Seriously, y’all: post your fuckups! May everyones’ mirror neurons feast upon tales our resilience.

My go: I’ve been trying to make a Yagi for Meshtastic because stock antenna, house construction, and geography.

I started with a W6NBC Yagi, but burnt hours trying to make a hairpin match work. The antenna was always better for 1050Hz than 915Hz.

It was only while griping later I realised I forgot to measure and tune the half-wave dipole before I added the reflector and directors. #HamRadio

Pulling on some threads, I think it's worth trying the Zhejiang Deli Connector Co. Ltd. (ZJDLL) DL20005 HY Series. Here's one data sheet I found: https://web.archive.org/web/20240818062529/https://www.zjdll.com/upload/20211016155104343225.pdf

Anyone able to find an HY connector matching the keyless version on the M5Stack modules?

Winding half a dozen inductors or more? Measure one of each type across the range of turn counts so you can correct the instructions.

Worked example for the RFBitBanger batch 2 T50-6 toroids, 40m band L2:

• find 12 on the X axis
• read up to the predicted line
• read across to the measured line
• read down to 9 on the Y axis

You might end up needing 8 turns, or 10, but either way 9 is going to waste less of your time than 12. #HamRadio #RFBitBanger #truSDX

I’ve been frustrated by brittle rules of thumb for antenna design which assure us “all” our power is lost if we use:

• an unun or a tuner
• wire of non-resonant length
• wire shorter than 0.25λ

Tim’s first three episodes show how antennas benefit from high radiation resistance and suffer from ground loss, and how their length controls their impedance and radiation pattern.

In the last, Tim rolls it all up into one table, and every cell breaks at least two of the “rules” above. #HamRadio

“Eggbeater” antennas are great for picking up satellites because of their radiation pattern and polarisation. They're tricky to get right, because the two elements must be 90º out of phase.

@smitty has solved the tricky part! You can buy his EggNOGS kit and get the phases right with low effort. https://electronics.halibut.com/product/eggnogs/

436.5MHz is in stock, and suitable for more than half of the amateur satellites transmitters tracked by SatNOGS. See charts, attached. #HamRadio #SatNOGS #EggNOGS