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Linux Kernel security developer, working for Microsoft. Also W7TXT. Views are my own.
Topics: #Linux #kernel #security, #amateurradio, #RF, #hamradio, #electronics, #science, #radioastronomy, #physics, #space, #arduino.

📡 https://w7txt.net/
🐧 https://blog.namei.org/
☠️ https://www.facebook.com/w7txt
jmorris

James Morris

Slow but sure progress on my 1kW HF/VHF amplifier power supply. Bought a PCB for the Eltek module and decided to solder the output wires (10 AWG THHN) rather than use the more common XT-60 connectors. After some research, I found out that XT-60s, commonly used for drones & RC batteries, are only rated at 30A continuous. The 60A figure is for peak current, and the available specs are very light on details generally. This PSU is being built for 40A continuous (at 50v), so the XT-60 is not sufficient. Next up will be to connect this Sparkfun CAN shield to configure & monitor the Eltek.
#hamradio #amateurradio #electronics
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jmorris

James Morris

Reply to @jmorris
And here is the power supply. 50 VDC @ 40A max. I’m using a surplus Flatpack2 server PSU, with space for a 2nd to run in parallel or backup. Also room for 28V (for relays) & 13.8V modules.
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jmorris

James Morris

Next project: assemble these components from W6PQL into an MF/HF/6m amplifier. It’s specified for 1kW but I suspect it can do more. #amateurradio #hamradio
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jmorris

James Morris

I’ve learned just enough #gnuradio to be dangerous. Now monitoring WSPR on two sub-bands of #8m as well as FT8 via an #rtl-sdr. Now if the sun could eject some coronal mass in this direction, that would be super. #hamradio #amateurradio #vhf #wspr
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jmorris

James Morris

Testing a 2-wire fan dipole on HF, doing some ALE. It’s always fascinating to see physics & information theory working per the math. Anyone else?
#amateurradio #hflink #ale #hf #antenna #rf #hamradio #radio
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jmorris

James Morris

Reply to @jmorris
Edited 1 year ago
Also, a very good signal here from VA2CY up on Île d'Orléans QC, with apparent doppler shift due to the movement of Sporadic E clouds between our stations. If you look closely at the top, there's a very weak trace from another station with some aircraft scatter (no decode). I think that is WM2XCW in Point Roberts,BC near the Canada/US border. ETA: confirmed this is not doppler shift, it's transmitter drift.
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jmorris

James Morris

I've been monitoring the 8m band recently (yes, 8m!). It's generally an ISM band with some experimental licenses issued in the US, Canada, and other countries, as well as a few amateur allocations in Europe. Some great propagation happening today between Australia/NZ and USA/Canada, on 40.68 MHz.

#hamradio #amateurradio #wspr #8m #40MHz #vhf #radio
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jmorris

James Morris

Edited 1 year ago
On a whim I tuned to the 630m band in WSPR, and was surprised to see a couple of stations. I had no idea my system could receive anything on 474 kHz. I think the signal around 1840 Hz baseband is QRSS.

The antenna is just a 100ft dipole fed with ladder line via a 4:1 balun and tuner. I believe the tuner was set for 80m.

#amateurradio #wspr #wsjtx #hamradio #radio #mf
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jmorris

James Morris

Clippy lives on 🤷🏼‍♂️
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jmorris

James Morris

This is the Xgecu T48 universal programmer, arrived with a Lunar New Year gift. The T48 supports over 32000 chips, including a bunch that of older MCUs such as the PIC16C*

#electronics
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jmorris

James Morris

Friday night fun -- learned how to use BitMagic & Tigard devices with PulseView software to make a logic analyzer. It works!
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jmorris

James Morris

Kind of wild how you can just walk up to the MI5 HQ in London.
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jmorris

James Morris

A couple of pages from Alan Turing’s 1940 treatise on the Enigma machine. Is there a important piece of reverse engineering?
@ Bletchley Park.
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