On a more positive note, the Aircraft Radio Licence for G-JONL arrived today so I am now able to test the transmitters properly, on air and into the antennas. Unable to progress the general instrumentation, I therefore decided to check out the radio systems.
G-JONL has two communications radios (Com 1 and Com 2) plus a navigation radio (Nav 1) used for tracking en-route nav aids and for instrument landing approaches. One way and another there's quite a lot of cabling and many interconnections. Most of these had been tested in isolation but today was
the first time that I connected everything together and performed an end-to-end test. The picture shows the avionics stack propped up on a box for the tests.The result was a qualified success. Com 1 works just fine on both transmit and receive, from both the P1 and P2 seats and Nav 1 picks up the Dean Cross VOR and provides a sensible bearing, even with the aircraft in the hangar. Unfortunately, Com 2 is seriously deaf and as yet I can't really determine why. The antenna appears to be OK when I check it with an antenna analyser but both transmit and receive are significantly worse than the Com 1 performance.
I'll take an SWR meter up to the airport tomorrow and see if that sheds any light on the matter. Certainly the symptoms seem to indicate an antenna problem, even though the analyser gives it a clean bill of health. Lobbing a few watts at it and checking the SWR seems to be the next logical check to do.
I did a few other things today. Firstly, I aligned the rudder by adjusting the turnbuckles so that the rudder pedals are in line when the rudder is in its neutral position. I also made a start on fixing the seat backs - I've decided to try using Velcro and that has necessitated attaching aluminium strips to the back of the seats for the Velcro stick on to. I did the P2 seat today and it seems to be fine, so I'll have a go at the P1 seat tomorrow.
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