Homebrewing

I made and tested a couple of capacity hats for my loaded whip antenna to see how they'd do in the real world. Could you use one instead of paying Elecraft for their 40m coil? Maybe. Could you get on 30m and 40m with your KH1 whip? Might be a stretch... https://youtu.be/uYH9yit8jEo

You can follow https://lemmy.radio/communities directly from Mastodon.
Just search, in Mastodon, the url of the community, and subscribe.
Here some communities :
@amateur_radio
@digitalmodes
@pota
@sota
@dmr
@ragchew
@vhf
@cw_talk
@homebrew
...

I've been apprehensive about building my own yagi antennas before. It seemed so complicated. But then I started tinkering with antenna modelling software and decided it couldn't be that difficult. So I started building.

Life was so much easier when I realised that with a gamma match I did not have to split or isolate the elements from the boom.

On the pic is my 6m5el and my 2m5el yagis. 6m is a lot of fun this summer. There's a 10m/20m moxon spider beam coming up next.

I recently built myself a ground plane ADSB antenna. Following the results of an online calculator got me in the ballpark of the lowest SWR being close to my target frequency. At this point, I started adjusting things and noticed that the SWR shifted when I adjusted the vertical angle of the radials. SWR shifted to my chosen frequency when the radials were about 20* above the horizon, which looks like no ground plane antenna I've ever seen before, which either have horizontal or radials angled down at 45*.

With that background, I have 3 questions: 1: What is the implication on radiation/reception pattern of ground plane radials above horizontal? Am I missing out on transmissions close to the horizon and adding vertical gain?

2: Does SWR being lowest with "inverted" radials indicate that the radials are too long? Too short? Just right and I did something else wrong?

3: Is ground plane radial length measured from the attachment point, or the theoretical distance between the end of the radial and the bottom of the radiator? There's a good chance I built these too long, since I measured the radial length from the attachment point, not the base of the radiator (~1cm further)

Thanks for any guidance! Antennas are black magic to me, and I clearly don't know the right terms to put into search engines to find the results to these questions.

Diz W8DIZ has retired from running kitsandparts.com, and KU4QO had taken over.

Good news if you need toroids and other small parts. And the 5watter is a great radio if you need a kit.

An interesting proposal about how to improve APRS data transmission over LoRa: https://aprs434.github.io/

Ricardo CD2RXU is developing firmware https://twitter.com/richonguzman/status/1671034373230010369

Original project was from Austrian amateurs: https://www.lora-aprs.info/

End-fed half wave (EFHW) is a simple to build and easy to deploy multi-band antenna, very convenient for field stations. It is a perfect antenna for field day-type stations, and for quick and simple setups, like during POTA activations. Leon, NT8B explains how the antenna works, how to build one, and how to use it.

I was inspired to copy W1GHZ's power meter from April QST (pg 52). Seemed like it would be nice to know if my 10GHz rig (or any of them!) was putting out power. Got some bargraph boards from him, the rest of the parts from the internet, and finally built it today.

I had a bit of trouble cutting a square hole with only a hand drill, but I can see the bars. (If anyone likes designing and printing cases, let me know!)

Turns out I don't have any 9v batteries, so testing will have to wait until I go to the store. I don't expect to have any problems though, since the bargraph circuit is pretty simple, and the AD8317 board had everyone on it already.

Anyone working on anything fun or interesting?

For some reason (probably price!) the pixie is considered a good beginners kit. I would disagree. It is small and simple to the point of being practically useless. Get a Forty 9er instead. For a few bucks more you will have a decent radio when you're done.

But since it is popular, I made a few videos trying to explain how it works: https://www.youtube.com/playlist?list=PLxpKweJs4V-1uTGK2TqhsQXCAd6eJtPhp

I think the way the designer was able to use a single transistor as both a mixer and power amplifier is pretty clever. Maybe some day I'll think of something that neat :D