30m FT8

Just recently I’ve been dwelling on 30m rather than the usual 6. It’s generally quieter than 20 and I’ve made some really good contacts via FT8, surprising as the aerial is cut for 20 and 6. pskreporter shows I am getting out all over and I’ve had contacts as far as Kazakhstan and Oman, neither of which I ever managed on 20 or higher up the bands. Oman, in particular is right off the end of the dipole, although it does slope a bit at the ends as it is loft mounted. Not only that but I’ve received signals from much further than on 20. A lot could be down to them simply being swamped in the generally busy nature of the band but if it works it works.

I realise of course that I do need to get back to speech… but FT8 is just so convenient!

Ferrites

Those lumps you see on PC monitor cables and other PC and related cables… yes we know what they are and what they do but here’s proof.

I got a DisplayPort to HDMI cable for a new monitor. It works fine via VGA but why not? Anyway, aside from why on earth the PC has a DisplayPort and not an HDMI, the cable duly arrived. It’s a nice cable in that it has a braided cover, feels well made and the connectors fit well and do not drop out. But no ferrites.

All worked fine with both monitors – one DVI and one HDMI connected – came on fine. But when I key up the FT450D (set to 30W) the HDMI-connected screen goes blank. Completely blank. Black. It comes right back when I de-key. Ugh, no ferrites.

I fitted a decent clip-on to each end with a whole turn of lead in each – no problems since. See? They do work!

Cellular woes

The mobile provider we use is having issues right now with no data or voice services across the UK and including issues for those abroad using UK based accounts. It might be wider still. Of course there is no news from the provider and their website is apparently down for maintenance.

It happens. No doubt there will be some explanation in due course.

Twitter is alight – always a good source of gossip and alerts. But alerts on Twitter that fire off to a hashtag generate other issues. People use those hashtags to peddle their own, unrelated crud. And then there are confusing messages such as ‘Latest Trending in UK : “Three network down”. Find it on Amazon! ‘. But in general here is where Twitter comes into its own if you can cut through the dross.

Of course, there are numerous Tweets about the poor service with people saying they will leave and how bad it all is. There was one good Tweet from someone who said it’s the first outage they have seen in years and to wait it out. And that’s all you can do. Cellular networks are complex animals, and remember if something has a 99% uptime it can be down for more than three whole days a year, and all at the same time! Things go wrong.

Of course, I can still talk to the world via my amateur radio kit, running off batteries if needed, 24/7 with no other technology involved… just saying. Ok, joking apart it is worrying that we are increasingly pushing emergency communications onto cellular providers who are private entities responsible to their shareholders and not to us with what I am guessing are multiple single points of failure able to take down the whole country in one go.

50MHz

I can see the fascination with the 6m band these past few days. Lots of sporadic activity waxing and waning. Bearing in mind all I have is a wire dipole in the loft running roughly east-west I see plenty of FT8 activity from Europe and sometimes the Middle East, plus almost copied some SSB this morning. Now it has drifted off with only a couple of strong EU stations left.

For a week or so I’ve tended to leave the PC on running FT8 on 50.313 just to see how things go. It should be firing data off to PSKReporter.

GNURadio fun…

I have a had a real hard time trying to get GNURadio installed. The distro failed every time when running gnuradio-companion. This isn’t GNURadio’s fault, it may well be because my Ubuntu desktop has been upgraded a few times via dist-upgrade without it being a fresh install. Perhaps there is some old crud left in there even though I tried my best to remove all old versions of GNURadio and associated files and folders. After constant errors no matter what I tried it seems that my Ubuntu 18.04 installation somehow grabs GNURadio compiled against a previous boost library 1.58. So I resorted to the pybombs method which has installed a functioning GNURadio-companion despite errors with apache-thrift. Sadly, when installing gr-iio via pybombs it failed, again seemingly trying to refer to boost 1.58, rather than the 1.65 that the 18.04 distro has.

So… I purged libboost and grabbed the 1.58 code from sourceforge and set it off building. There are lots and lots of warnings but it did compile and install. Trying again to install gr-iio failed – it seemed to try to install boost itself and then whinged that the version is wrong. All deleted and purged again, still using the pybombs method and making it compile everything rather than installing the binaries. This time the uhd cod went in with no errors and GNURadio-companion runs ok except it has no rtl-sdr. Installing RTL-SDR did not help as a source file is missing… Installing the gr-iio package for the pluto also worked fine, and the FMComms block is there along with others such as PlutoSDR al categorised under Industrial IO.

After downloading an example .grc file that some kind person put on the web it works! I can see 70cm and see the result of a cq test call. Much to learn yet but at least the pluto is working in receive with GNURadio.

As an aside, while waiting for pybombs to sort everything out – and it took ages on uhd – I installed sdrangel which has a .deb package that works with Ubuntu 18.04. After figuring out that it installs itself into /opt rather than /usr I fired it up with the pluto attached and I can make the pluto receive on 70cm.

I’m sure the lesson here is sort out your Linux installation rather than continually fiddling with it like I have. When I get some time I plan a fresh installation of 18.04 and getting GNURadio from the distro to see if it works that way.

Project 444…

…the slowly ongoing saga. Typical. I wired up the 50-way D connector and connected it all up and … nothing. On checking voltages half was missing, i.e. -80 was there but no +80. The barretter was open circuit on one side. Huh.

A new barretter arrived via eBay and so I now have the PSU fully working. A quick check of the 444 showed it to be no better than before, which I’d expected but I really wanted the correct power supply to verify that. So I connected up the TDMS to send data to the 444 and with the keys set to SMSMS it reliably prints Y – pity that should be R! Fiddling with switch combinations is equally confusing.

So, progress, of sorts. However, the TDMS itself needs work yet because the circular trace is far from a circle, or indeed not even close to anything which might be imagined to be circular.

Sleeping teleprinter

It’s beginning to look serious now…

I just need the time to solder up a 50-way D connector to connect the interface unit on the right to the 444. The interface has the +/- 80V supplies inside as well as all the interface logic for the various teleprinter functions. if I nick some volts out of it I should then be able to feed in the test signals into and out of the TDMS and use those to align the 444.

New toy… (updated)

My latest toy arrived on Monday, a TDMS5BV telegraph distortion measuring set (TDMS). This guy (hopefully!) can generate a test pattern and all sorts of other magic to help test circuits (not particularly relevant) and also teleprinters (definitely relevant).

It tests polar relays too, thus the socket on the front. I have a PDF of the manual and schematic for it. I now also have a variac so I carefully brought the TDMS up to voltage while watching the current and all seemed well – no exploding electrolytic. But it did nothing. After bothering to read the manual it gave instructions on how to prepare the instrument. After a fiddle with a control at the back it produced the required circular(-ish!) trace and the polar relay started to cycle. So far, so good…


Weather… and all that sort of stuff

Well so much for me tinkering with the satellite dish to receive QO-100, the dish arrived and the weather arrived too! We had days of very strong wind and horizontal rain and then when the weather got better I had railway stuff on. Sorting the valves out just made it worse as the dish is now buried in the workshop. Anyway, the valves are leaving next week so I will have space (Space for space, get it? Ok, I’ll get my coat…)

This is the pile of valves to go so you see the issue facing me workspace-wise. There must be 1,000. There is half as much again behind the boxes. This finally rids me of any non-CV marked valve and all are going to a better place (no, not the dump!). And yes, those are 5 of the 21 VT98-type valves I imported. The guys at the depot managed to get all 21 crates into my (then) Astra hatchback – they were a lot better at packing that I am and I’m pretty good!