Last Updated on April 7, 2026 by g6nhu
In order for your HamClock to work after June 2026, you must switch to a different backend server.
Since my original post on the future of HamClock, a number of very talented people have been hard at work in examining the traffic to and from HamClocks and the host server and reproducing it.
First of all, a bit of an explanation as to why this is needed. The HamClock server handles almost all traffic between end user HamClocks (the devices you have in your shack) and the outside world. Everything your HamClock displays except the dxcluster (and you should be using dxspider.co.uk on port 7300) goes through the home server. This is done for a number of reasons, the main one being avoiding adding additional load on the data sources. There are well over 10,000 active HamClocks out there, imagine all the extra traffic if those HamClocks were all polling pskreporter, or the POTA/SOTA sources, or the sites that generously provide the space weather figures. By handling it all centrally, it adds minimal load on the sources.
I was surprised when I was originally told that even the maps are generated on the server. If you click to select a different map, the calculations to overlay DRAP/Aurora/MUF or whatever are all done at the host and the raw image file is sent to your HamClock to display. This has the benefit that HamClock runs on very low powered devices, even a Raspberry Pi Zero. It’s the same with VOACAP, every time you click to change the DX location, the VOACAP predictions are done on the server. To say that Elwood was incredibly talented would be an understatement.
Technically, it might be possible to modify HamClock to connect to the sources manually and generate the maps locally but that would include a massive load on the data sources and the CPU on many devices simply isn’t up to the task. You’d try and switch maps and it could take five minutes to appear. Going this way isn’t a practical solution.
So the team are working to reproduce all the data from the server by watching the network traffic, reverse engineering it and replicating it to your HamClock.
It’s only been a month since Elwood became silent key but the project is progressing rapidly and I’m happy to be able to provide more details.
HamClock is not dead. I can state that categorically now.
I mentioned Open HamClock Backend (OHB) in my last post and it’s now at a stage where people can connect to it and give it a try. OHB is a completely open source project. This means the code is fully available for anyone to access, completely free of charge. If you’re able to help with the development, your input is welcome, but equally so, if you just want to use it, that’s perfectly fine as well.
Because it’s open and being developed by multiple people, it means it’s not reliant on a single person any more. If anything happens to one of the devs, there are others.
A very kind radio amateur has donated an appropriate server and the bandwidth needed for OHB. Again, multiple people have access to this, it’s not just one person as before. If anything happens to one of the team, there are others who have access.
Losing Elwood was tragic and I’m still struggling to come to terms with it. We were exchanging emails up to a few days before he became SK and I simply had no idea. I’m sure he would want HamClock to continue, he added something specific to the newest version to allow it to carry on.
If you’re using an Inovato Quadra, either the original model or the newer 4K version, or a Raspberry Pi, or any linux based device to run HamClock, you can switch to the new server I mentioned above. I will be providing simple instructions below, along with instructions to reverse the changes made if needed.
But first, some screenshots of OHB. These are all taken from my master HamClock connected to the OHB server. Please note the the original post of this article had the wrong screenshots, I noticed this a few hours later and corrected it.
That’s a lot of screenshots and it’s done to show you how OHB looks now and to show everything working. If I’ve missed anything you’d like to know, please tell me in the comments and I’ll add to this.
There are actually two available backends for HamClock, the screenshots above are from OHB, the other is run by Bruce W4BAE and he describes it in detail at his site.
Changing the backend on a Quadra using the built in utility
I originally described how to manually edit the configuration on a Quadra but it’s now built in to the device so I’ve removed my instructions.
Udo, N0LSR has written a fantastic guide to this where you can choose either OHB or Bruce’s hamclock.com backend. You can see it here or download it as a pdf file here.
Changing the backend on a Raspberry Pi – Install the script
I’ve written some scripts which make it really easy – You don’t even need to quit HamClock. This should work on a Pi, or a Quadra (although the built in utility works well).
Open a terminal and run this command which downloads and installs the scripts. If you’re asked for your password, it’s your usual logon password (1n0v@t0 for a Quadra).
curl -fsSL https://hamclock.co.uk/tools | sudo bashIf you can’t find the | symbol on your keyboard, it’s often with the backslash and will look like one of these. The version on the left is most common but it could be either.
If you’re using Raspberry Pi OS Trixie (or newer), enter the following command. If you don’t know what version operating system you’re using, enter it anyway. It won’t run on an older operating system and if nothing needs changing on Trixie, it won’t do anything. Without this, /etc/hosts will reset itself after a reboot if you’re using Trixie.
sudo fix-hostsYou will get one of three responses:
If you were prompted to reboot, do so now.
sudo reboot nowSelect a backend for HamClock
Open-hamclock-backend (OHB) – For full details see here and here. This is an open-source backend being worked on by a group of radio amateurs. You can either run an instance yourself, or if you’d rather, you can simply connect to their server.
Hamclock.com (HCDC) – For full details see here. This is a closed-source backed being worked on by a single person. You can’t run this yourself but you can simply connect to his server.
Log back into your Pi (or Quadra, or whatever) and open a terminal.
Switching backends is very easy using the scripts I’ve provided.
To select the Open HamClock Backend, type the following:
sudo ohb
To select the Hamclock.com Backend, type the following:
sudo hcdc
You can only have one backend active, the scripts will take care of that. If you want to find out which backend you have selected, use the following command:
what
If you want to know more about the OHB project, the full source code and full instructions about how to run your own backend are available at the GitHub site here: https://github.com/komacke/open-hamclock-backend or at https://ohb.works.
As well as the two projects described here, I’ve heard of a third one which claimed to be nearly complete after just a couple of days but there’s no other sign of it yet. It claimed to be moving all the links and processing onto the local device and I’ve already said above why I don’t think that’s a good idea.
Thanks to the many people working on keeping HamClock alive and to those who are supporting them with their help and assistance.
Please remember that all these projects are still being developed and enhanced. HamClock ran for many years and had tens of thousands of hours of development. Reproducing the backend server in the time taken so far is incredible progress.
Terrific news, thanks all.
I’d like to respond to the recommendations being made here. I’ve written up a detailed response on my website addressing the claims about the HamClock backend situation — what’s accurate, what isn’t, and who’s actually building what.
Please have a look: https://hamclock.com/facts-not-fables.html
73 de Bruce, W4BAE
Everything was hand coded by me mostly in my spare time. We don’t proxy anything with hamclock dot com fortunately. Only proxy VOACAP to clearskyinstitute until I can get it to match original HamClock. I was transparent about that in our GitHub.
https://github.com/BrianWilkinsFL/open-hamclock-backend/blob/main/scripts/update_aurora_maps.sh
https://github.com/BrianWilkinsFL/open-hamclock-backend/blob/main/scripts/update_cloud_maps.sh
https://github.com/BrianWilkinsFL/open-hamclock-backend/blob/main/scripts/kc2g_muf_heatmap.sh
https://github.com/BrianWilkinsFL/open-hamclock-backend/blob/main/scripts/update_drap_maps.sh
(working as of three weeks ago)
VOACAP engine I pulled because it’s not accurate. It’s still in there just bypassed.
All of our scripts are there and we did email you and send you a message on FB. I am not sure what is going on here. My email is on qrz if you would like to reach out and discuss further.
Morning Bruce.
When this article went live yesterday afternoon, I’d taken screenshots from my HamClock connected to OHB but there was an error in my own config and you’re right, the maps were not indicative of the OHB output.
I realised this in the evening and immediately corrected it. You can see from the time on the images now that they were all updated around 23:00z, several hours after I originally posted this piece.
And it’s very clear to anyone that they’re new maps, not pixel perfect with the CSI maps. It’s not just the map output that’s different to CSI either.
I have no financial involvement with anything to do with HamClock. Never have, never will.
All I want is for everyone to be able to use HamClock past June, no matter what method they use. It’s a simple as that.
73 Keith.
Also, I’ve made no claims about your hamclock backend situation. In this article, I’ve simply mentioned it’s available and provided a link. Literally nothing else.
I’ve just updated my RPi HamClock setup guide (as I do regularly) with instructions to picking a backend server, giving a complete choice.
Frankly, I don’t care what people use. I don’t want to get involved with arguments as to which is ‘best’ because ultimately, everyone is working towards the same goal. I wish everyone would just get on.
This is wonderful. It also works on Mac. I just opened a terminal and sudo nano /etc/hosts.
How does this affect ESP32 Ham Clock?
Good question, Roger.
I really don’t know how to fix an ESP based clock. My best suggestion would be to contact Gino at Veritium who may be able to help.
https://veritiumresearch.com/hf-clock/
Mine isn’t a commercial product, it’s homebrew. The firmware is fairly complex to wade through to find the links to the server and I was hoping someone might have been there before me. Guess I’ll have to carry on digging!
I understand, but I know Gino and I’m sure he’ll be happy to offer advice as he’s probably the most experienced person regarding the ESP version, whether commercial or based on the original QST version.
I did ask him about this a few days ago and he mentioned that something might be doable via the RESTful network interface via 2.4G WiFi connection.
I have a homebrew ESP8266 HamClock, running version 3.10. I did find one line in wifi.cpp, that if you change clearskyinstitute.com to either ohb.hamclock.app or hamclock.com it should vector to those sites instead. You need to use the Arduino IDE to compile and upload the revised code into the Hamclock. I haven’t tested this yet, waiting to see how the development is going first
Good news for everyone who’s asked “what happens if something happens to you?”
Philip Gladstone — the man behind PSKReporter.info — has agreed to serve as trustee for hamclock.com. Domain, DNS, and infrastructure access are being provisioned shortly.
No single point of failure. Not anymore.
https://www.hamclock.com/continuity.html
Is there any difference in running the HamApps installer than just editing the /etc/hosts file manually?
No, it’s effectively the same thing.
Keith, G6NHU — and everyone here — a brief note before I share this link.
Keith, I owe you a correction. I incorrectly stated that you posted on Facebook. You posted on your own blog, which is entirely your right, and I should have gotten that right before publishing. I also want to say that your bug reports and feedback have been genuinely valuable — every one of them has been useful and is appreciated more than I can adequately express. Thank you for that.
We don’t see eye to eye on everything, and that’s fine. That’s how a healthy community works. I’ve put together a detailed post covering what’s actually been happening behind the scenes at hamclock.com — the technical evidence, the forensics, and where things stand. I’d ask that you read it with an open mind.
https://www.hamclock.com/news.html
73 de W4BAE
I can’t comment about connections to your server over that period because I simply don’t know.
However OHB proxying from Elwood’s server is correct. Nobody is saying this doesn’t happen, it’s mentioned on the GitHub site and Brian said above in a reply to you what’s happening with this. I don’t believe it’s much, it’s being done while work continues in the background to get all the feeds as close as possible. It’s not a secret that you’re telling everyone, it’s already public knowledge.
73 Keith
I don’t operate an OHB server or have an account on one. The server you’re referring to is run by another ham in the community, so it isn’t “Brian’s server.” I’ll let the operator of that system respond if needed.
All of the OHB code is publicly available and open for anyone to review or use.
VOACAP work is still in progress, as noted previously.
I’m not aware of any connections to your server during the timeframe you mentioned.
Look under application # 99677866 for the USPTO. Why did Bruce want to file a trademark for HamClock for something he didn’t invent? Why does he want to monetize HamClock? What else is he hiding?
So happy that OHB is the first backend replacement that has 100% parity with Elwood’s original backend and feature complete ahead of the June date beating out all competition. Check out the latest version from the link above!
Hello all
I have tried multiple times going through the steps published in this email a couple weeks ago and after I push cntrl,alt,delete and the little window opens that says xscreensaver and then says user name quadra and it asked for a password and I put (1n0v@t0) (yes I did use zeros) and then the little window goes away and all I get is the regular start up screen with the icon bar at the bottom and a little icon in the upper left and then at the very top left it has a app drop down list. I do not ever get a window to change anything else.
I am running the latest and newest INOVATO Quadra that was one of the last ones he sold before closing the internet sales down. Hopefully Mr. Brown has been able to spend time with his friends and family. So, if someone has a suggestion on what I am not doing correctly please help me figure it out.
Thank you
73
Tom KB2TDH
Tom, it’s ctrl-alt-t to open the terminal, not ctrl-alt-delete.
Or just use the switcher app as described.
Is there a way to see which backend server is being used on HamClock at any time?
Hi George,
Not from within HamClock but if you install the tools I’ve just posted (https://qso365.co.uk/2024/05/how-to-set-up-a-hamclock-for-your-shack/#backend) using this command in a terminal:
curl -fsSL https://qsl.net/g6nhu/tools | sudo bash
You can then use the command ‘what’ to see which backend you’re connected to. This works on a Quadra as well as a Pi.
73 Keith.