on how to set the LO frequency to 28095 kHz, to cover the lower portion of the 10m band.

1. Download the FCHID (FCD+ Frequency Control Program) program for Funcube, place it in the CW Skimmer folder (for instance) and run it.  Set the frequency to 28095.




2. Set the LO Frequency to 28095 also in CW Skimmer, as shown in the first image.
And that's it.  You will be receiving the 27999 to 28191 kHz band and the frequencies shown in Skimmer will be correct.
No need to say that if you want to receive another band you will have to repeat both steps.



Well, now that I had it working I wanted to go one step further and find a way to switch bands automatically, so that I could monitor several bands sequentially. In order to it I obviously had to find a way to programmatically change the frequency in both, FCHID and CW Skimmer.

In order to change it in FCHID I developed a small program that uses Windows API calls. I called it ControlFCD and it accepts a frequency in kHz as a command line parameter (For instance "ControlFCD 28123" will change the Funcube frequency to 28123 kHz in FCHID).  No need to say that FCHID must be running when executing ControlFCD.

For changing the LO Frequency in Skimmer I didn't find a better way than changing this value in the CWSkimmer.ini and restarting the program so that i takes the new configuration file.  Instead of modifying the ini file I opted by creating different copies of the original file, each of which with the desired value of frequency, and copying then later over the CWSKimmer.ini.

Finally, I made a simple VBS to control the whole process of starting all the programs and automatically managing band changes at certain times. You can download this VBS as a sample and the ControlFCD program for your convenience.

Important: Download and use these programs at your own risk. They work fine for me on Windows XP, but you may need to modify the VBS for your own use and you will need some basic programming skills for this purpose. They are also likely not to work in later version of Windows, without changes. I can't provide you support about them.


Saturday, August 17, 2013

Testing Spot Quality Filters

It's been a busy and rewarding couple of weeks.  Sometimes, I'm quite overwhelmed by the willingness of hams to invest large amounts of time and intelligence in advancing our hobby, not for any personal gain but simply because they care and enjoy what they are doing. 

This is one such case.  The AR Cluster V6 Telnet server at the RBN has just been replaced with a beta version that provides quality scores for each RBN spot, as well as filters enabling users to apply those scores to limiting the spots they receive.  Note that if you don't set any of the new filters, the node will continue to function as it always has, except for the addition of a validity code as part of the comment on each RBN spot.  All existing filters will continue to work as before.  The full story is at <http://www.ab5k.net/ArcDocsVer6/UserManual/ArcDx_CT1BOH.htm>.

Special thanks to CT1BOH, who did extensive analysis of RBN data and developed the innovative algorithms being used, and to AB5K, for the hard work of coding and testing the filters for incorporation in this new version of his cluster software.


During the beta period, users will see a set of new tags in the comment field of spots coming from the RBN ARC6 Telnet server.  These will not be a feature of the finished version, so software that relies on a particular format in the Comment field of spots will not have to be modified.  Users will see the quality tag, but in order to filter using them, the node they are connected to must be running the beta server software as well.  Users can test with the RBN node at arcluster.reversebeacon.net, port 7000.  Node sysops who want to try the beta are encouraged to contact AB5K.

These are the quality tags:

? - Not yet verified.  The first and/or second identical spot of the same station, including erroneous spots of callers 
V - Valid, meaning that at least three identical spots (call and frequency) have been posted by Skimmers worldwide
Q - QSY?, meaning
that it is the first and/or second spot of a station on a new frequency, where spots of that station were previously verified. Sometimes, this will be a legitimate QSY, but the tag may also indicate an I/Q image of a good spot.
B - Bust, based on whether a new spot is enough like ones already seen and tagged Valid, except for a difference in the callsign.  This is based on a really clever applied math concept called the Levenshtein distance.  Google for more info.
. - Unique, meaning that there are only one or two stations currently spotting stations in a given country.  Will often change to V if more stations spot it, but in the meantime you won't miss that P5 because only one RBN station heard it.

You can filter so that you get only Valid spots, or so that you can block all busted spots, or so that you get no Q spots until they are verified (so I/Q images will not come through).  You can even tell the cluster node to let through spots with a "." tag, so you don't miss the really rare one who is only spotted by one or two stations.  Full info and examples at the URL above.

I do not assume that this is the last word on improving RBN spot quality.  Beta means beta.  Please experiment, see what you think, and let me know.  One particularly fruitful line of inquiry would be to compare the arrival time of unfiltered spots and spots that have been judged Valid, to note instances when an apparently legitimate spot doesn't get through or is judged to be a bust, or when a bust is not caught. 

In this connection, in testing we have noticed that sometimes a Busted call will be mistakenly judged Valid, because there are more busts than good spots in a time window.  Often, this seems to be due to spacing errors (RN4ZR for N4ZR), frequent omission of portable designators by ops (N4ZR instead of P5/N4ZR), and PTT cutting off the first dit (E4ZR for N4ZR)  

Please send your comments/reports to me, and I'll see to their onward distribution.  Do not send them to this reflector!



73, Pete N4ZR

Monday, June 24, 2013

6 Meters and the Power of the Reverse Beacon Network



by Paul Carreiro, N6EV
The Reverse Beacon Network has evolved to become a powerful tool with quite a few Amateur Radio applications, mostly on the HF bands.  Antenna comparisons; spotting contest and DX stations; checking to see where your transmission is being heard; and seeing which bands might be open to particular parts of the world at any given time are just a few examples of the RBN’s usefulness.  The RBN also provides a very unique opportunity for real time propagation awareness on VHF, and in particular on 6 meters.
“The Magic Band”
6 meters is known as the ‘Magic Band’.  It got this nickname in part because of the wide range and transitory nature of its propagation modes. F2, Sporadic-E, Transequatorial, Tropospheric, Back Scatter, and Meteor Scatter are all propagation modes regularly observed on the band, often at the same time or in combination!  The power of RBN’s ever-listening ear, combined with the existing constellation of active beacon stations, enables an awareness of 6 meter band conditions unheard of before now.    
In the case of sporadic-E, the added path information helps more than just those operators geographically close to the RBN node and spotted station.  The center of a sporadic-E path is generally where the ‘E Cloud’ resides.  As a result, operators around the spotted path are alerted to probable centers of sporadic-E ‘cloud' activity.  This allows them to anticipate additional paths that share the common 'cloud' center; or even connect multiple ‘cloud’ centers into multi-hop paths.
RBN and 6 Meters in Action
Here are a couple of excellent examples of 6 meter propagation as shown on the 6 meter maps at dxmaps.com.  Often, RBN spots (green callsign paths on the map), particularly of beacons, are some of the first to show up, indicating the start of a sporadic-E opening.



Note how the intersection of the paths clearly locates the sporadic-E cloud area.  Dxmaps.com also offers a real time EMUF map view showing the upper cutoff frequencies for each sporadic-E center of activity.
Of course, it works in Europe too.

The Reverse Beacon Network coupled with DXMaps.com equals fantastic real time 6 meter propagation awareness!

Unique Issues for 6 Meter RBN Nodes
You’ll note in the maps above that some of the spots in both Europe and the U.S. were derived from active beacons.  In order to spot beacon stations on the band, Skimmer must be configured to pass all callsigns, not just CQing stations.  However, disabling this filter opens up the possibility of Skimmer falsely spotting a callsign it decodes from digital spurs created by consumer electronics that seem to be prevalent on 6 meters.  The callsigns of these false spots often contain lots of dits (e.g. EI5I, ES5I, EE5E).  
 A situation can also arise where Skimmer decodes not only the callsign of the station being heard, but also of the unheard station being worked.  This is the result of the heard station sending the unheard station’s callsign repeatedly in an exchange.  This is common on HF too, but would be considered a particularly unhelpful false spot on 6 meters as the propagation path between the RBN node and the unheard station does not exist.

The steps to help eliminate false spots for a 6 meter RBN node are relatively simple.
1.    Turn ON Skimmer’s Aggressive Call Validation – this forces Skimmer to decode the callsign more times in a row before it is announced.  It also puts a higher weighting to callsigns in the Watch List (see next item)

2.    Populate the Skimmer Watch List with a list of callsigns of known beacons and other stations heard on the band operating CW.  With aggressive call validation active, any call in the Watch List will be validated more quickly.  A good source for this is the current World Wide 6 Meter Beacon List maintained by G3USF, stripped of all the text except the callsigns.  In addition to beacon calls, you can add the calls of CW ops worked or spotted from your location.  This way subsequent spots are validated quicker.  The Watch List can be managed easily as an external text file with a text editor.  Include comment text to help organize the list into sections.  Cut and paste into Skimmer when updated.

3.    In Aggregator, under the Spot Filters tab:

     a.    Enable the filter to eliminate callsigns that look like grid squares.  Many beacons send grid squares identifiers which are occasionally misinterpreted by Skimmer as callsigns.

     b.    Enable the filter to not send VHF+ callsigns with 1dB SNR or less.  Many of the digital spurs on the band are close to the noise floor.   Typical false spots with lots of dits show up with 1dB SNR
.
     c.    If you have known digital spurs that repeatedly are the source of falls spots you can populate those frequencies in the bad frequency list and click the appropriate filter to not spot those frequencies.

     d.    If you have persistent false spots from partial callsigns, or incorrect beacon call signs (usually from poor automatic beacon CW spacing), you can add those bad callsigns to the bad callsign list and click the appropriate filter to eliminate them.

4.    Monitor the 6 meter spots from your RBN node on a regular basis.  Look for false spots and analyze if any adjustment in filtering is necessary.  You can also collect additional spotted callsigns to include in your Watch List.

5.    Update the beacon callsigns in your Watch List to represent exactly what is spotted and/or sent over the air.  Many beacons send a call suffix of /B not represented in the G3USF list.

6.    Keep your Skimmer and Aggregator software up to date.   Features, filters and algorithms are improved and added from time to time.

Performing these few steps will eliminate most of the false spots typically reported by new RBN nodes on 6 meters.

6 Meters Needs Your Help!
We need additional 6 meter RBN nodes in North America!  Europe currently has much better RBN node coverage on the band and as a result enjoys very good early warning of 6 meter openings.  At the moment a handful of full time and part time nodes are in operation in the continental U.S.  We could really use additional coverage in the Mid-west, Gulf, Plains and Western states (is that all?!).  The more diverse and plentiful the nodes are the better.  It’s summer time.  And that means sporadic-E season is upon us.  Activity on 6 meters is hot.  So now is the time to set up a 6 meter RBN node!  If you have a QS1R coupled with Skimmer Server, consider giving up one of the lower frequency bands in favor of 6 meters from mid-May through August (sporadic-E season) each year.  Softrock offers a single band VHF SDR kit at a reasonable price, making it a good choice for a full time 6 meter RBN node.

6 Meters for the Uninitiated
For those not familiar with the 6 meter band layout, CW activity can be found between 50.000 and 50.126 MHz.  International beacons are found between 50.000 and 50.060.  The U.S. beacon band runs from 50.060 to 50.080.  Point-to-point CW QSOs are found between 50.080 and 50.100.  The DX window, which includes CW activity, runs between 50.100 and 50.125.  50.125 is the U.S. SSB calling frequency.  Some CW ops often call CQ on the SSB calling frequency (an accepted practice) to drum up activity when there aren't many signals on the band.  

In Skimmer, configure the 6 meter CW band limits between 50.000 and 50.127 without any beacon band annotation.  Depending on available bandwidth, your 6 meter RBN should concentrate on 50.059 to 50.127 (in the U.S.), and if you have the available bandwidth, run Skimmer between 50.000 and 50.127. Note: Even if you can run 192-KHz bandwidth, the default Skimsrv.ini file has the 6m CWSegment set to 50.0-50.1 MHz.  You'll need to edit that line to 50000000-50130000 before Skimmer Server will decode above 50.1 MHz.

Antennas for a 6 meter RBN node don’t need to be elaborate.  Even though the vast majority of weak signal work (CW/SSB) on 6 meters is done with horizontal polarization, a vertical works well for skimming and has the advantage of the omnidirectional pattern.  I’ve used a simple Cushcraft Ringo Ranger for my 6 meter RBN node the past three years with great success.  A halo for omnidirectional horizontal polarization is commercially available and is also easy to build.  If you don’t have a 6 meter-specific antenna, the use of a preamp is advisable.

Contact me, the RBN team or Mark, N2QT, who also operates a full time 6 meter node, if you need help setting one up.

73 – Paul,  N6EV

Sunday, June 23, 2013

A Low-Cost Specialized Skimmer Computer

I thought others might be interested in the specs and design criteria of my new Skimmer computer. 

First, I should say that my old Skimmer computer, running an E2200 dual-core Pentium, was distinctly unhappy in contests at 96 KHz coverage of 6 bands, and was absolutely knocked flat at 192 KHz.

I couldn't spend a lot of money, but wanted to do better.  Here's what I came up with:

  • An AMD FX-8350 8-core processor.  This processor has a Passmark score of over 9141, compared to the E2200's 1160.  The AMD is far more cost-effective than Intels of comparable performance, and it even comes with its own cooler
  • An ASUS M5A78L-MLX Plus motherboard.  This is quite an old design, but is the only one I could find that still has onboard video and audio and takes decently fast memory.  And it is really cheap.  I've always liked Asus, not least for their comprehensive user manuals.
  • 8 GB of DDR3 1666 MHz memory.  I have never seen more than about 3 GB of memory in use by Skimmer, but memory is cheap these days, so why not.
I reused my case, power supply, PCI wifi adapter and the DVD drive from the old computer.  Total cost, including a new full copy of Windows 7 Home Premium, was US$ 375.

How does it work?  This weekend, with over 1000 decoders and over 1100 QSOs per 30 minutes, and 192 KHz bandwidth on 7 bands, Skimmer Server was consuming 8-11 percent of the CPU.  I think this bodes very well.

73, Pete N4ZR


Thursday, May 9, 2013

The RBN at Dayton

In addition to N6TV's presentation in the Contest University, the RBN will have a fairly large presence at Dayton this year.  Members of the RBN team planning to attend are Felipe, PY1NB, Dave, KM3T, Dick W3OA, and yours truly.  We'll be wearing RBN Team buttons and giving out RBN buttons to anyone who asks.  Substantive conversation also welcome!

73, Pete N4ZR

Tuesday, April 23, 2013

ViewProp - Innovative Partner with the RBN

For those who may have missed it, ZL2HAM's ViewProp is now available free in a public beta test. Before you yawn and dismiss ViewProp as just another propagation program, hear me out.  This thing is different!

All the propagation prediction programs we are used to - IONCAP, VOACAP and their cousins - are based on historical understanding of propagation.  They make predictions based on solar parameters and their authors quite honestly explain that their results are monthly averages, rather than predictions that reflect what you can expect today or tomorrow.

ViewProp is something new.  It bases its reporting on what is happening today, on paths between your QTH and locations of interest around the world.  It does this by drawing on the Reverse Beacon Network's array of hundreds of Skimmers worldwide to keep track of what is being spotted by Skimmers in your vicinity, as well as what stations in your vicinity are being spotted anywhere else.  The result is a dynamic portrait of propagation from your QTH to and from wherever in the world, which bands are open and how well.




In addition to showing you a map display of the paths being reported, and on what bands, ViewProp also charts the level of activity on different bands over the course of each day in a readily-understandable format. There's much more to it, too, as you can learn by reading the Wiki with more details and a few screenshots here.



I believe this is the first truly revolutionary use of the capabilities of the RBN to promote understanding of your HF propagation.  Try it, and tell us if you agree.  The only thing that Rick asks is that you join the Viewprop Yahoo group at this address, and then you can download the beta version from the group's Files section.

Try it, and tell him what you like, what you don't, and what you think should be added.  I promise you, he is listening.

Monday, March 18, 2013

Two Apps at Once (Part 2)

[Sorry about the bifurcation - the Blogspot editor balked at publishing such a large post.

So, we're back to setting up HDSDR. But first, a quick note on computer requirements to accomplish all this magic.  On my anemic E2200 dual-core Pentium, CW Skimmer is the big load - currently about 30 percent at 96 KHz bandwidth.  RCKSkimmer is burning about 6 percent, and HDSDR is burning about 4 percent.  The rest of the stuff is negligible.  If you want to do what Wes does, and Skim 192 KHz on 7 bands during a contest, you will definitely need more CPU - something with a Passmark of ~9000 is probably about right.  I hope to have one soon.  73, N4ZR] 


Setting up HDSDR
HDSDR originally appeared as "Winrad", written by Alberto, I2PHD.  It has now been further developed by Mario Taeubel in Germany.  The best documentation may be the User Guide by I2PHD as updated by Alan, G4ZFQ.

First let us set up this program so it can be used as a conventional receiver with a pair of headphones.  Since you will eventually have two copies of this software running, make certain you install it in two distinct subdirectories with different names.  I find it useful to immediately create two shortcuts on my desktop with these distinctive names so I do not confuse them.  Now go to the directory where you saved CWSL_Tee, copy the important file, EXtio_CWSL.dll, and paste it into each of the two HDSDR directories.  Make certain Skimmer Server is running.  Now start one copy of HDSDR.  You will get a little window at the upper right that allows you to choose which band HDSDR should demodulate.  And in this window there is this strange parameter called Scale Factor.  Petr points out that Skimmer Server produces 24 bit data but since some programs can use only 16 bit data CWSL trims the data to 16 bit.  The Scale Factor specifies which bits to retain after trimming.  For our purposes you need to choose some value between 16 and about 10.  I use the highest number that gives me noise in the waterfall when the band is "dead"  Try 13 for a first attempt with an HF band



 Go to Sound Card, ignore the "RX Input (from Radio) since the input from the radio is controlled by the EXtio_CWSL file.  For "RX Output (to Speaker)" select the sound card you use for audio from the internet, for example.  Select Bandwidth.  If you are using 192 khz bands in Skimmer Server you should get something like this:




 You may want to temporarily select a different Output Sampling Rate for the soundcard you use for your headphones but eventually it is best if the Input rate can be evenly divided by the Output rate.  For use with RCKskimmer select an Output Sample Rate of 48000 Hz, not 12000 as illustrated above.

Click Options / Select Input.  It should already read "CWSL".  Now you should be able to start the program and tune the frequency by clicking on the waterfall or clicking on the digits in the LO frequency and then the Tune  digits.  Some "gotcha's" -- clicking on the S-meter determines where the squelch level is set so be careful you don't squelch the receiver and then wonder what is wrong.  I also have spent hours trying to solve problems when it was squelched or the Mute button or the wrong mode button was pressed inadvertently.  After you have played with the program, perused the User Guide, figured out how to set the filter width, etc., we can go on. 

Our next tasks are the same as we would face installing RCKskimmer on any conventional HF receiver.  We need to get the audio out of the HDSDR receiver and into the RTTY decoder.  Also we need to set up Omni-Rig and its com ports so RCKskimmer can change the frequency within HDSDR's selected band. 

Installing RCKskimmer
Go to Walter's web site at http://www.walter-dallmeier.de/software-by-dl4rck/rckskimmer/ and download the program as well as his "Predefined Search-Frequency Setup" files.  While you are there you probably will want to join his email forum where the program is supported.  Install the software in two differently named subdirectories and put distinctive shortcuts to the two instances on your desktop.   When the installation program asks whether it should install Omni-Rig say "Yes".

Installing the plumbing
Return to your first instance of HDSDR and select Soundcard.  Ignore the "RX Input" but change "RX Output" to Line 1 (Virtual Cable).  Make certain that HDSDR is in LSB mode with a filter bandwidth that is appropriate (2.6 to 3 khz). 

Now go to "Options".  This is a confusing step.  We don't  want "CAT to RADIO (Omni-Rig)".  That is because we are not using Omni-Rig to send controls from HDSDR to the QS1R -- that is the job of  the EXTio_CWSL file.  We do want to set "CAT to HDSDR" because we need CAT control between RCKskimmer and HDSDR.  Here set the port to Port 11, the Baud rate to 9600, PTT Activation to "None", and then, importantly, click "activated" to turn it on.  (Note that the Port sub-menu goes "grey" when the "activated" button is pressed



 Now let's go to RCKskimmer.  Under "Setup / Program Setup / Digi Module" you will see




UNLIKE the illustration, unclick the "Enable Telnet Server" and the "Send your received spots to RCK-Cluster" until you have everything working and are confident your spots are correct --  another "gotcha".  Fill out the information to the left and select as the Sound Card Device, Line 1 (Virtual Audio Cable).  UNLIKE the illustration, set the Soundcard Sample Rate to 48000, not 12000.

Change the check marks to correspond with the illustration in the lower left.  Since telnet port 7300 is probably being used by Skimmer Server, change this Telnet Server port to 7200.   Eventually the second instance of RCKskimmer might use port 7100.

Note that it is important to have the check in the box for "Additional use Master Call data for detection."  A check here lowers the validation requirement for call-signs that are in the database but does not prevent detection of calls not in the database.

Now let's go to the tab "TRX Control".  Under "Omni-Rig Control" click "Use Rig 1" and then "Settings"

.

HDSDR emulates a Kenwood.  So select that in the "Rig type" menu and fill in the rest of the Window.  Then click "OK"

IN the "Search Options" tab I use the following parameters





On "Jump Stepp (Hz)" select 2400 hz.  Even though you can select a wider bandwidth Walter says the program does a poor job of decoding the edges and he says to leave it here.   It may be my imagination but I think HDSDR seems to introduce some latency and I think I get better results when I use the values of 5, 7 or 8, and 20 seconds instead of the default dwell times.  

Now go to the "Search Frequencys" tab.



Here select a frequency range that lies within the band that HDSDR is demodulating.  The "Use Advanced Search Mode" changes the bands as the propagation changes during a day so we can't use that feature because we can't conveniently change bands. To use your customized dwell times instead of the default values you must select "customized" under "Search Type"

The illustration above shows only one frequency range chosen.  But you could easily add the 14070  BPSK range as well if you wanted to skim for both modes on the same band.  If there is a lot of US domestic RTTY traffic around 7.08mhz  I often have two RTTY frequency regions in my 7mhz  RTTY skimming.

OK.  You should be ready to press "Start" and watch the waterfall decode RTTY signals. 

Remember, once again, Skimmer Server must be started and the FPGA loaded before you start HDSDR.

Install a second instance of HDSDR and RCKskimmer
Now repeat this process, configuring your second instance of HDSDR and RCKskimmer using the com port 13-14 pair, virtual audio cable line 2 and telnet port 7100.  Another "gotcha" --  in HDSDR the settings for Sound Card and CAT to HDSDR port sometimes get confused when you close an instance of HDSDR and then restart it.  Always check these settings when starting the program so you don't send the audio to a copy of RCKskimmer that thinks it is scanning a different band.

Calibrating the frequency in HDSDR
Eventually if you are as compulsive as I am you will want to calibrate your receiver to make certain the RTTY spots report correct frequency.  If you have been running Skimmer Server you undoubtedly have arrived at a FreqCalibration number in your ini file that gives you respectably accurate CW spots.   For example, on my QS1R this value is currently 1.0000085 which is the ratio of the Displayed Frequency divided by the True Frequency.  If I understand things correctly, this correction is applied in the PC after the CWSL_Tee so your RTTY spots are uncorrected.  To apply this correction to each instance of HDSDR tune the software to some frequency, say 14090000hz, and navigate to "Options / RF Front End + Calibration".  Now tell the software the "true" frequency is 14089880 (Tuned freq / SkimServer FreqCalibration or 14090.000 / 1.0000085).

Setup WinTelnetX to funnel spots to RBN
If everything is working correctly, you now have spots from three sources: Skimmer Server and two instances of RCKskimmer.  How do you get the spots to the RBN.  I use K1TTT's WintelnetX to funnel all the data together into Aggregator.  That is the topic of my last previous blog post.

Where can I find RTTY skimmer spots?
Currently there are RCKskimmer operators who send their spots to Walter's DL4RCK DX cluster who don't yet send them to RBN.  However, many of the DX clusters which carry RBN skimmer spots also are picking up all the spots from Walter's site.  To check whether your favorite skimmer DX cluster has all of Walter's data, you can Ttelnet to his site, dl4rck.ham-radio-op.net  port  8000, and give the command "sh/fullinfo" to get a listing of users.

WZ7I Skimmer Current Configuration
Recently I needed to purchase a second QS1R to use in recording contests.  But since contests aren't on the air all the time I am using the second SDR to cover more CW and RTTY bands.  So the current installation here is both QS1R receivers, each running multiple bands on Skimmer Server and two bands of RCKskimmer, for a total of four bands of RTTY skimming.  All the telnet data goes into WintelnetX and Aggregator.  




It isn't pretty but it works.  The white things are metal drawer dividers for silverware from the local hardware store house wares department which I purchased after my wife inexplicably asked for her cake cooling racks to be returned.  On the front rack are two-way and a four-way Advanced Receiver Research power dividers, then the KD9SV Front End Protector from http://www.radio-ware.com/ and finally a Clifton Laboratories Z10046A preamp.  This is fed from a HyGain Hy-Tower vertical.

Good luck and let me know if I can help or if you see errors.

73, Wes, WZ7I