Radio, railways, stuff...

M0RVB

DV-MEGA

Just got a DV-MEGA single band 70cm Raspberry Pi hat because I wanted to have a fiddle with a hotspot for the MD380. I can get into three (sometimes four) DV repeaters from here but I do like to play with tech. This little board plugs into the Pi’s GPIO connector. I already had a spare Pi 3 from an abandoned PVR project and a PoE power unit so why not. The board will take an SMA arial directly but mine has a dummy load screwed in instead. I’m using Andy Taylor’s Pi-Star package from http://www.pistar.uk/ - from there one can download a complete image for various boards including the Pi which, when imaged onto an SD card results in a Pi which boots up headless and presents a really nice web interface from which all configuration and monitoring can be carried out. And it works really well. It is a doddle to set up and configure, especially given an instructional video https://www.youtube.com/watch?v=B5G4gYDdJeQ Anyway, it also made me reconfigure the MD380 as the codeplug I had made previously was a little disorganised. I now have all four local repeaters set for all the useful talk groups in two zones each (the radio can only have 16 channels each, awkwardly), including a zone for the simplex channels which I had forgotten (!) and a separate zone for my hot spot, that one with the tx power set to low. The channel is set to colour 1, a lot of people seem to use 438MHz as the frequency (NB both tx and rx), and TG9. The slot does not matter as it’s simplex. Connecting to a talk group is straightforward on the MD380. Menu -> Contacts -> Manual Dial and then enter the TG number e.g. 4400 for the UK wide one and press the PTT. You should hear a voice telling you that you are connected. Use 9990 for the parrot, and 4000 to disconnect. QED.

Continue reading...
M0RVB

National Hamfest

Having finished a major bit of academic work I treated myself to a relatively short trip down south to the National Hamfest yesterday (Friday). This is my first trip to such a thing since the radio rallies of the 1980's and I had no idea what to expect but I can say it was worth the trip, if only to see what I can't afford to buy! I didn't come away with much - I grabbed a pair of Nagoya NA-771 aerials, one for the UV5R and one for the MD380 (different antenna connectors of course!) and one of QRP Labs excellent 5W single band transceiver kits for 40m. The manual (PDF) is a work of art giving detailed instructions of every step of the way including photographs to show what things should look like. This is waiting until I pass the Intermediate exam. Oh yes and an SDRplay RSP2 followed me home too. Unfortunately the SDRuno software is Windows only but CubicSDR works fine on the MacBook and with very little fiddling I'm listening to SSB on 20m. I've used CubicSDR on the Linux box before so not too steep a learning curve. The RSP2 has two antenna inputs and the switch between these is in the software - so an option in CubicSDR for example.

Continue reading...
M0RVB

Solar flares

I had WSJT-X running just in case I had time to make a few QSOs while writing. There was plenty of activity and numerous decodes but I'd not had time to play. Then there was a cryptic decode at 16:09 UTC which just said 'SOLAR FLARE'. The timing and frequency suggest it was someone a few squares away. And sure enough, no more decodes. At all. I switched to WSPR and recorded a couple of stations that way, and was recorded by a couple too, but it's very dead. I wish I was watching the waterfall when it actually died off... anyway, not long after it seems to have recovered as I can see traces again and it's decoding.

Continue reading...