@g4dbn decent antenna setup

RE: https://mastodon.radio/users/g4dbn/statuses/111865540448497761

Finished making a thing. This is a power supply for the 30W 10 GHz amplifier I’m working on. It should also be able to power the transverter, IF radio, & relays. I’m resisting the temptation to add an MCU and display. For now.

(Note: the 50 Hz label should say 60 Hz)

#hamradio #electronics #amateurradio #microwave #qro #sspa

Not sure if this microwave power sensor is repairable. It’s an HP P486A waveguide thermistor mount for 12.4 to 18 GHz. It was bugging out, and I’ve rejuvenated one of these before (using the guidelines in the manual) but it didn’t work this time. I’m puzzled by the mechanics of this, what the adjustment screw actually does, and why is it attached to a small metal block which is maybe held with conductive paste? It’s supposed to finely match the inner and outer thermistors: one is in the waveguide and the other is inside the housing as a reference. The waveguide thermistor is heated by the RF signal, and the power meter detects this, via a bridge circuit which tries to balance the current in each thermistor.

The wonders of 1960s microwave tech. We explored space with this stuff.

#hamradio #amateurradio #microwave #electronics

Crazy read: detecting positions of players in Counterstrike by *listening to their GPU over a microphone*

https://faculty.cc.gatech.edu/~genkin/papers/lendear.pdf

Released picolibc version 1.8.6 today.
Highlights: ctype avoids a static array, fenv functions are inlined (except on x86).
Full release notes here: https://github.com/picolibc/picolibc/releases/tag/1.8.6

❕ 📢 Note: The LSS-NA 2024 CfP has been EXTENDED ❕

🐧 The new CfP deadline is: Sunday, February 4 at 11:59 PM PST

🐧 For full details, see
https://events.linuxfoundation.org/linux-security-summit-north-america/program/cfp/

RE: https://social.kernel.org/objects/a91fa775-15d9-4ee0-bc99-f9b40cad10c5

Announcing the acquisition of Evil Mad Scientist by Bantam Tools.

Dr. Windell Oskay & Lenore Edman will be joining as CTO and COO of Bantam Tools in Peekskill NY.

Pen plotter enthusiasts can look forward to a new generation of art machines in Spring 2024.

More at: https://www.evilmadscientist.com/2024/bantam-tools/

SELint, a linter for SELinux policy sources, released a new version yesterday: SELint v1.5.

https://github.com/SELinuxProject/selint

#selinux

Working on a 10 GHz power amp. #hamradio #amateurradio #electronics #microwave

Very shiny for +50years old equipment.

@LWN they grow up so fast

RE: https://fosstodon.org/users/LWN/statuses/111581306340618478

Just a warning for people thinking about getting into #microwave #amateurradio -- it's an infinite labyrinth of hobbies, knowledge, and equipment. Precision machining, stripline circuits, strange semiconductors (IMPATT diode amplifier, anyone?), exotic electron tubes (which will try and kill you via xrays, lethal voltages, and beryllium oxide), metrology, physics, DIY, vintage equipment resurrection, morse code (modulation? sheer luxury!), scouring ebay, haunting electronics stores, poring over poorly scanned service manuals from defunct companies, and too many hex keys.

Oh, and it's a gateway drug to #radioastronomy.

#hamradio

@evacide Yikes. How much information did Verizon actually need to collect or keep?

RE: https://hachyderm.io/users/evacide/statuses/111608814425154905

Making some hopefully final mods to the azimuth sensor for this az/el drive. Spent ages trying to find screws to match the Hammond enclosure. Turns out to be M3.5, which I have never seen used before. #hamradio #amateurradio #microwave #radioastrnomy

TIL my 50 MHz scope is still somewhat usable up to 150 MHz.

A new release of SETools is available:

https://github.com/SELinuxProject/setools/releases/tag/4.4.4

Changes:

* Update for compiling with libsepol 3.6.
* Update apol to use fully specified PyQt enums.
* Correct minor code lint issues.

Another reminder that you only have ONE week left to submit to the containers or kernel devrooms at FOSDEM 2024!
https://stgraber.org/2023/11/26/containers-and-kernel-devrooms-at-fosdem-2024/

A 2023 #scientist #linocut for #ArtAdventCalendar of #astronomer Vera Rubin (neé Cooper, ‘28-‘16) & her discovery that angular motion of galaxies deviates from predictions, 1st evidence for dark matter, now known as 5x as common as matter & the stuff which dictates dynamics of galaxies & evolution of our universe! The Nobel committee waited 3 years after she died to reward another for the theory of dark matter.

She found 6 months mat leave post MSc very difficult 🧵1/n

#printmaking #sciart

#EmacsConf was tons of fun! :) The prerecorded videos are up at https://emacsconf.org/2023/talks and I'll work on extracting the live talks and Q&A this month.

It ain’t much, but it’s honest work. Az/El sensors serial (SSI) to Arduino board. Removed an RS485 layer.
@adafruit 1/4 size proto boards are cute.