Peter

Worn out computer scientist and academic.
Homebrewer 50 years ago such as RTTY terminal unit with valves/tubes (including a Schmitt trigger - with valves, honestly), up-conversion RX.
Bought kit now I an afraid.
UK Maritime Long Range ticket: MF/HF (SSB) and VHF - but don't sail any longer.
Walk the dog. Read the news through half closed eyes while gnashing my teeth.

2025-05-02

Lowest SWR or resonance?

(Given that a resonant 1/4 vertical has 36 ohm impedance)

Now I am a nanoVNA wrangler I can tune the elements on my DX Commander for resonance, but around 1:5 SWR; or under 1.1 SWR, but not resonant.

Which is best?

(

2025-04-27

@IU1KGS It's cursive rather than serify. But, yes, horrible.

Many years ago I wrote a font to look like it was from a manual typewriter: uneven pressure, not all exactly bottom aligned, slight traces of ribbon grain.
Never caught on

2025-04-26

@dc1tc Thanks Tobias. Reports of real world experiences like that are helpful to those of us following behind.

2025-04-26

@dc1tc Well done! Just out of interest, what was the speed of your contracts?

Asking for a friend, as they say....

2025-04-22

@OH3CUF The problem I have with Maidenhead is that I don't know where a square *is* without looking it up.

On the other hand I know that 61N 23E is around 1000 to 2000 miles NE of me, just from the lat long difference between that location and mine.

2025-04-21

@vk6flab Not a like for like comparison.

The six character grid square you give is to nearest 5km, while the lat long, with four decimal places of a degree, is to about 10 meters

See:

support.garmin.com/en-GB/?faq=

giangrandi.org/electronics/rad.

2025-04-21

<rant>
Why Maidenhead Grid Squares?

Google maps doesn't know about them.

What's wrong with plain old Lat Long.

At least you can eyeball Lat Long and get some idea where it is.
</rant>

2025-04-18

@on5zo After checking Pokémon reference with local expert. Ho ho ho.

2025-04-18

@on5zo And also like fishing, you don't expect to catch them all.

2025-04-16

@jamesb Ooh! You are awful!

2025-04-16

@dl2jml Jerome, thanks - I had seen that link. It's rather a strange article. It mentions a key advantage, low height, and then proposes doubling it!

I also don't understand the article's take on poor efficiency: it acknowledges the antenna is designed to be used with a short length of low loss feed line and goes on to blame the design when folk use a long one.

The article's sweeping generalisations about antenna characteristics that are, or are not, useful to hams is rather presumptuous.

2025-04-15

@jamesb that is a very kind offer - I am touched. There are a couple of things I need to try though: at least trying it barefoot and looking at actual SWR is first.
[Edit: changed SWL mistype to SWR]

2025-04-15

@dl2jml The US Army and Collins Radio did a lot of modelling and practical tests on a 15ft high inverted V (AS-2259/GR) and came up with 13 ohms.

A ham version will have a slightly higher impedance since it will be cut for resonance.

2025-04-15

@IU1KGS @ve3qbz @jamesb I guess I should just try it barefoot see what the SWR is like.

2025-04-15

@ve3qbz Yes. I think the confusion between 1:4 and 4:1 is widespread.

My take is the thing is called a BAL - UN and the order is important. The ratio should be expressed in same order, from BALanced to UNbalanced.

2025-04-15

I can't find for sale anywhere a 1:4 #balun for HF. It is for a low height 40m inverted V #NVIS #antenna. Military versions such as #AS-2259 use the custom coax support pole as an impedance transformer.

To be clear, I mean 12.5 ohm balanced antenna side to 50 ohm unbalanced coax side. The ones for sale on eBay/Amazon seem to be mislabeled 4:1 ones.

Making one isn't an option: my hands don't work properly.

Anyone any ideas.

Peter boosted:
2025-03-31

Picard management tip: It takes hard work to become a master at single-tasking.

Peter boosted:
2025-03-25

Perhaps the top person at The Atlantic was added to the Signal chat because those on the chat believed there was a person in charge of the Atlantic.

2025-03-25

I wonder if they respond to Signal's "please donate" messages

"The Atlantic magazine's Jeffrey Goldberg reported that he had been added to a Signal message group which apparently included Vice-President JD Vance and Defence Secretary Pete Hegseth."
[BBC News online 25 March 2025]

#signalapp

2025-03-18

@ve3qbz Jack dog has two distinct modes: indoors he is essentially a cat, seeks warmest spot, sleeps a lot, gets *in* our bed; outside he is an brave independent explorer. We leave the house at the same time and arrive back at, more or less, same time, but I hardly see him. He occasionally pops his head up from undergrowth 500m away to make sure I'm keeping up, but that's it.
We are lucky to live on the edge of extensive upland moorland - doggie heaven.

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