Radio, railways, stuff...

So this is my last blog post and this blog will be deleted in a couple of days. I simply have too many things to attend to in life than keep the information here in any way fresh or useful. There are now so many sources I am just adding to the noise. These days running a web server - I host this blog on my own hardware - consists of security patching, log monitoring and threat removal, plus a bit of actual publishing along the way. If you don't do security monitoring and patching you become part of the problem. The server does other things so I need to keep an eye on it. After some logfile analysis I can see that over a typical day the vast majority of accesses are search engine spiders, some RSS grabbers, many threats, and one or two actual humans. And there are a lot of attacks, I can spot them a mile off because having been actively running websites of all sizes since 1992 I can look over a log file and easily spot them. So there you have it. Most of my posts here are essentially for my own benefit with…

My interest in radio, and electronics more generally started when I was about 6 years old. Interest in railways came shortly after but more so was an interest in telegraphy. I suspect that came from listening to morse signals. Anyway, however it came about the telegraphy side of things coupled with my railway interest via railway signalling when I was invited into a sigal box and saw the various telegraphy kit. Fast forward a few decades and an entire unrelated career and I find myself working on a heritage railway in the - you guessed it - Signal and Telegraph department. So, and in keeping with the title of my blog here are a couple of work pictures... The lever frame. Both mechanical and electrical interlocking is used here in order to ensure conflicting routes cannot be set. The mechanical interlocking is behind the levers under cover and the electrical interlocking is under the floor. These indicators show the state of signals (on or off) and points (normal or reverse) plus 'wrong'. The instruments use DC coils so that a single wire to whatever is monitored can be used with a polarity reversal to indicate the two states. The 'wrong'…

I made some time to have a play with Meshcore on 868MHz. I had a Meshtastic node in the loft but locally the only traffic was people sending test messages so I fell out of love with it. I installed Meshcore as a USB client which allowed me to talk to it via one of the Linux boxes here and use a command-line interface but it was lacking in features. Anyway, I found another 868MHz device today and installed the Meshcore BLE companion code, and then swaped the loft node for the repeater code. After a little while it all came to life. There is a repeater about 7km from here that my loft repeater can see so my tap into the network is via that. It is much nicer using the iPhone or iPad app than struggling with the serial connection - well, no surprise there of course. As to how useful it will be, to me it still feels a tad toy like but that's probably just me.

For some time now I had been running a radiosonde receiver based on one of the small Lilygo LoRa devices with a built-in display. It used wifi to connect to our LAN and thence off to its reporting platform https://sondehub.org/. Because it used an antenna in the loft it never did very much with regard to monitoring but it was a no-cost 'why not' type of thing. However, after some time now the display was dimming and it would often have issues if the wifi hub rebooted. So I really wanted a no-wifi solution and found one based on a Pi and an RTL-SDR dongle.The software and setup instructions I followed can be found here and worked semlessly. The setup creates its own web server, by default at port 5000. After a few days of nothing it finally recorded two hits overnight: Not too bad for a 70cm Big Wheel in the loft. Looking at the data, for the first entry which is the one approaching Liverpool data was received when it was at 11,500m altitude down to 9,521m at 403.4MHz. The second trace out to sea was on 405.1MHz and from 19,670M to 25,349m at the end. The traces…

Since I got it the FTM510D has been mounted under the shelf above the monitors. While that was ok it meant the mic lead was always caught behind one of the monitors. Having tidied one bookshelf and moved things around moving the Portsdown left a space under one of the three screens. A space, I thought ideal for the FTM510D. But how to mount it neatly... A search for 3D prints for the radio resulted in mainly mobile solutions but I came across a comment on one aimed at an earlier model saying the dimensions should be the same. It seems the FTM150 has the same slidemount arrangement and dimensions. So, off to makerworld - https://makerworld.com/en/models/1181052-desktop-stand-for-ftm-150rasp-may-fit-others - and off to order more PLA because I had hardly any of any sort of black filament. Twenty eight and a bit hours later... my biggest and longest print to date. Anyway, it worked just fine. After trimming the bits the radio slots straight in. The model even has a slot to hang the mic, and it sits just right under the monitor. Four sticky feet to stop it sliding finished it off. Surprisingly all the cables were of sufficient length for the radio's…