Radio, railways, stuff...

M0RVB

Clock

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 is the actual timestamp. Thus if you feed that data to a clock display it runs slow. (being lazy and saying GPS everywhere, I should really use GNSS!)

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M0RVB

ISS SSTV event October 2024

So far I have received two complete but very noisy pictures from the current ISS SSTV event. The first was 11:37 UCT on 9/Oct/2024 and the second was at 13:12 on the same day. Both were as the ISS passed to the south of my location and right out over Germany, for the first picture and France for the second. I could hear SSTV signals as the ISS was approaching from the west but far too weak to decode. The transmission of the second image began as the ISS passed over the west coast just south of Wales and continued across the UK and across France. I can't remember exactly. Anyway, here are the two pictures: Both images were received on a 2m QFH antenna in the loft. While waiting for the signals to become strong enough I tried other antennas: the collinear heard very little, the big wheel did better but the QFH was superior.

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M0RVB

Antenna moves

Another Hamfest is over... 160 mile round trip for me (ok, plus a diversion where I followed the signs to a service station which were ok until the last junction and I ended up on another motorway!!) but not a bad trip. Except for the roadworks on the A1... Anyway, a 6/4/2/70cm collinear came home with me and it is now installed in the loft replacing the existing 2/70cm one. Same cable etc. I also finished off the boarding over one bedroom - surprisingly the one where the antenna is and no, that's not the reason for completing the boarding. Honest! It has, as one may expect very little gain at 6m and 4m but replaces the 4m ground plane that I had and was rather in the way. Plus I never had any form of vertical for 6m. I also managed to today the antennas up a bit. The 70cm big wheel is now no longer under the 2m big wheel and has its own place farther away. The 2m big wheel has moved so I can actually walk across the loft without needing to crawl under it. I also recently acquired 2m and a 70cm QFH antennas from ft8.co.uk. These are really well made, being constructed from copper pipe and waterproofed. I will be experimenting with QFH antennas but wanted proper ones due to (a) being too lazy to build right now and (b) even when I do build one I need something to compare it to. Currently only the 70cm one in set up, in the loft again, and replacing a discone which was also in the way. This feeds a Cross Country Wireless HF-UHF antenna splitter and provides the antenna for three LoRa modules, one for TinyGS, one for radiosondes and one is a LoRa APRS iGate (RX only). The satellite reception report via the TinyGS console shows the antenna is working really well. My plan though is to replace this with a parasitic Lindenblad (seeing I am building one) and then actually use the two QFH antennas for satellite work. The only downside there is the need for more coax feeds into the shack from the hole in the ceiling, said hole already being full. But at some stage I need to enlarge it to run the LDF4-50A up for the QO100 dish once I move that from the garage wall. That will be a major tidying-up exercise!

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