Radio and rails...

Up until now I have been running 3 Raspberry Pi 4 systems all held in a metal frame with fans which makes a nice neat setup. One Pi does the home automation, one runs pi-hole (really useful!), and one is a server and has an SSD attached. Not long ago while we were out of the country (of course) the website hosted by the server failed. I did not have remote ssh access set up nor a VPN for access. When we got back home the pi had lost the filesystem on the SSD. The disk was still mounted, but not accessible. Being a server all logging was on the SSD so no errors were caught. A reboot was the only way to cure it. I thought it was a one off until it happened again, this time while I was nearby. After that our broadband was upgraded to FTTP and with PlusNet giving a fixed IP and no blocks I moved my production websites and email server across to the Pi, saving the rental of the VPS I had been using up until then. The cost of the VPS covered the annual cost of the broadband so worked out…

Slightly random... I have a Cisco SPA504G VoIP phone which I acquired ages ago and connected to Hamshack Hotline back when the UK still got 5 digit numbers. The phone isn a 4-line one and subsequently I got a Hams over IP number for line 2, then an extended freedom network number on line 3. After that the phone sat for ages with only the three lines in green, waiting for a fourth. I did consider buying a VoIP service to transfer our POTS number to once we upgraded to FTTP and lost the copper line. But then, all we used the landline phone for was ignoring junk calls, only ever making calls using my mobile phone which has free minutes and SMS, or using WhatsApp. So the landline went. And still that fourth line was dark, just sitting there. Along came CNet. I have had an interest in all things telephony and telegraphy from an early age. I always wanted a small mechanical PABX - I still don't have one but I do have an eye out for a couple of old dial phones from my childhood. And that's where the interest in CNet came from. Having investigated further…

I built a thing! This is a GPSDO using a PCB and kit of parts supplied by G8CUL and a OXCO from G1OGY. It uses a Jupiter GPS module which provides the PPS signal and a 10kHz output and the completed module provides 2x 10MHz and 1x 1MHz outputs. Although there are a number of such designs this one is nice in that it also has a display and shows the current date and time as UTC. This was, I think my third SMD construction and certainly the Mose SMD devices including multi-legged chips. No issues in construction especially given the quality of the PCB that G8CUL had made. The backup battery is a CR2 3.3V type and helps with warm starting. As the regulator gets hot I managed to fit a heatsink between it and the rear of the case and hopefully this will sort out heat transfer, otherwise I may need to bolt another heatsink on the rear. Construction in a die cast box would have been better maybe but the blue/white box fits in with others in the shack, plus I had it already! The bezel is cut down from a 3D printed one from Printables.com designed…

So this is my day job - well, not exactly a job and only one day a week - volunteering at a heritage railway. And here we are in the middle of nowhere... good job it isn't raining this time.

I had a number of Molex pins to wire up recently. To make things easier I decided to use some 4-core signal cable I had but found that the insulation is so poor at resisting heat that soldering the Molex pins was a non-starter as it always ended up with bare wires. Of course, Molex pins are designed to be crimped... so off to eBay. The latest addition to my toolbox arrived in a couple of days and made the job a lot easier.