I suspect ChrisB is long gone 
That post was 6 years ago. He would have received a notification but if his email address is duff he won’t get the email.
Maybe @wigglyamp has any ideas?
Did you get your static problem solved? I just finished a 7 year restoration of my PA 20. I’m having what sounds like the same problem you’re having. I’ve isolated the radio power supply. The only pull breakers in use is the avionics master and the radio. I’ve removed the radio from its mounting bracket behind the instrument panel and allowed it to dangle away from any radiation or emissions. Didn’t change anything until I removed the antenna coaxial cable to the antenna from the radio. The cable and antenna work working perfectly with an ICom IC-A200 radio.
I’m stumped?
Mark Moyle
Platinum Alaska
If the wiring is completely made as differential system that emmission and immunity should be quite ok. A cullprit could be combining the differential grounds at the plug. In general if you have emission or immunity problems you have created a loop with a certain area. The larger the area, the more sensitive it is for emmision and immunity related problems.
Shielded wiring I normally would use on this installations are also twisted pair. Twisting wiring is also a known solution which can hugely reduce emission and immunity problems. This could easily make a 20 – 30 dB difference, which is huge.
I don’t know where you are located @ChrisB, but you would always be welcome to stop by at EHMZ (after making an appointment). We have quite some specialized EMC gear to troubleshoot this kind of problems, both from an emission point of view as an immunity point of view.
Chris, did you try Jesse’s suggestions from #20? The answers could help a lot!
(excuse me, pls ignore, I overlooked #23)
Peter, a kind offer, thank you. PM on it’s way.
Jan,
I can certainly try the ferrite beads but I know nothing about them, I’ve done a quick search and RS have 617! Can you point me in the right direction?
I will look into making a recording.
Chris,
There remain Peter’s suggestions for adding ferrite beads or similar to the data wires – it takes neither a lot of effort nor lots of money. Give it a go, if it doesn’t help it cannot hurt. You could even experiment with shielded wire, earthed either on one side or on the other or on both. Or did messrs. Trig do these things already?
Also, I am curious about the character of the noise, but this is very hard to describe in words. Do you have any way of recording it and posting that recording, perhaps as a movie with no images?
Well, I wish there was something wrong with my installation or units! I wish I could join the list of you guys who have had no trouble.
As this thread has progressed a bit, let’s review the facts…my installation is in a part-built wooden airframe with no other electrical stuff except the battery, switch, antenna and radio. There is no stray rf or bad grounds. I have noise in my headset, which after extensive correspondence and live testing of my stuff, Trig have admitted that the noise is there and is caused by the link between the tuning head and radio box. Trig have made a new harness for me from scratch, but it has made no difference. They have offered me my money back because I am suffering from a problem which they acknowledge does exist but which they, at the moment, are unable, or unwilling, to solve. I’m not suggesting they make a poor product. It appears that there are a lot of people out there who don’t have this problem. Again, I wish I was one of them, but I don’t understand why others have no problem when Trig themselves admit that the noise is present. I do, however, wish that they had been more up-front from the start and saved me a lot of to-ing and fro-ing.
My purpose in starting this thread was to enquire whether anyone else had this noise. Evidently the answer is no, so I am as baffled now as I was then! It seems I have two choices, either throw in the towel or buy a noise-cancelling headset. I don’t really want to do the former because the whole point of choosing the TY91 was because of its separate tuning head which fits nicely in my panel where other radios won’t. I was really hoping that they could come up with a fix but it seems that offering a refund is the quickest way of stopping me pestering them! Maybe as a previous poster suggested they have moved on to bigger things.
I’d like to thank all who have responded and it’s a shame that my problem remains unresolved.
It also means the tuning head has some potential for radiating stuff.
Yes, but they build quality is ok, so the tuning head normally doesn’t radiate. Actually the wiring could radiate a lot loss due the the fact it has two processors, such than only minimal amount of data has to be transmitted over this databus.
Lots of opportunities for radiation indeed, but strangely enough I experienced none though I gave it every chance with those long 0,50 mm2 copper wires.
As indicated before it can work fine, You see Jan’s got his unit working fine without noise as well. There must be something wrong with ChrisB’s installation or units. It is unfair to suggest that Trig has produced a poor product.
