Portsdown progress

It really is taking me far too long to get this sorted out. But, finally some progress has been made… at least I now have a decent case and the screen mounted. So far, there is very little else in the case other than the Lime and Pluto, the screen, the Pi and a 12V to 5V converter. But at least there’s plenty of space to add all the other necessary bits and pieces.

The screen was the most awkward thing to mount as it is designed to fit easily into a plastic surround with the Pi directly behind. For that, the 4 mounting screws fit directly to the case. But here I want it in the front panel. My rather less than elegant solution was to get some 1/4″ square aluminium bar, make holes for 4 M3 nuts and bolts and tighten these to become studs – these are in the horizontal pieces as shown in the pic. These were then epoxy glued to the front panel. Two more bars then take the screen, with spacers so the screen isn’t pulled back too much when tightening.

Anyway, elegant or not you can’t see it from the front! Still to go on yet are the three push buttons and encoder / tuning wheel for the Langstone transceiver part of the kit. As for the rest, well, one thing at a time! But anyway it works… as shown by yet another successful 6″ transmission to the Winterhill box sat on top!

Portsdown upgrade

I’ve upgraded my Portsdown setup to Portsdown 4. Setup is used in as loose as possible a way here as it’s basically still a box of bits. This needs a Raspberry Pi 4 which arrived today, freeing up the current Pi 3B for use elsewhere. The docs suggest a 2Gb version but I got the 4Gb one. One slight hiccup is that the Pi 4 uses a USB-C for power so I borrowed a phone charger lead temporarily.

I must say that the upgrade was very easy. Well, ok, the actual upgrade was attaching the Pi 4 to the back of the screen and downloading and installing the software on a freshly cut SD card, not upgrading the existing software. But, easy – ssh into the Pi and run 3 commands pasted in from the software page. Or simply buy a pre-cut SD card from the BATC shop.

I also had a Pluto lying about (there, loose terms again in action, it was actually aimed to be the RF part of a Satsagen spectrum analyser setup, but hey). One thing I had not realised is you can run both the Pluto and the Lime Mini together, just not at the same time, so no wastage of the Lime. It also connects to the Minitiouner (V2 only which mine is).

But the icing on this particular cake is that with the Pluto one can use the Langstone microwave transceiver  which is, in this case anyway basically an add-on package that is installed from an option in Portsdown via the touch screen. With the addition of a USB audio sound card dongle, which I had, plus my Heil headset it turns it into a transceiver able to work multimode across the amateur bands from 4m to 6cm with further plans in the pipeline.

And, like the Portsdown installation itself, setting up the Langstone was equally easy. Hats off to all those who made this excellent product so easy to set up.

More info at https://wiki.batc.org.uk/Portsdown_4 and https://wiki.microwavers.org.uk/Langstone_Project

One thing to note is that the Pluto output is very rich in harmonics so filtering is a must. Not got that far yet! I need a box first.

More ATV fiddling

After finding the dead LCD screen that was to be a 5.6GHz ATV receiver it also turned out that the 7″ Pi screen on my Portsdown setup had similarly died – just white lines on the screen. No amount of stripping, reassembling and general fiddling fixed it. A new screen did.

Anyway, I now have a Winterhill receiver. This came from a fellow ham and saved me building one. As is usual with any new box one absolutely must try it right away, which is how I discovered the bust screen on the Portsdown. After that was replaced I successfully sent a test card 40 inches across the desk! Small steps… and at least the Winterhill is in a nice box unlike my Portsdown which is still waiting for a suitably sized case – why is it all the nice metal boxes are a few mm lower than the 7″ display needs. Huh.


Since I built the Minitiouner I’ve had nothing to test it with except a quick test on the Astra satellite to prove it actually worked. Not any more. I now have a Portsdown ATV transmitter setup thanks to a recent advert for one for sale (saved me having to get all the bits). No PA, no antennas or anything else here yet, but I did at least manage to send a test card from it to the Minitiouner over 23cm and at the grand distance of 6 inches.

It all needs a nice case yet but it’s a good start. This might even persuade me to bung my 23cm yagi on the chimney and see if I can actually receive GB3YT – it’s not too far away but there is a house in the way.



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