M0RVB ⁽²⁹⁴⁾

Another of my hobbies, if you can call it that is that I volunteer at a heritage railway in the Signal and Telegraph (S&T) department. We maintain the signalling along the 4.5 mile railway which includes three signal boxes and numerous signals, points and telephones. Occasionally I get homework. This week it is working out the resistance needed to drop the voltage across the track at one point to a level suitable to power a relay. This is for a track circuit, in the case in question across a set of points. With the track circuits we use the section of track concerned, which is isolated from the rest of the railway by insulated block joints separating the bits of rail, power is fed to the rails at one end and a relay is connected at the other. The voltage needs to be sufficient to keep the relay up and this indicates that there is no train on that section of rail. When a train is on that track the voltage is shorted out across the wheels and the relay drops to indicate the presence of a train. The relay concerned is similar to the one shown below and has…

So... Wordpress has gone to war it seems. Now I don't use WP Engine but moves like the current ones do make me worry about maintenance of Wordpress itself, especially as I run it on my own server. When I consider that along with the fact that there is a constant stream of hacking attempts against my server many of which are attempts to get into the Wordpress installation I had to re-think my use of it. To make matters worse since we got upgraded to FTTP I ditched my rented VPS and moved all of my IT stuff to here. So my Wordpress runs on a box downstairs and I would rather it did not become a doorway for tinkers to get in and tinker. Plus the fact that for my little blog a full installation of Wordpress and its associated mysql database, where every page is rendered after the data is fetched from the database server is rather wasteful on resources. Also the theme I used incorporated Google fonts and I then needed a plugin specifically to get rid of those fonts. I would rather not be the reason someone's browser connects to Google for anything. So here…

I've been looking over the QSL cards I received with the view to somehow printing on the back, given my handwriting is worse than any doctor, or spider... Like many my QSL cards have a printed back to add QSO information in predefined boxes. I thought I could probably sort out a template for Apple's Pages word processor to print the rear of a card. Some cards I received simply have a label stuck on the rear positioned top right with all the information on. That seems typical of special event stations or, I guess people that send a lot of cards. Another example, similar to mine has a longer label with details overlaying the pre-printed boxes and having almost the same design as those boxes. I guess that makes it easy to either print a label or fill the card in by hand. Many of the cards I receive are hand written, all with far, far neater handwriting than mine! So I wrangled Pages and got text in approximately the right places as an experiment. I figured out how to define a page size of QSL card dimensions and hit print. As expected the printer was sat waiting for…

A couple of days ago I was looking for a stand for the FT5D and found a rather nice leaning one to 3d print. Today I found similar stands for the ID51 and the MD380. All three duly printed and lined up...

I finally have a UTC clock (it does other stuff too). This is a QRP Labs Clock built from a kit of parts plus a GPS receiver, also QRP Labs. Very simple to build. It runs from 5V (pity it's not 12V but there you are) but I recently acquired a 5V linear PSU to run the three little LoRa boards rather than the 12V/USB charger I currently use. The kit is not yet finished - I need to attach the power switch and connect those two push buttons - but it's a neat little thing in a nice case. I was looking for a GPS locked UTC clock and recently built a kit which is also a 10MHz source and has a 10MHz OCXO to make a really useful device. That also has a clock display as well as other dispel modes such as satellites, locator and such but the clock is always about 1 second slow. Reading through the documentation from QRP Labs it transpires that this is because the 1PPS signal and the NMEA data can overlap, so the data stream from the GPS that shows date and time is not aligned to the PPS pulse which…