Justin K5EM's Avatar

Justin K5EM

@k5em.com

Tech, ham radio, hacking, weather. Enjoy SDR, antennas, contesting, satcom. HW/FW/SW engineer mapping with drones. He/him. http://satmatch.com also @k5em@mastodon.radio

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06.02.2024
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Latest posts by Justin K5EM @k5em.com

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Happy to announce I won the European Open Source Academy Special Recognition for Skills and Education! @eosa.bsky.social

www.zerotoasiccourse.com/post/eosa_aw...

07.03.2026 19:48 ๐Ÿ‘ 25 ๐Ÿ” 3 ๐Ÿ’ฌ 4 ๐Ÿ“Œ 0

This is awesome Matt, bravo! Well deserved.

08.03.2026 04:31 ๐Ÿ‘ 1 ๐Ÿ” 0 ๐Ÿ’ฌ 0 ๐Ÿ“Œ 0

It works really well. We did the 85ft one on Palau, a bit hard to put up, really need 5-6 people. The shorter ones are much more manageable, but many hands make it easier still.

20.01.2026 05:47 ๐Ÿ‘ 2 ๐Ÿ” 0 ๐Ÿ’ฌ 1 ๐Ÿ“Œ 0
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PATCH โ€” Futile Programmable Audio Topology & Control Hub: build modular synth patches in your browser.

made a new thing. I wanted to play around with the web midi api and this seemed like a fun way to do it www.futile.com/patch

#music #PatchSynth #ModularSynth #WebAudio #VirtualAnalog #SynthDesign

11.01.2026 00:21 ๐Ÿ‘ 5 ๐Ÿ” 1 ๐Ÿ’ฌ 0 ๐Ÿ“Œ 0

And we had an early case of a couple of logs going missing as well. Fortunately we have some cross checking that caught it, but it's a challenging job. Thank your contest organizers and give them grace, I'm sure they're doing their best with what they have, and they're all volunteers.

06.12.2025 18:22 ๐Ÿ‘ 1 ๐Ÿ” 0 ๐Ÿ’ฌ 1 ๐Ÿ“Œ 0

As a contest organizer, this is my recurring nightmare. A lot of times we're working with legacy software and systems outside our direct control. I've rewritten log checking SW for Salmon Run this year, and we've done our best to cross check the results by hand, but we can't hand check everything.

06.12.2025 18:20 ๐Ÿ‘ 1 ๐Ÿ” 0 ๐Ÿ’ฌ 1 ๐Ÿ“Œ 0
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TinyGPU v2.0. A standalone GPU that can display a model file from Flash.Render 1K tri at 6.5fps in 320x240, 4-bit color. Tested on Basys3 FPGA. Submitted to the upcoming #TinyTapeout shuttle.
more spec ๐Ÿงต.
git:
github.com/pongsagon/tt...

03.11.2025 06:15 ๐Ÿ‘ 9 ๐Ÿ” 3 ๐Ÿ’ฌ 1 ๐Ÿ“Œ 0
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#Hackaday #Supercon through the lens of my Googly Eye Camera

09.11.2025 17:27 ๐Ÿ‘ 9 ๐Ÿ” 2 ๐Ÿ’ฌ 1 ๐Ÿ“Œ 0

Fun morning knocking out a Pasadena area favorite SOTA summit with John before the last day of SuperCon

05.11.2025 04:35 ๐Ÿ‘ 9 ๐Ÿ” 0 ๐Ÿ’ฌ 0 ๐Ÿ“Œ 0
Justin K5EM -  Building Community through Radiosport | Sofas on the Air Ep. 8
Justin K5EM - Building Community through Radiosport | Sofas on the Air Ep. 8 YouTube video by SOTA+

I was in Los Angeles this weekend for @hackaday-feed.bsky.social SuperCon and had the chance to meet up with some of my favorite SoCal SOTA peeps @n6ara.bsky.social and Mark KD7DTS and chat on the sofa. Don't miss the earlier episodes!
youtu.be/VBG_cy7qeCM

04.11.2025 19:47 ๐Ÿ‘ 1 ๐Ÿ” 0 ๐Ÿ’ฌ 0 ๐Ÿ“Œ 1

LOS it would have been fine unless the repeater is unusually deaf. I have hit LA area repeaters from the 10kft ridge north of Telescope Peak in Death Valley NP with my HT no problem (250km). Easy to get into Vegas area repeaters from there too (175km). See also: working the ISS with HTs.

24.10.2025 04:18 ๐Ÿ‘ 0 ๐Ÿ” 0 ๐Ÿ’ฌ 0 ๐Ÿ“Œ 0
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Great blue heron

#birds

12.10.2025 16:43 ๐Ÿ‘ 11 ๐Ÿ” 2 ๐Ÿ’ฌ 0 ๐Ÿ“Œ 0

Another @mightyohm.bsky.social kit in the wild

27.09.2025 20:42 ๐Ÿ‘ 4 ๐Ÿ” 1 ๐Ÿ’ฌ 0 ๐Ÿ“Œ 0
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The Folded Monopole | James Sawle (MD0MDI) The Folded Monopole antenna has been around for several dozen years, but is not well known in the amateur circles. The Military has had this one in various

Looks like a VHFish version of a folded terminated monopole. www.md0mdi.im/the-folded-m...

28.06.2025 20:22 ๐Ÿ‘ 0 ๐Ÿ” 0 ๐Ÿ’ฌ 0 ๐Ÿ“Œ 0

I have a pretty similar looking interferer at the same frequency that comes on every night at sunset. It's a neighbor's garden LED light strand. They turned it off for me for a while but it's back recently so I guess they didn't replace it.

14.06.2025 00:51 ๐Ÿ‘ 0 ๐Ÿ” 0 ๐Ÿ’ฌ 1 ๐Ÿ“Œ 0
Aurora Borealis timelapse, 3 June 2025, Seattle WA
Aurora Borealis timelapse, 3 June 2025, Seattle WA YouTube video by Brent Bradbury

youtu.be/uo8aUfx5FfI?... 4k!

08.06.2025 19:44 ๐Ÿ‘ 0 ๐Ÿ” 1 ๐Ÿ’ฌ 0 ๐Ÿ“Œ 0
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What an inaugural post on bsky.app. A (the) major glacier collapse at Bichgletscher/Kleines Nesthorn.

28.05.2025 13:43 ๐Ÿ‘ 194 ๐Ÿ” 72 ๐Ÿ’ฌ 10 ๐Ÿ“Œ 10
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Never seen before perspective of a tornado in Arnett, OK by our research drone on May 18th. Watch the full video here on YouTube: youtu.be/NGD2e741Riw

20.05.2025 15:23 ๐Ÿ‘ 114 ๐Ÿ” 40 ๐Ÿ’ฌ 3 ๐Ÿ“Œ 11
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Day 2 of Hamvention 2025! Stop by Booth 5004! #hamradio

17.05.2025 13:21 ๐Ÿ‘ 7 ๐Ÿ” 1 ๐Ÿ’ฌ 0 ๐Ÿ“Œ 0
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All Merit Badges A-Z Merit Badges A-Z Merit BadgesA-Z The requirements posted here are the most current, accurate, and official. This will always be the best place to find the most up-to-date requirements.

So glad they're finally publishing these digitally, it'll be a big help for us that are MBC!

www.scouting.org/skills/merit...

13.05.2025 14:59 ๐Ÿ‘ 0 ๐Ÿ” 0 ๐Ÿ’ฌ 0 ๐Ÿ“Œ 0

Really have to wonder whose side the issue is on with Apple now a direct competitor. I've also been a long time user on Win and I've found it getting more stable and consistent of late (though there are occasional hiccups)

09.05.2025 03:55 ๐Ÿ‘ 1 ๐Ÿ” 0 ๐Ÿ’ฌ 1 ๐Ÿ“Œ 0

That's a useful rule for release, but I was talking about the next section, which recommends 50-70% coverage for the EP and references the next figure with a 66% by printed area comment. The example EP land is 6mm^2, with 4mm^2 of paste. All of this is dependent on the stencil thickness of course.

28.04.2025 02:22 ๐Ÿ‘ 0 ๐Ÿ” 0 ๐Ÿ’ฌ 2 ๐Ÿ“Œ 0

Where did you land at? I tend to follow the 66% coverage by area that TI recommends in their QFN guide, but I've found it's sometimes still a bit much for heavier parts.

27.04.2025 22:55 ๐Ÿ‘ 0 ๐Ÿ” 0 ๐Ÿ’ฌ 2 ๐Ÿ“Œ 0

This is super interesting, did they mention the primary use case?

08.04.2025 06:20 ๐Ÿ‘ 2 ๐Ÿ” 0 ๐Ÿ’ฌ 1 ๐Ÿ“Œ 0

Haha! This sunspot migration thing was a cool fact presented by @tamithaskov.bsky.social when she spoke at the WWDXC convention in 2019. I'm probably not recalling it perfectly, but that was a great talk!

03.04.2025 04:48 ๐Ÿ‘ 2 ๐Ÿ” 0 ๐Ÿ’ฌ 0 ๐Ÿ“Œ 0

Sunspot numbers are one way to measure it. The other is the band of sunspots have reached the suns equator in the south and are almost there in the north. The sunspot complexes tend to migrate from the poles to the equator over the cycle and then die out, restarting again at the poles

03.04.2025 04:42 ๐Ÿ‘ 2 ๐Ÿ” 0 ๐Ÿ’ฌ 1 ๐Ÿ“Œ 0

Vertically polarized Yagi usually points towards CB. Appears that there's an 11m vertical on the back patio leaning the other way too. The Amateur Radio license map also doesn't have any hams with a license address in Strong, you have to go to the next town over to find a ham.

02.04.2025 05:50 ๐Ÿ‘ 0 ๐Ÿ” 0 ๐Ÿ’ฌ 0 ๐Ÿ“Œ 0

Yes, more overlap on 40m would be ๐Ÿ‘. We chased DX on 40 anyway, but it was one station on top of another across the whole shared 75kHz. I was op both nights when 40 was open to EU and wasn't able to run with 1.5kW and 3el at 1ฮป. Ran JAs no prob. Lack of DX on 20 hurt. 10% lower score than last year

31.03.2025 18:00 ๐Ÿ‘ 0 ๐Ÿ” 0 ๐Ÿ’ฌ 0 ๐Ÿ“Œ 0
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Got it! Walk up to them, give them a pet, check their teeth and tail, then whack them over the head. We grew up with these "river rats" water skiing on the Brazos. They could be surprisingly aggressive if you happened to fall too near their nests. They'd even jump into the water and swim after you.

31.03.2025 17:09 ๐Ÿ‘ 1 ๐Ÿ” 0 ๐Ÿ’ฌ 0 ๐Ÿ“Œ 0
KZ1W claimed score chart for CQWW WPX contest. Shows the most points on 21, 7, and 28 MHz. Overall 2463 QSOS for 6049 QSO points and 977 Prefixes for a claimed score of 5,909,873.

KZ1W claimed score chart for CQWW WPX contest. Shows the most points on 21, 7, and 28 MHz. Overall 2463 QSOS for 6049 QSO points and 977 Prefixes for a claimed score of 5,909,873.

10 barely showed for us at KZ1W. A few loud EU stations our Sun morning, enough to pick off some extra mults, but never enough to get a run going. 15 and 40 were overcrowded. We had the benefit of a good supply of JAs on 15 for a few hours after each sunset. 20 was noisy, had to point JA to hear EU.

31.03.2025 16:53 ๐Ÿ‘ 2 ๐Ÿ” 0 ๐Ÿ’ฌ 1 ๐Ÿ“Œ 0