Radio and rails...

"Zilog has called time on the Z80 CPU." (https://www.theregister.com/2024/04/29/opinion_z80/) Wow. Actually I had no idea (through never having checked) that it was still being produced. And a fine chip it was too. I never built a system from wires up using the Z80 though. My first system, designed, built from chips and wire-wrap was an 8080 system, hand programmed to control al x-ray diffractometer. This was decades ago now but I still remember it, although I have no photos unfortunately. The system had a timer chip for a 1-second count and was interface to a Nuclear Engineering (I think it was!) counter that used nixies. But I did at least use Z80s, just they came as boards. The first was a Transom Triton computer and by then I was programming in Turbo pascal - back then this was really neat as one could have procedures full of assembler code which made interfacing easy. Later I used Gemini boards and that also gave the ability to have a graphics card. By then my interfacing to the diffractometer included a stepper motor and shaft encoder to control the arc motor. In the end there were two sets of Gemini Z80 boards, one…

I now have a Raspberry Pi set up on one of the four monitors in the shack. The original layout was two screens at the top on Linux, then bottom left on Windows and bottom right - central to where I sit on the Mac as the main screen. But that layout had two major issues... I use a program called Barrier to basically act as a KVM switch for the three systems with the Mac as server. That way the Mac mouse and keyboard controls any of the systems, although it can be awkward sometimes where Windows expects keys which Apple doesn't have. But Barrier does not understand dual monitors and so moving the mouse up from the Mac got to the Linux box fine, but moving it down from the left hand screen would not get to Windows as the program does not see it being physically there. I could live with that, except for issue two... The main issue was with the Linux screens being at the top and thus making me sit back or crank my neck upwards, not a good position. So... I got to realising that although I use both screens on the Linux…

Another new toy, a Quansheng UK-K5(8). Size-wise it's taller and heavier than the Baofeng UV5R and has a nicer display. The reason I got this, apart from the price is there is firmware available to enable a spectrum display among other things. I've loaded this version: https://github.com/egzumer/uv-k5-firmware-custom/wiki. Loading was simple enough. There have been mentions that one needs to insert the programming cable very firmly but I found that my aftermarket Baofeng USB cable went in quite easily with a click. Once I had remembered you need to turn the radio on in program mode the firmware went in via the Edge browser in just a few seconds. Other than that I have yet to use it on air and it has not yet been near a spectrum analyser so no idea how good or bad it is RF wise. There's plenty of information out there already anyway. For me, like the UV5R it's a handy little radio that won't hurt too much if lost or damaged, but it is the available firmware that seals the deal.

After having ditched Meshtastic, for now at least, I had a fiddle with two of the LoRa modules with a view to repurposing them. And there they are. The first is a LoRa APRS r/o iGate, listening on 439.9125MHz, and the second is a receiver for radiosondes listening around 400MHz. Nestled under a 70cm ground plane in the shack is, of course a good way to ensure nothing is ever received unless it is very close! However, it is destined for greater things... although at the end of the day it's just me fiddling. The LoRa APRS map is at https://lora.ham-radio-op.net/ The radiosonde one stands a better chance of actually receiving something, especially as it is currently connected to the 70cm big wheel antenna in the loft. See https://sondehub.org/ The plan is to connect these two along with the module running TinyGS to a common antenna currently in the loft. They will be connected using a Crosscountry Wireless multicoupler which is due to arrive in a day or so.

For me, and this is in no way intended to persuade people not to dabble, Meshtastic was the usual 'new shiny' that I like to fiddle with, but it was just that. A bit of radio fun for little outlay using devices I can redeploy. In our wider area it seems to have snowballed and become rather congested. While I can see the point, I have many other radio bits and bobs to play with and having yet two more antennas in the loft was rather overdoing things. I had to seriously think exactly what I had used it for and it came down to occasionally saying 'good morning', answering when people ask if anyone is receiving them, and... well, I am struggling to find anything else. Of course I stress that is what I had used it for, not taking away from what others are doing. It is a neat idea. So both nodes have been switched off.