Chopped the top off the dead transistor from my PSU. There’s nothing obviously burned in there but the left hand wire isn’t connected to the die. It’s pretty though!

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The RSGB has published #amateurradio band plans for 2019, at https://rsgb.org/main/operating/band-plans/display/

It’s a shame the interactive versions still require flash, but there are plenty of other formats.

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Interesting idea: Using a bike rim as a mag loop antenna https://www.dk9jc.de/blog/equipment/171-mag-loop-magnetic-loop-diy-with-trashed-26-inch-bicycle-rim

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Had a lot of fun climbing Toubkal in Morocco last week, but didn’t take a #amateurradio as getting licensing sorted looked complicated and I was worried about customs (also I don’t speak Arabic or French)!

The altitude made it hard work, but it was totally worth it.

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Managed to repair my PSU by replacing the faulty pass transistor, and all the others for good measure.

Now added “research overvoltage protection circuits” to my never ending todo list! Looks like there are plenty of options.

Super happy the repair worked and there doesn’t seem to have been anything else wrong with it. 🙌

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I had no idea the RSGB had a forum: http://forums.thersgb.org/index.php

Nothing like as busy as the unofficial RSGB Tech forum though: https://groups.io/g/RSGBTechnical

The latter has some interesting stuff in amongst all of the moaning and one-upmanship.

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Found this page on my dead PSU https://pa0fri.home.xs4all.nl/Diversen/EP925/ep925eng.htm which makes it sound like one of these beefy 2N3055 transistors has probably died.

No sign of scorch marks etc though! 🕵️‍♂️

I still think dumping the full 24 volts across the terminals is a rubbish failure mode.

Dead transistor now identified!

Attached is how my cheapo component tester said it behaves now. Basically a short from collector to emitter, and that’s how I found it (meter on continuity mode, testing across disconnected transistors).

Tempted to replace all of them as they’re not too expensive.

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My linear PSU just died. ⚡ Symptoms are 23 Volts across the terminals instead of the normal 13.8. What a terrible failure mode!

Hoping it might be easy to fix, but it doesn’t really owe me anything.

It’s one of these bog standard models ( https://www.eham.net/reviews/detail/4064) which I got from @Powyssafety last year.

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My new favourite tool is this Engineer solder sucker. The tubing on the end makes a huge difference to the amount of suction you get.

Naturally, the writing on it is only the right way up when it’s in your right hand!

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Wow, these tiny Korg valves look amazing: https://korgnutube.com/en/

I wonder how long it’ll be before someone makes a radio with them in.

https://korgnutube.com/wp/wp-content/uploads/images/omote.png

It looks like RS are selling headphone amp kits which use them https://uk.rs-online.com/web/p/analogue-development-kits/1813534/

Expensive though!

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