Rename SkimSrv.exe to SkimSrv2.exeRename CWSL_Tee.dll to CWSL_Tee2.dllRename HermesIntf_xxxx.dll to HermestIntf_FFxx.dllUpdate CWSL_Tee.cfg:HermestIntf_FFxx64
Sunday, February 28, 2021
Monday, November 16, 2020
Bjorn, SM7IUN has brought my attention to a potentially important caveat in editing the start.sh file to activate two entirely separate receivers on an RP-16.
The RP-16 is a Linux device, so the start.sh file must be compatible with Linux. However, if you edit a Linux file using Windows Notepad, the edited file will come out with <CR><LF> at the end of each line, rather than the Linux standard <LF>. This, in turn, could result in its no longer working under Linux. While I have not yet had this problem with my RP-16s, it's worth knowing about.
Fortunately, there is an easy solution - Notepad++. Written by Don Ho, it is freeware, and senses whether a file selected for editing follows the Linux convention or the Windows and ends lines appropriately. A worthwhile precaution, I'd say.
Sunday, November 15, 2020
As outlined in my post a couple of weeks ago, it is not possible, using a single Aggregator, to post spots from the two receivers in an RP-16 to the RBN under separate receiver names. Fortunately, Dick Williams, W3OA, the author of the Aggregator, has figured out a work-around. Here's his solution:1) Update Aggregator to version 6.2. Aggregator will now show the name of its executable file in the title bar at the top of its window. This enables you to determine which Aggregator instance the window refers to.
2) Aggregator was running from C:\Ham Stuff\Aggregator. I created a new folder, C:\Ham Stuff\Aggregator2, and copied Aggregator.exe from the original folder to the new one. Also copy BADCALLS.txt if you are using that filter.
3) Rename Aggregator.exe in the new folder to Aggregator2.exe.
4) In your first Aggregator instance go to the “Secondary Skimmers” tab, find the line which connects to the second SkimSrv instance, click the “D” button, and uncheck the “Auto Connect?” box.
5) Again in your first Aggregator instance go to the “FT#” tab and uncheck the “Use?” box for each source which receives spots from the “Rig Numbers” on the right half of the FT#StartUp window, i.e SkimSrv2. Then click the “Apply Changes” button.
6) In your second SkimSrv instance go to the “Operator” tab and update the entries there as necessary. The callsign should be the SSID you want to use for that Skimmer. (I used W3OA-2.)
9) Return to the first Aggregator instance, go to the “Associate Pgms” tab, and add the second Aggregator instance.
Ash KF5EYY/3V8 just reminded me of an additional requirement for running both receivers on an RP-16, to cover 8 bands each. Each receiver requires about 75 Mbps of Ethernet bandwidth between the receiver and your PC, and it adds up. This means that your PC must have a gigabit Ethernet port in order to receive two receivers worth of 8-band x 192 KHz data.
My PC has such a port, but like many it was already committed to my Internet router. Fortunately, Netgear makes a very nice unmanaged Ethernet switch, the GS 308 which retails for under US$20 plus shipping. All I had to do was plug my receiver, my PC, my KPA-1500 amp and my router into the switch, and it was up and running. Whew!
Monday, September 21, 2020
The RP-16 has a hidden, bonus capability – it can run a second, 8 bands x 192 KHz receiver alongside but independent of the first. This capability has a lot of potential uses – I often use it for comparing two antennas. I have also used it to run RTTY Skimmer Server along with CW Skimmer Server on a single antenna, without having to resort to CWSL_Tee to share the output from a single receiver . Many operators use it to expand coverage on CW or RTTY to as many as 11 or 12 bands at once, or to add FT4 or FT8 capability.
One caution, to be mentioned first for emphasis– if you run two Skimmer Servers on the two receivers of the RP-16, do not try to send spots from both to the Reverse Beacon Network. You would think that by identifying the Skimsrv operator by two different callsigns, like W8QZR and W8QZR/3, for example, they would appear separately on the server. The problem is that the RBN Aggregator is only capable of reporting one operator callsign to the RBN server, so each spot will be attributed to one call, and any stations that both receivers spot will appear twice. This is a function of how the Aggregators communicate with the server and, at least for the moment, cannot be changed.
Of course, this caution does not apply to running CW Skimmer Server on one receiver and RTTY Skimmer Server on the other, since their modes are different. It also obviously does not apply to using one receiver on one set of bands, and the other on different ones, as you might do to optimize receiving or covering 6 meters along with HF.
There are two options for the second receiver – it can either share the antenna with the first receiver, or it can use the second input on the RP-16 to connect a separate antenna.
When you boot up the RP-16, it starts two separate receivers and connects them to two different IP addresses. From there on, it’s up to you – you can connect a separate instance of Skimmer Server (see below), or any SDR that can use the Hermes_intf.dll. The only one I have tested this with is HPSDR.
To use a separate antenna on the second receiver, put the RP-16’s SD card in your reader and bring up the start.sh file for the hpsdr-compatible receiver in your text editor. It is pretty short and simple, and will look like this:
cat $apps_dir/sdr_receiver_hpsdr/sdr_receiver_hpsdr.bit > /dev/xdevcfg
address=`awk -F : '$5="FF"' OFS=: /sys/class/net/eth0/address`
ip link add mvl0 link eth0 address $address type macvlan mode passthru
echo 1 > /proc/sys/net/ipv4/conf/all/arp_filter
echo 2 > /proc/sys/net/ipv4/conf/all/rp_filter
$apps_dir/sdr_receiver_hpsdr/sdr-receiver-hpsdr eth0 1 1 1 1 1 1 1 1 &
$apps_dir/sdr_receiver_hpsdr/sdr-receiver-hpsdr mvl0 1 1 1 1 1 1 1 1 &
All we are concerned with is the last line, and to activate the second receiver on its own antenna all we need to do is change each of the “1”s in that line to a “2”, So it reads "$apps_dir/sdr_receiver_hpsdr/sdr-receiver-hpsdr mvl0 2 2 2 2 2 2 2 2 &”. Save the file to your SD card, and the second receiver is ready to go, on its own antenna.
In order to run Skimmer Server on the second receiver, you’ll need to create a separate instance of Skimmer Server in your computer, with a different name, and also rename the executable. What I did was to install it under the program folder name “Skimsrv 2”, and rename the executable from Skimsrv.exe to Skimsrv2.exe.
There’s one final thing to be done before you start the two simultaneous receivers. In the first Skimmer Server program folder, find the Hermes_Intf.DLL. Rename it to explicitly recognize the first receiver. The MAC address of that receiver is printed on top of its Ethernet connector. You need to copy the right-most four characters of the MAC address, and then use them to rename the Hermes_Intf.dll file. In my case, it became HermesIntf_7c93.dll. Don’t forget the “_”.
Now go into your second Skimmer Server directory and rename its HermesIntf.dll, in this case replacing the first two characters of the MAC address with “ff”. Rename the HermesIntf.dll as you did above for the first. In my case it became HermesIntf_ff93.dll.
And now, finally, it’s ready to go. Start CW Skimserv on the first receiver. Go to its Skimmer tab and verify that it has the correct address, like this:
Now you can connect a second antenna to the second SMA input connector on the RP-16 (next to the first one), and you’re off and running. You can get data from either receiver using a Telnet program like Putty – be sure they have different Telnet addresses on the Telnet tab in Skimserv. You can also use the Aggregator’s Skimmer Traffic tab to follow what each is spotting, but if you do that, be sure that you check the “don’t send spots to RBN server” box on the Connections tab (far left side) and set up the Secondary Skimmers tab with the right (different) Telnet port number to connect to the second instance of Skimsrv.
Wednesday, June 17, 2020
Monday, April 27, 2020
Once I had the second receiver running on my 122.8-16 Red Pitaya, I decided to explore methodology for comparing antennas. I hope this may be of interest, and would welcome any critiques of my technique.
Both antennas are installed on non-conductive poles, the Mini-Whip at 8 feet above ground and the Clifton Labs active whip at about 12. Each antenna is grounded to an 8-foot copper ground rod at its base through insulated wire taped to the pole. My particular Mini-Whip is from a supplier in the Ukraine, Transverters-Store. He says it follows the latest PA0NHC improvements on the original design, and provides a schematic to prove it. The Clifton Labs active whip is a prototype produced by Jack Smith, K8ZOA (SK) about 10 years ago. So far as I can determine, it is operating normally.
Because everyone seems to agree that noise reduction is critical to these types of antenna, I wound the feedline coax on Type 31 "big snap-on" cores at both ends of the feedline to the mini-whip, and on the shack end of the feedline for the Clifton whip (I ran out of cores). I am sure these chokes can be improved upon by winding smaller coax or insulated wire on cores, permitting more turns and better isolation. HPSDR suggests that noise coming in from the antennas is roughly the same, about -125 dBM. The band noise as received on my Carolina Windom was a few dB higher, at around -122.
For purposes of this first comparison, I ran the two antennas simultaneously for about 21 hours on 80-12 meters. Results:
Number of spots: Mini-whip 2558 Clifton whip 2094
Average SNR: Mini-whip 14.7 dB Clifton whip 13.8 dB
Why such a large difference in the number of spots, for a relatively low difference in average signal-to-noise ratio? I thought at first that the answer would be that spots were not evenly distributed among bands, and the antennas' performance was better on some bands than others. Back to the data:
Spots by Band
Band with the mini-whip, with the Clifton whip
80 628 649
40 1254 1073
30 224 214
20 440 252
17 5 0
Band mini-whip Clifton whip
80 20.3 16.9
40 13.8 13.8
30 13.0 13.7
20 10.3 10.6
So that hypothesis doesn't really work out either. More questions than answers here, I'm afraid. The biggest difference in spots was on 20 and 40, yet the average SNR was identical on 40 and only 0.3 dB different on 20, but in the wrong direction. The mini-whip outperformed the Clifton whip on 20 by 188 spots, despite being 0.3 dB inferior in average SNR.
My full-sized Carolina Windom out-performs both smaller antennas by a large margin. But if you can't manage a large antenna, the mini-whip is an acceptable and very low-cost option.