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Icom IC-A220 moisture issue

Bender

Registered User
Installed a new Icom IC-A220 last fall and have had zero issues with it until this past week. Took a trip to Idaho and, as usual, everything was damp in the mornings from the heavy dew. Every morning the radio failed to transmit. After 10ish minutes of flying with the vents open and heater on, the transmitter worked flawlessly until the next morning. Wash, rinse, repeat x3. Got back to Texas last night. Fired up the plane today and radio works perfectly. Called Icom and they just said that it was impossible to troubleshoot without being here. Radio is under warranty until July 2021 but I’m sure if I send it to them it’s going to work flawlessly on their test bench. Has anyone else had this issue? Any suggestions besides selling this thing on ebay and buying a Garmin?


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Does the transmit light come on when you push the ptt switch? If not you have a switch/wire issue


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Ptt is going through a newer Sigtronics SCI-S. Just as I finished typing the original post, I received this from Icom,


Email (Rick) (06/26/2020 04:02 PM)
Greetings Travis,

Thank you for contacting Icom America.

There have been no reported moisture related issues such as you describe.
The clue here is the use of the SCI-4 which is known to not take the radio key line to a hard ground which can cause the radio not to TX at times.
Please reference the following Sigtronics link, the Instructions section "Radio Keyline Modification."
https://www.sigtronics.com/air/sci.html
Click here for information regarding Warranty Registration, Service/Repair Authorization form, Knowledge Base & Technical Support: http://www.icomamerica.com/en/support/default.aspx

Note: Mention of third party products or services is provided for customer convenience and does not imply an endorsement or quality assurance by ICOM America.

Sincerely,
Rick
Technical Support Representative
Icom America, Inc.
12421 Willows Road NE
Kirkland, WA 98034


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Tested ptt switch during malfunction. Ptt switch checks good. During malfunction, green light on the intercom lights up when ptt is depressed. Pilot side is already wired via the “alternate” method in the SCI keyline modification instruction.


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Tested ptt switch during malfunction. Ptt switch checks good. During malfunction, green light on the intercom lights up when ptt is depressed. Pilot side is already wired via the “alternate” method in the SCI keyline modification instruction.


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Lack of common ground then..


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look up which pin the PTT grounds at radio connector, ground it... and se if TX light goes on, that will rule out a radio problem... as I assume is the case...
 
Do you have the emergency jacks installed? Are your mic and audio jacks grounded to the airframe or are they mounted with isolation washers? Did you verify operations as per the modification instructions? I.e, did you short the emergency ptt (hand mic ptt) to ground when the pilot's ptt was inop?

Web
 
Emergency jacks are not installed. The jacks don’t have isolation washers. It appears that they only ground via the barrel contacting the back of the panel. Have tested multiple times today and no failures. I did not try shorting the hand mic ptt to ground, but if the issue pops up again I will. I suspect that everything will be fine until I return to Idaho next June.


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Mike, it's almost certainly a moisture issue - somewhere? - in the system. FWIW, I was there, including right-seating with Bender. We shorted across the ptt switch, same result. Maybe the intercom, maybe the radio, seems to be a some sort of conduction or maybe ground loop issue when moisture is present????
 
Mike, it's almost certainly a moisture issue - somewhere? - in the system. FWIW, I was there, including right-seating with Bender. We shorted across the ptt switch, same result. Maybe the intercom, maybe the radio, seems to be a some sort of conduction or maybe ground loop issue when moisture is present????

nope... ground loop is a totally different critter...

Moisture , nope!

it's a stupid simple switch... if you GROUND the PTT wire AT the radio the radio WILL go into transmit mode, and since he says it doesn't , THEN YOU ARE NOT GROUNDING THE PTT at the RADIO!!

so it's a wire issue in the PTT switch/wire or the intercom......
 
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Without being my usual sarcastic self (Sigtronics and Icom connected together?!). Sorry

Huge red flag with the jacks grounded to the airframe. Even the installation instructions from Sig say to bring a ground wire back to a 'central avionics ground'. Which also means that the jacks can (should) be on isolation washers. Right now, when you press your ptt switch, the ground path for that circuit has to go through a bunch of seams and painted surfaces to get to true ground.

Not having emergency jacks is also a problem. Right now, with e jacks, you could plug in a ptt switch or hand mic and see if the radio transmits without the intercom being in the system. AND, if it does, keep working the radio until the problem is resolved.

If you stay with the Sig, make sure the jacks, the intercom, and the radio are all grounded to the same ground stud.

Web
 
Thank you for the replies. Ordered the right washers per the sigtronics manual. Will ground the jacks back to the point where the radio and intercom are grounded. Emergency jack will be going in as well.


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....... if you GROUND the PTT wire AT the radio the radio WILL go into transmit mode, and since he says it doesn't , THEN YOU ARE NOT GROUNDING THE PTT at the RADIO!! ....

There are very few absolutes in life.
I doubt this is one of them.
If there's some sort of problem internal to the radio,
then the external switch & wiring could be fine.
 
For anyone needing isolation washers:

Switchcraft brand, part numbers S1028 and S1029. One has a shoulder that fits into a 7/16" hole. the other fits over the jack threads from the other side of the hole. Together they prevent the jack from contacting a conductive surface.

Web
 
Keep us updated on what you find with your radio. I purchased a reconditioned A220 that is doing the same thing as yours is. I find it hard to believe that it is a grounding issue when the A210 that it is replacing didn’t have the same problem.
What model of Garmin radios are any of you having good results with?


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That line of Icom radios was made to replace the KY-97A. And after the -A200, -A210, and A220, the KY-97A continues to be built and sells well. Hmmm. . . .

Any of the smaller Garmins work well and they work well with other brands of equipment such as intercoms. I like the GTR-225 better than the GTR 200.

Web
 
Just for reference, I purchased my intercom new and had it professionally installed in 2013. I need a 4-place intercom or else I would just use the internal intercom on the 220. Previous radio was an old Narco NCS-812. Never had any issues for 6 years. Haven’t had any issues with the 220 until this trip. In the early morning in Johnson Creek, there was so much moisture on the inside and out of all the windows that it was impossible to remove. The only way that I’ve found to clear it up is to get the plane running to move some air over it and get the defrosters going. This plane has been to JC multiple times in June with similar environmentals and never had an issue with the old Narco. Nothing was changed with regards to the intercom during the radio swap. Still waiting on parts to arrive to fix the jacks, but everything is working fine now so it’ll be hard to tell if that was the culprit.


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For Supercub installations, remember that there's a pop-up air vent on many, just in front of the windscreen. My L-21B had a Narco Com 810 and transponder in a console under the panel. The air vent is also an efficient rain scoop, as I found out on the way back from KC in light rain most of the way. Fortunately, one area avionics shop had a crusty old bench technician who knew how to work on those things, but water stains on the tray and case never went away. This could be a problem when tied outside with any precipitation. Thereafter, I taped off the vent edges with Scotch 35 electric tape (yellow). Minimal adhesive residue, and was able to pop the vent up a couple times when I forgot to take the tape off before flight. A bit of thread drift, but relevant to moisture issues.

Thanks. cubscout
 
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