Amateur radio (250)

M0RVB

ISS SSTV event 2020

I am rather late for this event which runs from the 24th to 31st December 2020. Due to all manner of things, Christmas included, I only managed to have a go at receiving the images on the night of the 28th. The ISS pass was in the early hours so I just left things running. Among several partial images including identifiable bits of 3 of the 12 images I found this one: Not too bad for a co-linear mounted inside the loft with a snow covered roof. I actually saw another image arriving from the ISS while approaching Spain at around 10:25 on the 29th. Typically, in my rush last night to set everything up I forgot to tick the 'Auto slant' setting in QSSTV...

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M0RVB

PiBox progress...

The PiBox is almost completed. It's taken far too long due to all sorts of silly things like having to get fans because a dry run indicated the poor little boards were getting a bit hot, having to get bolts for the fans because I had none long enough, and having to get a connector for the 1-wire (actually 3 wires!) lead from the central heating sensors. So, there is is. Two fans on the left, 5V PSU bottom right, gigabit Ethernet switch above that, then the Pi's: top is the PiStar with the DVMega board which has coax to the rear panel and then a dummy load, middle is the ASD-B and central heating monitor Pi, and the bottom is a general purpose one with various bits on such as rtl_tcp. The lower two boards have USB-A sockets on the rear of the case for the two SDR sticks, one for the ADS-B antenna and one to attach to a Discone for general use. But there is an issue. I had originally intended this to sit in the shack but those fans are just too annoying. Not loud, but constant. I suspect the box will end up in the…

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M0RVB

The full exam

Well I passed the full licence exam a couple of weeks ago now. The RSGB were particularly quick with things as Ofcom knew the Tuesday after my Friday exam, meaning I could chose a callsign, and the pass certificate arrived from the RSGB in the post the next day. Here are a few notes while I remember in case they are useful to anyone. YMMV of course and different things work for different people, you need to do what works for you. As you should know by now you need two cameras, the one on the laptop (or attached to a PC if that’s what you use) showing your face, plus another off to the side looking across. I used a MacBook and an iPhone as second camera. Positioning the phone was something I had thought out but got wrong on the day. I borrowed a phone stand for this but it proved impossible to get the angle right. This second camera needs to look across at you and the keyboard and screen and I ended up propping the phone against the stand having placed the stand on its side. It only fell over once which made me jump as…

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M0RVB

Raspberry Pi and SDRs

I had an idea that my RSP2 SDR could sit in the loft driven by a Pi in the shack. The Pi in question had DireWolf and a DVB-T stick watching APRS traffic. Ideal, I though. Hmmm. I really thought this would be easy and a web search suggested that it should all work, my plan being to use the Pi to serve the SDR remotely from one of the laptops.  My first attempt was to install a fresh Raspberry Pi OS and install SoapySDR and SoapySDRPlay. However, various bits of SoapySDR failed to compile due to some things not being found, even though I followed the instructions to the letter. A web search found only two identical but unanswered questions, so no help there. More searches. SDRPlay have a useful looking image for the Pi where it will run in a number of modes, including soapy remote. This seemed just what I wanted. It all went in and the Pi throws open port 1234 which web searches indicated as the right thing for it to do. However, SDRPlay refuses to play whatever I try. I have again followed what instructions I can find regarding remote operation, some of which…

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M0RVB

FT450D MARS modification

In preparation for me receiving a full callsign (having just passed the full licence exam - yay!) I wanted to get the FT450D ready for 60m. Out of the box it comes with several pre-set frequencies that do not cover the available band slots and so the only recourse is to perform the MARS modification to the radio (aka ‘widebanding’). I uploaded the latest firmware first (v 244). Note that the firmware upload resets all the various settings so in my case I had to wind the power back down, set the CAT baud rate, and set the data type ('D Type') to USB. I found two different sets of instructions on the Web, one referring to jumper JP4002 but another had a different number. However, one page had photos as well which tied in with what I could see. The instructions there are clear and are what I followed, the URL is https://radioamateur.us/ft-450d-mars-mod/ Following those instructions I took photos of each stage and have added a few notes below. Note that you do any modifications at your own risk and very probably voiding any warranty - I believe Yaesu will carry this modification out for you but this is…

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