Getting hands on now

Not yesterday, today. Yesterday wasn’t a very nice day – rainy and a bit windy – so I spent the time indoors finishing off my little microelectronic gizmo, which has to be done in order to finish off the Savannah’s new instrument panel. I first trimmed its circuit board down to size and then made a little plastic container for it out of 1mm polycarbonate windscreen plastic.

I first tried sticking it together with superglue but it was very messy and didn’t work. I then decided that as the board and its components were to be encased in silicone inside it anyway, I may as well try using the silicone to hold the tray together, and as the following images show, it worked.

I’ve kept the end connections on the Arduino microprocessor that are used for programming it clear of silicone so if necessary I can reprogram it in the future to modify the revs at which it will start and stop the hour meter recording but for now all I can do is wait until the instrument panel as a whole is finished and installed to see whether it works as planned.

Today was the day when work on the aircraft itself began as a preliminary to being able to install the instrument panel. The first job was to fit the new transponder antenna. I had noticed the following holes in the underbelly of the Savannah without thinking too much what they were there for but as soon as I set about ordering the new avionics fit I knew instantly.

They were there because a transponder had already been fitted at some time in the past and then removed, so by ordering the same antenna that had fitted into them, I could fully re-use them and make a neat job of the new fit.

Getting the antenna cable through into the cabin was the simplest of jobs because there’s an unimpeded route below the seats.

However, the best route is along the side of the fuselage and cabin, where all of the other cables have currently been run.

Here’s how it came out inside with the antenna cable attached.

And here’s an external view of the new antenna. Very nice I think

The cable entered the cabin on the passenger (right hand) side at floor level. My only concern is that by running the transponder antenna cable alongside the radio antenna cable there will be interference to the radio signal, but I’ll just have to wait and see. If so, I’ll have to move the transponder cable over to the left hand side.

Both cables now pop up in front of the passenger door and will cross over to connect with the radio and transponder in the lower centre of the panel.

My next problem is to sort out the radio connections that are present so I can solder up the wiring looms for it and the transponder. The latter will be easy – just two wires – but I’m still trying to resolve which of the wires coming down from the headset jacks are for the microphones and which for the headphones as although I don’t think that connecting them the wrong way round will do any damage, I just don’t want to waste the time having to take them out and resolder them. I’ve emailed Alphatec, the maker of my headsets, to see if they will tell me but time is pressing and I won’t be able to wait longer than 24 hours before pressing on and finding out the hard way 😕