HamClock
16 views
Skip to first unread message
Howard Zehr
Dec 16, 2025, 8:56:58 PM12/16/25
to Valley Valley Hams Hams
If anyone is interested in trying Hamclock for propagation prediction and analysis, I’ve put instructions for installing it on Raspberry Pi on my blog, website below.
Randy
Dec 17, 2025, 2:40:34 PM12/17/25
to Howard Zehr, valleyhams
Thanks for sharing Howard. I have one of those in the shack too.
Mine was built around a Pi-3b, installed in the Pi case with the 7" display. Here's a short video to show it, rotated from front to back.
The board on the rear contains a GPS receiver for time synchronization. The Pi is running a version of NTP and serves as a stratum-1 time server for all of the computers on the local network.
I thought too, that it might be nice to have a 10 MHz reference clock for any piece of test equipment or radio gear that had a provision to utilize it. There's a 10 MHz TCVCXO on the board that is disciplined from the GPS reference and controlled by a daemon running on the Pi. There's a provision for an AVR 8-bit micro on the board too, just in case I wasn't able to get the Pi to control it properly. The shortcoming in all of that, I neglected to put a shield over the TCVCXO on the board and moving air from the HVAC system in the house has quite a negative effect on frequency stability. Oh well, it's still a nice time standard. :)
Here's a short video showing the rear board in more detail with an LED flashing when the GPS 1-PPS signal arrives. The board just plugs into the header on the Pi and is held in place by friction.
As you can see in the video above, the board also has a fan for additional cooling of the Pi. The Pi has the heat sink installed on the micro and passive cooling is supposed to be sufficient on the 3 series but these run hot to the touch and, since there's a PCB right there with room, why not add a fan.
Here's an image of the GPS board in the cad system.
Get one running before Christmas and you might catch Santa as he passes over.
If you don't want to use a Pi or a have a dedicated linux box, you can install it on windows under WSL.
I've really enjoyed having one of these. I almost never sit down at the radio table without glancing up to see what's on the propagation map.
I have a callbook server running on the Pi too and that's handy for a quick call look up or, in the case of field day when I'm just trying to work all 50 states, I can pipe the output from cwskimmer through a script that will send the callsign, frequency info, and state information to a terminal window. That's way faster than looking up the callsigns manually to find needed states.
When this one dies, I'll replace it with something having a larger screen. Some of the text is not the easiest to read on the 7" display. The downside with that, the software only supports a 5:3 aspect ratio and those displays aren't as readily available or inexpensive as a computer monitor or TV. There will be some wasted area.
Here's a link to the Hamclock author's page, Elwood Downey, WB0EW.
Randy
--
--
You received this message because you are subscribed to the Google
Groups "ValleyHams" group.
To post to this group, send email to valle...@googlegroups.com
To unsubscribe from this group, send email to
valleyhams+...@googlegroups.com
For more options, visit this group at
http://groups.google.com/group/valleyhams?hl=en
Please do not send jokes and junk e-mail on this list - Let's use it for our various hobbies, public service, communications and any good useful information for our hobbies and Events.
---
You received this message because you are subscribed to the Google Groups "Valley Hams" group.
To unsubscribe from this group and stop receiving emails from it, send an email to valleyhams+...@googlegroups.com.
To view this discussion visit https://groups.google.com/d/msgid/valleyhams/2DAA2EE4-48AF-44FF-B170-DEC0A4AA5617%40gmail.com.
Randy
Dec 24, 2025, 6:10:37 AM (14 days ago) 12/24/25
to Howard Zehr, valleyhams
Here's Santa...
Reply all
Reply to author
Forward
0 new messages