cwatson

All working like a charm. Hear calls from all round the state, as far south as Rainbow beech and out to Emerald. I think the next investment for the tool box will be a dummy load. Never needed one before, but from what I now see will be very handy for diagnostics.

Hi Issue has been resolved, at least until proven otherwise. SWR meter tests were very bad, and fault was located to be faulty BNC connector on the bottom of the antenna. Connecter wouldn't clip in properly, and so had vibrated loose. Replaced BNC connector and SWR now 1.3. Power readings right on spec as well. Experimented with headsets, BOSE v's passive talking into one and listening in the other, and yes the mic on the BOSE is much more responsive to the passive. Tuned all the volumes to suit the BOSE, and now have nice discrimination between the audio signals again. The system is balanced so can still use the passive if needed in a flight, but would be a bit quiet until radio adjusted. Will have to decide what to do for a second headset long term though. Very happy with results, Cheers All.

Bob, I spoke to Kev from XCom and he was very helpful, and I now have a couple of things to play around with. He said a bad SWR can cause damage to the output drivers & also some receive circuitry. I am not suspecting this to be the case though. My SWR meter turned up today so I can check that and power readings over the weekends. The other problem he has come across, more with the lightspeeds is the mike gain being to high and overpowering the system. There is some tricks but the light speed can be adjusted with a bit of no how. The bose however is not adjustable. I have noticed though, that the volumes on the Bose control are always set very low to stop you blowing your ears out. Generally the receive volume is acceptable, but sometimes the inbound calls can be a bit soft. It comes down to my originally feeling, that there is an imbalance in the way it is all setup. I'm going to play around this weekend with a few options, including using the mike of a standard headset while listening in the bose. I assume the bose is amplified, and may be just too strong for the radio, although the intercom volume isn't that much different in level if the headset is turned off. See what happens after some testing. Cheers

Thanks alot, that is the music to my ears. Have called M Coates a couple of times but they were busy / engaged, so will try again this coming week. Cheers,

Trying to remember back, the loading coil shortens the physical length while maintaining the correct electrical length? I presume these Comants lie back at 45 degree's for aerodynamics and to look pretty on modern aircraft?

Hi That is a very good point, hadn't checked the receive squelch, had setup the intercom squelch properly, but not looked at the main one on the front panel. I had thought about doing a factory reset on the radio and starting the setup from scratch again, which I probably will do and will make sure the squelch is set on the minimum required. The other thing I have noticed, is the call's I have missed have all been from aircraft on the ground while I am in the air. My antenna is mounted onto of a square fuselage so is slightly in the shadow. One was actually from a aircraft at our strip while I was in a circuit. I have aslo found that these Comant antennas are ground dependant, which I didn't realise. I had assumed they would have a loading coil and be ground independent like UHF. The next step is to buy a SWR meter and measure antenna performance. I have sprayed alot of ACF 50 through my airframe over the last 12 months and have had the landing light stop working due to earthing. I now have to run an external earth for it up the strut to the wing. After checking the antenna, I will replace the washers with shake proof ones which will penetrate the aluminium and make sure the antenna has a good ground plane. I want the SWR meter first so I can see if there is any change. I would say it could be a combination of a few little things adding up to a problem.

Hi, I am running a oldish XCom and now a Bose A20 headset. I have found that there are times that I am not receiving radio call's and are looking for some input. Need to work out if it is a headset issue or compatibility with the radio. The radio has had a full upgrade, including firmware and output drivers so is supposed to be equivalent to the latest model. The volumes are run on the high end, so should be plenty to trigger the headset. I also notice the headset doesn't respond to the radio volumes, and must be adjusted on the headset. This is also abit annoying as there is no discrimination between the calls (internal / external) but I assume is just the way it is with ANR headsets. Haven't had an issue with my old clunker headset, but quality and comfort is far from what the Bose definitely offers, so are keen to understand what the cause is so it can be repaired. Cheers, Chris