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Table of Contents
Dave's Thoughts
ARRL FMT setup
(edited after 2025-04-17 fmt)
The ARRL runs a neato contest twice a year - the Frequency Measuring Test (FMT). The objective is to measure a transmission's unknown frequency as accurately as possible. There are 4 transmissions: 2 different geographical locations on 2 different bands (40m and 80m). The tests are run in the evening when the ionosphere is changing which adds an unpredictable element (doppler shift) to the results. Like any good “contest”, it's part skill and part luck!
The results are reported in accuracy windows:
- <= 1 Hz
- > 1 Hz to <= 5 Hz
- > 5 Hz to <= 10 Hz
Greater than 10 Hz doesn't get reported in a window but does get reported in your results listed by callsign.
You'll notice there's a method/soapbox with each callsign. If the contestant chooses, they can report their setup. Some of the setups consist of some amazing gear. My setup is basically my radio station with the addition of a GPS disciplined oscillator, namely the leo bodnar.
Here I'll note how I did my measurements so I can remember for future contests. I'll update this as I learn new things.
Etymology in Today's World
When people send LOL, did they really laugh out loud? What if I really laughed out loud? Should I send LLOL: Laughed Literally Out Loud.
But wait, did I mean literally literally or did I mean literally figuratively?
LLLOL.
44net: amprd IPIP on Fedora 40
(EDIT: correct recommended subnet mask for 44. Of course it's no longer /8. It should be within either 44.0.0.0/9 or 44.128.0.0/10.)
The amprd package installs directly from the fedora repository. The configuration is straightforward, however getting firewalld and NetworkManager configured is a little tricky.
The amprd documentation refers to requiring the ipip_redirector for 4.13+ kernels. It's not required for the 6.8.9 kernel that comes with Fedora 40.
Note for the most part the commands require root so put sudo in front of the commands or become root with 'sudo -i'
Fedora release upgrade without an RTC
I'm running Fedora on my Raspberry Pi 4b. I recently tried to upgrade the release from Fedora 38 to Fedora 39 Beta. After the system-upgrade reboot, I got pages of errors about certificates not yet being valid. I realized that my system clock was set about 10 days in the past, September 17th to be exact.
Since the upgrade reboot doesn't come up with a network connection, ntp doesn't set the time. But the time isn't January 1, 1970. So where was this 10-day-old time coming from?