Radio and rails...

Having now had a chance to take a closer look at the Creed to see why when Y is sent by the TDMS it prints as Z it is clear why! The following shows why... the TDMS is sending a continual stream of Y's and then R's: This is the system between characters, all is well, but... ...this should be a Y, i.e. MSMSM (M = mark, S = space), but prints a Z, i.e. MSSSM. And the R? This should be SMSMS, not SMSSS as shown. SMSSS is carriage return, no wonder then why the typehead remains firmly at the left of the platen. But, checking the waveform output from the TDMS shows it is indeed sending a Y, and with a good square wave. This gets rather mangled when the teleprinter receive coil is connected but still has sufficient peaks to drive the thing. So the issue is between the input to the teleprinter and the selectors. One item to note though is the three photos above are from a video recorded on my iPhone in 'slo-mo' - which proved to be really very useful here! Time to read the manual more closely...

I’ve been planning for a while now to put up an antenna in the garden, but where is the question. I have a 20m wire and 9:1 unun to set up somewhere - ideally I’ll run this up the garden but that goes under the phone line, or actually the end of the wire would be under it. What stopped me was the impending changes for EMF as the unun would be mounted outside pretty close to our bedroom window. So, for a laugh I got another unun to experiment with (yes I know I can make one but the ferrite I had is lost in the workshop moves). Looking at the ‘ideal wire length’ chart 36 feet comes close enough to the distance between the bedroom/shack and the hedge so I cut 36 feet of bell wire and launched it across the utility room towards the workshop as a measure. Tied to the bedroom window reached almost to the far side of the workshop. I reckon I can attach a pole there and attach the unun to the wall outside the shack - there is a convenient airbrick nearby. But, for a laugh I attached said bell wire to…

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…