The SOTA Cluster

SOTA President John, G3WGV suggested I remind both longtime SOTA operators and the many new operators about the SOTA Cluster.

The SOTA Cluster is a DXcluster look-alike but instead of taking spots from its users like DXcluster, SOTA Cluster is fed entirely from the same spot source as SOTAwatch. What this means is it is a duplicate of the spots on SOTAwatch however as the output format looks liek DXcluster it is easy to integrate this with the many logging programs in use. I know that it integrates with Windows, Mac and Linux logging programs. Those who have set their logging program to control their radios can point and click on the spots from the SOTA Cluster feed and have their station rigs tuned to the spot frequency.

The cluster can be found at the following address & port number “cluster.sota.org.uk 7300”. Put those numbers into your logging program to make use of the feed. The cluster uses a simple raw network protocol so you can connect direct from a console, this is how I use it here and on Linux I use nc like this “nc cluster.sota.org.uk 7300”. You need to provide your callsign but you don’t need to provide a password.

The following commands are supported:

sh/dx - this shows the last 25-50 SOTA spots received.
sh/users - this shows the current user list
ping5 - this causes the cluster to send you a prompt every 5 minutes
ping1 - as ping5 but the prompt is sent every minute

ping5 and ping 1 are useful for people with home routers that shutdown connections when there has not been any traffic for a while on the link. i.e. if there are no spots for an hour, your home router my silently close the connection and you would not know. Use a ping5/ping1 in conjunction with your program’s KEEPALIVE connection timer.

Here is a typical login screen:

someone@somebox:~$ nc cluster.sota.org.uk 7300
Welcome to the MM0FMF SOTA Cluster
This is version 8.10 built 14th July 2025



Set your keepalive pings to no less than 15mins

login: gm3pyu

GM3PYU de MM0FMF sota_cluster >
DX de CT2GSN:    14185.0  CT2GSN/P     CT/TM-039                      1315Z
DX de S57MS:     50153.0  S57MS/P      S5/PK-002                      1311Z
DX de G4OBK:     10122.0  F/G4OBK/P    F/MC-183                       1311Z
DX de DL6GCA:     7028.0  DL6GCA/P     DM/HE-097                      1309Z
DX de DH2ID:     14282.0  DH2ID/P      DM/BW-639                      1304Z
DX de G4OBK:     14062.0  F/G4OBK/P    F/MC-183                       1302Z
DX de HB9EVF:    21061.0  HB9EVF/P     HB/ZH-017                      1302Z
DX de HB9EVF:    10123.0  HB9EVF/P     HB/ZH-017                      1249Z
DX de S52AU:      7029.3  S52AU/P      S5/CP-005                      1315Z
DX de G4OBK:      7032.0  F/G4OBK/P    F/MC-183                       1316Z
DX de S57MS:     28360.0  S57MS/P      S5/PK-002                      1318Z
DX de S57MS:     14307.0  S57MS/P      S5/PK-002                      1325Z
DX de CT2GSN:    14185.0  CT2GSN/P     CT/TM-039                      1327Z
DX de F6HBI:    145500.0  F6HBI/P      F/AM-313                       1331Z

GM3PYU de MM0FMF sota_cluster >

And here is the current user list.

GM3PYU de MM0FMF sota_cluster >
sh/users
Node         Callsigns

MM0FMF       ON6ZQ        DO1ZL        2M0RVZ       HB9HBV       IV3DXW-2
             ON6ZQ        W4GO         VE3HYK       VE2KVU       PA0B
             PA7RA        W0CP         WB6POT       OK2PDT       HB9HDC
             KK1W         K5CPR        GI4ONL       VE3VRW       W1WRA
             VE3VRW       VE3VRW       GI0AZA       VE3VRW       PF2X
             CT1DRB       CT1DRB       AF9W         GM3PYU
GM3PYU de MM0FMF sota_cluster >

I have fixed a bug today that allowed QRT or TEST spots through, they used to appear with the frequency 0.0 but they are now suppressed.

If you have any questions or suggestions, then drop them into this thread.

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Thanks for the reminder Andy. If I could do more chasing it would be very useful.

Maybe add an info article here: https://www.sota.org.uk/Joining-In

Not every newcomer is reading the historic Reflector postings.

73 Joe

5 Likes

Chase what you can Joe and Completing becomes an addiction (That’s what happened to me) if you are not careful!

Thanks to Andy & John for this useful reminder. The SOTA Cluster is always connected all day when I am at home and I mix the SOTA spots with filtered DX spots from the VE7CC window in the same window logging programme (DX IN RED and SOTA IN BLACK). Works superbly for me and I am very grateful for you Andy @MM0FMF for providing this service. Surely its a pint for you the next time we meet up in a licenced premises!

73 Phil G4OBK

3 Likes

Two different experiences:

1 Linux

I can get into cluster.sota.org.uk 7300 using either nc or telnet from my RPi5 running Debian Bookworm; no problem.

Also, for comparison, I can likewise get into the regular cluster dxspider.co.uk 7300 using the same methods.

2 Windows 11 Home

I installed the Telnet client which, as many will know, is not part of the standard install.

I can get into dxspider.co.uk 7300, and it works no problem.

When I connect to cluster.sota.org.uk 7300, I get to the login: prompt, but typing a single character (and no RETURN) causes the connection to be lost - see image below.

Not sure why? But the late G3NYY reported a similar problem on the Reflector back in 2018/19 using the Telnet client from Win7 Pro.

Don’t know if this ever got resolved?

73 Dave

PS I believe Windows tends to use UTF-16 characters (2 bytes minimum) to accommodate the languages of all the countries for which it can be ‘localised’. Linux uses UTF-8 characters which are typically just a single byte for A-Z, 0-9 and a few more. May not be relevant?


1 Like

Yes it doesn’t work. Sadly not ideal for Windows users.

I was looking at this earlier today and am working on a solution but do not having anything yet.

1 Like

Putty works on Windows 11. I had to set Passive mode in the Telnet config.

After few tests, likewise for me, using Putty in RAW mode.

73 Dave


Thanks for the comments. I’m in the process of divorcing myself from Windows, I have a nice W10 Pro desktop that wont run W11 and having run W11 on Mrs. FMF’s laptop and my work laptop I have absolutely no desire to inflict more W11 nonsense on myself. Hence, and I’m sorry for those who are into the MS CoolAid, I wasn’t bothered that the console experience on Windows is not so good. There I’ve come out and said it, Windows is a second class target for me.

Now I know I have written in the past about Raw mode and PuTTY but when writing the initial post earlier today, Raw mode would not work. Just wouldn’t. Seeing Dave got it going all I could think was I had updated PuTTY since I last tried, so maybe this version has a Raw mode bug and so I updated to v0.83 and it now works in Raw mode. Also in Telnet passive mode on PuTTY 0.83.

Someone asked why it doesn’t support proper Telnet and the answer is finger-trouble and incompetence on my part. I tried sometime back to make it work with a Telnet library and failed and lost interest as it worked for me on Linux with netcat (nc) and it was working with all the logging programs on Windows, Mac & Linux. Apart from HRD that is. Given HRD owners hit me, my personal web hosting company and SOTA’s old hosts with DMCA takedown notices because I was making the old free versions of HRD available and wrote about on here, Hell will freeze over before I help make HRD more usable :wink:

So no Telnet support at present, sorry. But I’ll have another ponder about making it work with Windows Telnet.

2 Likes

Consulting the Oracle (Greek mythology, not database) … Putty RAW is apparently just TCP without the Telnet layers:

73 Dave

2 Likes

Thanks for this reminder.
I tried with my Contest logging program DXLog.net + DXLog.Net Client.
Thats very fine.
Gerald F6HBI

1 Like

The other (and in my view the best) solution for Windows users is to install WSL (Windows Subsystem for Linux). It’s provided by Microsoft and is available from the Windows Store (free).

It provides a complete Linux environment fully integrated with the Windows filesystem. It’s no trouble at all to flip back and forth at will between Windows GUI tools and the Linux command line. It has been a complete game changer for me; I still run a Linux VM but hardly ever need to use it.

Specifically, the “nc” command we’re talking about here just works.

Martyn M1MAJ

2 Likes

Yes, it’s very useful both as WSL and the later WSL2. It was also a game changer at work where staff have Windows (W11 Enterprise) laptops but 85% of the work we do is written on and for Linux machines. It meant you could do quite a lot of work on WSL instead of connecting into the compute-farm machines. However, we had a diktat from the IT goons that it was no longer to be installed and used because it allowed us to be too efficient at our jobs. :rofl: No, it wasn’t allowed because we could bypass lots of the security spyware and access constraints IT placed on user machines which allowed us to get the jobs done without petty restrictions making life harder than needed.

But WSL (either version) is well worth having. But the boys from Seattle have forced their last UI changes for no-good-reason on me for the last time. So this W10 image will be turned into VM and run on a yet to be purchased new PC. I just have to decide which Linux desktop to use.

Hi all,

I was wondering if there’s currently any way to receive QRT messages (or similar status updates) via the SOTA Cluster at cluster.sota.org.uk:7300.
It would be really helpful to know when an activator has gone QRT when monitoring activity through the cluster interface.

Thanks!

73, Alberto EA3GNU

Sorry no. There would be no way of indicating the QRT status either.

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OK. And any other way of getting that info? Via API? Thanks!

So that’s what its for, so you can link clusters to logging software and then use to CAT control your radio and auto log.
As I don’t use logging software or CAT control my radio…I had assumed it was for cluster software to exchange info.

Every day is a school day.

Ta.
John

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