Yesterday afternoon I got the compass swing done. In principle, it should be done with the engine running, but I need to minimize ground running time as the engine is not yet broken in. So, I did it with the engine off, but the avionics system, strobes, etc powered. I’ll do another compass swing with engine running once the engine is broken in. The flux valve for the Dynon EFIS is in the rear fuselage, so I’m convinced it would not be affected by the engine.

The Dynon EFIS compass had extremely low errors after doing its calibration procedure. The errors on most headings were either zero, or one degree, with only two headings having two degree errors.

The standby compass was not so accurate, as it is apparently badly affected by magnetism in the steel roll bar. I have a line on a degaussing tool, and I will give it a try sometime after first flight. CAR 605.14(d) requires

a magnetic compass or a magnetic direction indicator that operates independently of the aircraft electrical generating system

For now, the way I read CAR 605.14, the magnetic compass in the Dynon EFIS is sufficient to meet the requirements, as I have the internal battery, which allows it to operate even if the aircraft electrical system is dead.

There was a C172 doing circuits, so I was able to get a radio check on both the GNS 430 and the Microair 760. The Microair 760 is hooked up to an antenna inside the left wing tip, which will provide less than optimum performance (but zero drag). I was encouraged that the pilot in the C172 said the signal was strong and clear. It will be interesting to hear how it does with longer range reception and transmission.

I'm relieved to get the radio checks out of the way, as there would have been an awful lot of wiring to troubleshoot if things hadn't worked - two radios, each with several wires going to the intercom box, several wires between the intercom box and the headset jacks, plus two antennae, etc.