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Dave's Thoughts and Ideas

PiJuice Hat support on Fedora

PiJuice Hat code is close to being able to run on Fedora. With some small modifications it is available as a Fedora Copr RPM.

The current fork can be found here. Instructions for installing from Copr are here.

2023/10/24 05:00 · davek · 0 Comments · 0 Linkbacks

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?

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2023/09/30 18:44 · davek · 0 Comments

FFT scaling factor

What's often confusing about the FFT is that the transform seems to have numbers that are too big. Let's call this the “FFT scale factor” problem (it's a reasonable google search). The frequency domain seems to have much more energy (much higher values) than one might expect from the time-domain waveform from which it originated.

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2023/09/30 21:39 · 0 Linkbacks

Maritime Mobile in VP2V

I just got back from a glorious trip to the British Virgin Islands (VP2V/N9DK/MM). Friends and I sailed among the islands: Norman, Cooper, Virgin Gorda, Anagata, Tortola, Mosquito.

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2022/07/10 22:06 · davek · 0 Linkbacks

Single letter TLD

When running a private network with DNS the network admin will set up .localdomain or .local as TLD for the private network.

But that's so many letters! Single letter TLDs are not assigned to anyone. While I'm pretty sure that's not an official rule, it would seem that they are specifically excluded. See the current list.

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2021/11/11 23:15 · davek · 0 Linkbacks

Setting up dokuwiki

I've been a fan of dokuwiki for years and years, going back to my startup in 2005 when I used it to document our designs, usage, actions, etc. It's similar to the popular Mediawiki but offers better ACL. I've set it up multiple times in multiple ways, always a little concerned about security. I've had installed plugins with security flaws and it's just hard to stay on top. Most of the time I've deployed it for internal use inside a firewall.

Having worked at a startup for over 2 years that's heavily invested in docker, I've gotten to know docker really well. Not having had a website for quite a while, I finally decided to dip my toe in the water again using docker to contain my dokuwiki site.

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2023/09/30 21:39 · 0 Linkbacks

10 questions about your QRP operations

QRP Quarterly has a column asking 10 questions of QRP operators. I offered mine for the April 2019 issue. I don't think there's any issue with publishing it here in advance:

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2019/03/07 05:23 · davek · 0 Linkbacks
start.txt · Last modified: 2022/10/20 17:27 by davek