Static Electricity ?

[Brian]

A few days ago my UHF in the gyro went spastic making all sorts of noises before eventually being bad enough to have to turn it off [GME 3200]. We had to fly next day mustering and blokes coming so it was thinking cap on, first thought was to try grounding the frame of the gyro which I did. Rosie and I then re soldered the wires going from the helmet into the plug down to the push to talk and UHF thing and with a prayer or two the radio worked okay with only a few minore glitches.Now, still wondering about the possible build up of static electricity in the gyro, I had been doing quite a bit of flying over the last week in and around the rain. It had been really humid as well plus a odd bit of thunderstorm activity around to add to the mix.Has anyone any infomrmation in regard to gyro static electricity ?? It seems that around every 18 months I seem to replace the UHF with a new one and of course, I take the offending radio into a very competent repair place with the same answer every time. " Nothing found wrong" !! ??? and you get it home, stick it on the house set up and away it goes just dandy

[bones]

Nothing wrong with the 3100, i got 3 i think now, hooked up with VHF"s, work just as good as the 3200, only half the size.pinched this off another site that i typed up the other day might be helpful to your situation;"Save yourself the trouble, go to your nearest "dick smith" type store, somewhere that works with computers, and buy a bout 5 Ferrite(sp) resistors, these are the black lumps on all your computer cables, should cost about $2 each, put them on every wire in and out of the radio, they just clip around the wires,,, should be problem fixed.Took me about 18 months of taking radios out sending them away, only to be told nothing wrong with them, i was having massive mic feed back, the easiest cheapest fix i ever did find, i put them on every radio i fit now, even they dont need them."This guy was have noise problems with a uhf same as i did.Static electricity shouldnt be able to build up as i understand it, but anything is possible i guess, more likely the problem is starting with your motor get the right motor back there and no more problems

[birdy]

Static elect is a dry air thing, not stormy humid air.I git alot ere, for obvious reasons, but it never upsets the radio. just wakes me up wen i "ground" after a few hours airtime.One thing iv found that caused alota head hurts was the earth " shield" in the skidlid lead. It freys very quickly coz its pi22weak material, and causes intermitant hell on comms. [ usualy wen yardn up ]Iv had the same ol Sundowner uhf i started with, 15 years ago.Its been rained on, cooked and crashed more times n i care to remember, but it just keeps on workn. Any probs iv had are always in the head set.

[Brian]

Thanks Bones & Birdy. I will get some of those ferrite resistors first trip to town. The old gyro had a Sundowner and it worked really well but then someone reckoned the GME was the go etc etc, the first of them worked really well but for the last ......years, I have had lots of trouble getting any range out of them despite buying new antennas and and making sure the coax plug was soldered correctly [i] and I have had ground crew pull up alongside my gyro and they have been able to recieve on handhelds and my crash hot GME didnt even break the squelch

[aussie_paul]

"ferrite resistors"FWIW, I think the correct terminology is Ferrite Cores.Interesting info, http://www.ferroxcube.com/appl/info/sfemisup.pdfAussie Paul.

[chook]

Paul is correct - "they is ferrite cores" and thanks for that interesting attachment. Geez Chopper - hard to form an opinion with with such accurate symptom descriptions. "went spastic".Are we talking cracks and pops or high pitched squeals and are you hearing that in the headset. If you move things like the plug, the wiring coming out of the plug, the wiring going into your headset (Birdy"s problem) can recreate the symptoms. Is the motor running? Does it happen with the motor off?And while the ferrite cores MAY fix the symptoms they generally hide bad design or other faults.I am intrigued by the fact that a new unit usually cures the problem. This would indicate that the problem is external to the radio but is upsetting the radios suppression cct. This is usually a couple of small capacitors and a choke (small coil wound on a ferrite core) in the incoming power cct within the radio and would be difficult to check unless the "radio guy" specifically injected noise accross your power cct input and was aware of the rejection specifications.I have had some experience with the GME TX3200 and had to replace the modular plug (6pin RJ12) because of corrosion as this particular aircraft operates from the coast. Get Rosie (she sounds like an excellent acquisition) to look with a torch into that plug receptical and on the fine pins of the plug itself - a quick wipe with some meths wont hurt it either. These radios are usually interfaced "some how" into the various headsets, mics and boxes that the guys use and that is where it usually comes unstuck. Generally keep all of the leads short and don"t rely on the frame for your earth return on the power run.If all else fails - just bring the whole Bl00dy

[GraemeMonro]

I got some spare ferrrite"s if it"s any help, what colour would you like?Graeme.

[Brian]

Paul is correct - "they is ferrite cores" and thanks for that interesting attachment. Geez Chopper - hard to form an opinion with with such accurate symptom descriptions. "went spastic".Are we talking cracks and pops or high pitched squeals and are you hearing that in the headset. If you move things like the plug, the wiring coming out of the plug, the wiring going into your headset (Birdy"s problem) can recreate the symptoms. Is the motor running? Does it happen with the motor off?And while the ferrite cores MAY fix the symptoms they generally hide bad design or other faults.I am intrigued by the fact that a new unit usually cures the problem. This would indicate that the problem is external to the radio but is upsetting the radios suppression cct. This is usually a couple of small capacitors and a choke (small coil wound on a ferrite core) in the incoming power cct within the radio and would be difficult to check unless the "radio guy" specifically injected noise accross your power cct input and was aware of the rejection specifications.I have had some experience with the GME TX3200 and had to replace the modular plug (6pin RJ12) because of corrosion as this particular aircraft operates from the coast. Get Rosie (she sounds like an excellent acquisition) to look with a torch into that plug receptical and on the fine pins of the plug itself - a quick wipe with some meths wont hurt it either. These radios are usually interfaced "some how" into the various headsets, mics and boxes that the guys use and that is where it usually comes unstuck. Generally keep all of the leads short and don"t rely on the frame for your earth return on the power run.If all else fails - just bring the whole Bl00dy

[aussie_paul]

"going spastic"Just love those technical terms Brian!!!!Aussie Paul.

[Greg Mitchell]

I got some spare ferrrite"s if it"s any help, what colour would you like?Graeme.Ha Ha Ha Ha Ha......

[gbw]

"Took the helmet in to Rosie and we re soldered the wires going into the 5 pin plug"Talking to an oldschool refrigeration mechanic today (ie he repairs rather than replaces)He gave me some "silicon wire" It is multistrand stainless steel wire with a silicon wrapping. Reckons it never breaks and conducts better than copper. Great for places with a lot of vibration. I had not heard of it before, and just passing it on.Graham

[Mark Horan]

Id say "going spastic" was the correct technical term!Mark

[Brian]

"Took the helmet in to Rosie and we re soldered the wires going into the 5 pin plug"Talking to an oldschool refrigeration mechanic today (ie he repairs rather than replaces)He gave me some "silicon wire" It is multistrand stainless steel wire with a silicon wrapping. Reckons it never breaks and conducts better than copper. Great for places with a lot of vibration. I had not heard of it before, and just passing it on.GrahamThanks Graham, woth looking into. Lots more help than flamin ferrits ............

[Brian]

I have another type of aerial to try as well will get this rig functioning correctly yet !!

[chook]

Chopper can you post a photo or 2 so that I can have a look at your 5 pin plug?Regards......Chook.