💾 Archived View for gemini.rawles.net › blog › 2021 › 06 › 27 captured on 2021-12-05 at 23:47:19. Gemini links have been rewritten to link to archived content
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(updated 2021-06-27)
Well, that's the caffeine kicked. Aches and fatigue were common at the beginning of the week, but sleep became deeper and less interrupted. By the end of the week I was asleep minutes after going to bed and slept through until morning most nights. This has made quite a difference.
Over the weekend I spent time with a couple of good friends in a sparsely-populated corner of Staffordshire. Highlights were the Bosh chilli⁽ᵃ⁾, a huge box of sanshis⁽ᵇ⁾ eaten with Secret Aardvark⁽ᶜ⁾ sauce, trail runs to nowhere, hikes on the Ercall⁽ᵈ⁾ and the Wrekin⁽ᵉ⁾, and long-missed Indian food at Dosa Hut⁽ᶠ⁾ (note to self: try rasam⁽ᵍ⁾ with tamarind next time). But mostly just lots of long, relaxed and uninterrupted conversation, spending a day and a half with no plan or goal other than to be together.
(b) toastetc.blogspot.com — via https
(c) secretaardvark.com — via https
(d) shropshirewildlifetrust.org.uk — via https
(e) explorethewrekin.co.uk — via https
(g) en.wikibooks.org — via https
We checked the trail cams just the once this week, and with the results, Dan made Tuesday's video⁽ᵃ⁾.
In this video are some amazing fawn close-ups as well as clear video of a group of badgers snuffling around in the middle of the night and running around from place to to place. There are the usual variety of bird life, squirrels, and lots of rabbits. You can also see we've had a lot of rain, some of which has ended up on the lens. You can see the animals' coats are wet and the fox has a good shake at one point to get it off.
We were also discussing how we get great results in terms of wildlife shots from the Campark T20⁽ᵃ⁾ (the one pointing downstream), but, among all its other technical faults, the video files it saves are huge compared to other cameras for the same resolution. The result is that the cards fill up fast and the batteries⁽ᵇ⁾ run down quickly. We're hoping to replace it with another camera like the Victure⁽ᶜ⁾ so we need only check it once a week.
A new toy has come. It's the most recent antenna analyser in the cost-effective NanoVNA family. Up until now I've been measuring SWR⁽ᵃ⁾ using a second-hand MFJ 945E⁽ᵇ⁾ mobile tuner, but ever since seeing Kipz⁽ᶜ⁾ demonstrate his NanoVNA on a radio zoom night, I've wanted to upgrade to something that can show me a quick, intuitive plot over a range of frequencies. I was tempted by the ultra-portable RigExpert Stick Pro⁽ᵈ⁾, but it's far too expensive right now, even second-hand. The NanoVNA v2 Plus4 was about £130, delivery included.
(a) en.wikipedia.org — via https
The first surprise was that the unit came in a few days, all the way from Wuxi in China. It was well-wrapped. Inside the box was a rugged looking metal box with two female SMA connectors protruding. Along with it were a calibration set, consisting of pieces (open, short, load, & 'thru') to put on the connectors so that the unit could calibrate. This took a couple of minutes and I was ready to go. There was no battery, perhaps understandably given the shipping method and distance, but fitting one is as easy as unscrewing the case and inserting a standard flat-top 18650 battery⁽ᵃ⁾, available for about a fiver from your friendly neighbourhood vape shop.
You can actually use this device for a lot of things. For some examples, have a look at NC4BR's manual⁽ᵃ⁾ that he wrote for the device, as well as all the demonstration videos that are available on YouTube. My requirements were rather more simple. I just wanted to plug an antenna into the thing, run a sweep over a frequency range, and see what the SWR was like over the band that I'd cut the antenna for. That way I can make adjustments and avoid the need to tune the antenna. Well, maybe the only other thing I'd want to see now is something I've seen on Kipz's antenna analyser, the ability to test a feeder or interconnection cable for loss. Just to have that confidence that the signal's not being lost before it reaches my radio.
Well, after trying it on all the rubber duck VHF and UHF antennas in my house, I went outside and hooked up the sheep-nibbled 20m antenna and about 15m of coax, and plugged it into the new toy. A sweep from 13MHz to 16MHz revealed a lovely smooth, 201-point, approximately parabolic SWR plot with a minimum of 1.02. Admittedly, it was about 200kHz higher that the top of the 20m band⁽ᵃ⁾, but the SWR on the actual band wasn't too shabby. I operated for the rest of the evening without any ATU⁽ᵇ⁾. The 20m JS8Call⁽ᶜ⁾ frequency is usually fairly quiet, so I had a quick chat with Julian OH8STN⁽ᵈ⁾ and sat back and watched the station sending and receiving heartbeats for a bit. A while later, I got a response from Jose LU8ER⁽ᵉ⁾. I didn't recognise the prefix LU but I now know that this is in Argentina! Jose and I had a nice chat with only the occasional need to repeat ourselves. I'd like to say this was down to my excellent antenna building and diagnosis, but Sam M0SKF⁽ᶠ⁾ reported that he'd had some contacts with amateurs in Uruguay and Argentina too, so maybe that's the way the sky is right now, or something. Anyway, kinda cool to get a chat going over a 11,000km distance. Sam M0SKF commented that greyline propagation⁽ᵍ⁾ — the line on the globe that separates day and night — to that part of the word was particularly good at that particular time. Even though we were at a relatively high frequency (14.078MHz⁽ʰ⁾), maybe our signals were heading up and down this propagation path.
(b) en.wikipedia.org — via https
(g) electronics-notes.com — via https
(h) kiwi.farnham-sdr.com — via http
There's a lot more to explore with this device, though for now getting the impedance of the feedline and the antenna matched myself rather than using a tuner for it feels like a much better approach to getting my signal out.
Redrick Stevens⁽ᵃ⁾; the cinematic melancholia of Portishead⁽ᵇ⁾'s /Dummy/ (1994)⁽ᶜ⁾ and /Portishead/ (1997)⁽ᵈ⁾; Shanti Celeste⁽ᵉ⁾ and Donna Leeke⁽ᶠ⁾ on NTS Radio⁽ᵍ⁾; changing my landline's number because of several people independently remarking that it has 'too many threes' (note that both old and new will continue to work and end up at the same place); `#swhack`⁽ʰ⁾; Hambleton Brewery's Point 5⁽ⁱ⁾ beer.
(a) redrickstevens.com — via https
(b) portishead.co.uk — via https
(c) en.wikipedia.org — via https
(d) en.wikipedia.org — via https
(i) hambletonbrewery.co.uk — via https
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