Icom radio issue

[ShawnR]

I purchased a 9A in January and am just starting to get to know it. Waiting for the field to thaw, then dry, a check ride, and now the annual is due, I have not flown it yet. But in familiarizing myself with it the other day, I noticed that when I keyed the mic, the ammeter dropped to 38 amps! This plane had 2 icom A200's in it at one time, but one had been removed due to a blown circuit board and was not repairable. I am suspecting this one is heading the same direction. I asked Icom about it and their reply was too much current (should be 2.6 amps on transmit) and no parts are available. No further info. I am thinking I am just going to order a new A220, but was curious if anyone has seen this. Is this an A200 issue? I would suspect an installation issue such as bad antenna connection but for the sake of a discussion, thought I might post this.

Working on the 4 with the awesome access to the rear of the panel, I am dreading yanking out the old mounts and wiring from underneath, but, it looks like that is the only way to work behind the 9 panel. Will be starting the annual this week so I will get to really familiarize my self with the 9.

Did some circuits in a friends 9 last week (right seat). Quite a bit different more responsive than a C172 ...eek....

 

[Walt]

My 2c, if you're going to replace the radio, the Garmin GTR200 would be the winner.

 

[Dugaru]

I am dreading yanking out the old mounts and wiring from underneath, but, it looks like that is the only way to work behind the 9 panel.

My slider 9A has this issue. A huge pain. It pays to spend some time figuring out the ergonomics before diving under there. Very helpful to have a second person to hand you things, and extract you if necessary!

I’ve told my family they should bury me in my 9A with my head stuck under the panel, because that will likely be what killed me.

Quite a bit different more responsive than a C172 ...eek....

True, but I don’t think you’ll have any real problems transitioning from a 172 to the 9. Just keep in mind two things: (1) you can actually overspeed the flaps (this is more of a theoretical problem in a 172) and (2) given its speed and relatively low weight, it’s capable of gaining altitude in cruise MUCH faster than a 172 or Cherokee.

 

[Avanza]

I purchased a 9A in January and am just starting to get to know it. Waiting for the field to thaw, then dry, a check ride, and now the annual is due, I have not flown it yet. But in familiarizing myself with it the other day, I noticed that when I keyed the mic, the ammeter dropped to 38 amps! This plane had 2 icom A200's in it at one time, but one had been removed due to a blown circuit board and was not repairable. I am suspecting this one is heading the same direction. I asked Icom about it and their reply was too much current (should be 2.6 amps on transmit) and no parts are available. No further info. I am thinking I am just going to order a new A220, but was curious if anyone has seen this. Is this an A200 issue? I would suspect an installation issue such as bad antenna connection but for the sake of a discussion, thought I might post this.

Working on the 4 with the awesome access to the rear of the panel, I am dreading yanking out the old mounts and wiring from underneath, but, it looks like that is the only way to work behind the 9 panel. Will be starting the annual this week so I will get to really familiarize my self with the 9.

Did some circuits in a friends 9 last week (right seat). Quite a bit different more responsive than a C172 ...eek....

The problem with high ammeter reading is related to the installation. I have seen this with other radios too.
When transmitting on the COM, there is a strong magnetic field around the RG400 antenna cable.
The ammeter has a shunt, creating a mV signal in proportion to the current.
It is important that the signal wire from the shunt has a shield, grounded in one end only.
Also there should be some distance between the signal wire and the antenna cable (RG400).

Good luck

 

[ShawnR]

Thanks Avanza. I was wondering if it could be an erroneous reading as the radio appears to work, although I have not checked for actual transmission. Just noticed this. I will check into those points.

 

[ShawnR]

My 2c, if you're going to replace the radio, the Garmin GTR200 would be the winner.

I am looking at that too. Thanks

 

[jklusman]

I am looking at that too. Thanks

I would appreciate hearing from those of you who experienced no problems replacing your Bendix/King KY-97A with an Icom IC-A200. Is it as easy as it appears to be using the MBA-3 adapter? I've done the search and am just looking for input from those of you who haven't had problems.
Thanks,
Jim K.
RV-8 driver

 

[ShawnR]

The recent post

The problem with high ammeter reading is related to the installation. I have seen this with other radios too.
When transmitting on the COM, there is a strong magnetic field around the RG400 antenna cable.
The ammeter has a shunt, creating a mV signal in proportion to the current.
It is important that the signal wire from the shunt has a shield, grounded in one end only.
Also there should be some distance between the signal wire and the antenna cable (RG400).

Good luck

Having finally flown the 9, I have no radio issues. I think that Avanza nailed it with his diagnosis. Looking under the panel, the current shunt is located very close to the radio wiring.

If I get to cleaning up some of the wiring, I am hoping to remove or relocate the runs and alleviate this issue.

Just an update.

 

[sahrens]

The recent post


Having finally flown the 9, I have no radio issues. I think that Avanza nailed it with his diagnosis. Looking under the panel, the current shunt is located very close to the radio wiring.

If I get to cleaning up some of the wiring, I am hoping to remove or relocate the runs and alleviate this issue.

Just an update.

I have three iCom 200s. I purchased them used as maintenance spares because I had two in my RV-7. I am building another airplane now and was thinking about installing them in my new build. I decided on iCom 220s instead as the 200 and 210 are interchangeable in the radio tray, but not with the 220.