More Savannah instrument panel

Today I finished stripping out all of the surplus cabling that had been used for the old radio and intercom set up and identifying all of the connections that I’ll need for the new radio and transponder. As I suspected, although I didn’t come across any more bare connections, the wiring for the previous installation was shambolic and I look forward to making things much neater behind the panel before I’m finished.

One of the things that I found very bemusing was that the power cable feeding the radio had been wrapped around the main panel wiring loom in the form of a long coil. Now I’m no expert, but I think that that’s a no-no for any radio because the coil form has the potential to act as an antenna and introduce interference into the system, which is just what you don’t want. Anyway, I won’t be doing the same thing when I come to connect the new kit.

I also spent some time today thinking about the new panel’s layout and trying to come to a final design, which I think I now have done having had the old panel lying on my kitchen floor for several days and looking at it every time I walked past it. Unfortunately, I’ve had to come to the conclusion that the panel is just too small to incorporate a tablet to run my navigation software so that has had to be left off. The design I’ve finally come up with is as shown below.

The changes compared to the original layout are only slight and quite subtle in that I’ve changed very little on the right and left hand sides of the panel. The reason for not adding an extra gauge into the group on the right hand side is that the existing gauges are all 52mm in diameter and if I’d shifted the fuel pressure gauge over into that area it would have stood out like a sore thumb because it is a 57mm gauge and also has four fixing screws which the 52mm gauges don’t. I’ve not changed anything over on the left hand side, the pilot’s side, apart from swapping the 57mm rev counter for the new 80mm one because there isn’t really the potential on that side to do anything significant to gain space and certainly not enough for an extra gauge.

What I have done is change things in the centre of the panel. I’ve carefully measured the space available and I’m 99% certain that if I move the RPM and VSI gauges a little left of where they are in the current panel there will be enough space between them and the right hand vertical row of fixing holes to get in two columns of 57mm gauges. This means that I’ll be able to have a slip ball and the existing fuel pressure gauge on a top row and the new radio and transponder on the bottom.

There are a couple of advantages with this layout. First, by having the radio and transponder on the bottom row, the ‘D’ plugs of both units will be readily accessible. This will be especially useful for whoever programs and initialises the transponder for me because it will be possible to do the job and the subsequent testing ‘in situ’.

The other thing is that both the radio and the transponder require 3 amp in-line fuses and because there will be enough space vertically between the lower and upper rows of the 57mm gauges in the centre, I’ll be able to have 3 amp contact breakers in the panel as shown, above both the radio and the transponder. This will be much more convenient (and professional) than having in-line fuse holders that you’d have to reach up for behind the panel as was the case with the old radio that I’ve just removed.

I’ve ‘lost’ a week because I’ve not heard from my German supplier since last week-end, probably because he was at the show at Friedrichshafen all week that has just finished. I heard from him again today so I’m hoping that I’ll receive all the new kit by the end of this week. It’ll be too late for me to make my first window for flying to the UK (leaving 20th April) but I’m hoping that despite having to get everything fitted and installed and the transponder initialised and tested, I’ll make my next one leaving the following week-end. All I can do is press on and do my best 😉