Radio and rails...

Work on the Creed 75 is slow at present and not helped by the fact the workshop is a mess since I moved all the valves in there and thus had to relocate all the other junk. Having recently reminded myself that 1/4 watt resistors do not generally like being expected to sink 3 to 4W (!) I have some decent resistors to ensure the PSU gives the required 20mA. So I have 80-0-80V from the PSU attached to the 444, I have 20mA (actually 23), the 75 types to itself locally, which is mechanical, but does not receive correctly. I am generating code from the TDMS but Y comes out as Z and most other code combinations are unrelated to reality. I wondered if this was the result of the typehead not lifting correctly but Y and Z are on the same level. The ‘scope shows a reasonable waveform coming out of the TDMS. So, currently I have two teleprinters and neither one reliably prints out what is sent to it. Nor do they talk any sense to each other. I can accept that with the 444 as I still need to strip it down but the 75 is…

While viewing the UKuG webcast last night I lost the RHS sound in the headphones. Fiddling with the wire made no difference. The headphones in question are plugged into an audio mixer that connects the radios and PCs. Checking the speakers which are on a different output from the mixer showed the same issue, LHS sound only. As I wanted to watch the webcast I unplugged the headphones and plugged them directly into the MacBook, restoring the audio. Today, I pulled the mixer out and checked all the plugs. Checking audio from the FT450D showed it, too was only LHS. Hmmm. Figuring out it was probably time to take the mixer apart as fiddling with the pan and level knobs and main slider made no difference I caught one of the push buttons and heard a crackle. Pressing this a couple of times solved the issue. I do like these faults, just fiddle with everything and swear at it to fix. Brings back memories of the house TV in ancient times that would sometimes need a good thump! Very scientific... Now, do I bother finding the switch cleaner or leave it well alone and hope I remember which switch to…

I finally got myself a handheld satellite antenna - an Arrow II. It packs away quite small and is easy to put together, albeit you need to remember the size of the 2m elements when waving it about if constructing indoors like I did first time. I got the one without the diplexer because I plan to use two handhelds for full duplex rather than acquire a full duplex radio. Of course, the first order of the day was to try to bounce APRS off the ISS, in which I failed while waving said antenna about the shack. I received APRS easily enough but it was just too hard to try to track the ISS from the shack. I missed the good pass because the FT2D was refusing to see the GPS and I had not stored local coordinates - I have now. So, day 2 and I assembled just the 2m elements outdoors. Turned the FT2D on and it found the GPS almost immediately. I wonder just how much lead paint is on the shack walls! After figuring out where the ISS was on what was quite a low pass for us I picked it up and, finally got…

So I now have a functional Creed 75 teleprinter. The person it came from had done a first rate job at cleaning it up and getting it to function. Thus far all I have done is put it in the workshop waiting for me to make some time and space to have a play. I also need to get my head around it as I have never had a 75 before. And here it is. It is in good shape given how old it is and I hope eventually to be able to sneak this into the shack, aka the little bedroom. There is just no way the 444 would hide in there but there is almost a 75-sized hole. The innards do look neat and care has been taken in getting it working. More to the point though it prints just fine, a stage I have yet to reach with the 444. The first order of play is to get some volts onto it via the TDMS and make sure it receives as well as sends. Ah, that means I need to fix the TDMS which has stopped working. This also means I need to rearrange all the valve…

I thought it would be a useful experiment to make up a 23cm groundplane antenna. There is a useful guide at https://vk1nam.wordpress.com/2017/06/24/23cm-14-wave-ground-plane-antenna/ Using some 2mm copper wire from a supplier on eBay plus a N-type female socket the construction was fairly simple. Using the dimensions given above plus a bit for fiddle room I soldered the vertical element to the centre conductor of the socket. For the radials, given it was copper wire I decided to press my jewellers anvil to work and flattened the end of each element sufficiently to drill a 2.5mm hole. Using 2.5mm bolts each was secured to the respective mounting hole in the socket, and then the excess thread was cut off with a Dremel. Bringing it all indoors - the heavy stuff like drills and hammers live in the workshop - I calibrated my NanoVNA and gave the new antenna a go. It was a bit off but then each element was too long. Trimming each gave a fairly flat SWR where I wanted it. Well, almost, but near enough to stop cutting bits off! But does it work? Yes, I can open up GB3WC from the shack holding the antenna up inside the…