ICOM IC-A200 Volume Adjustment

[EdFred]

No, not from the front side, anyone can do that. But when it is barely turned on it is LOUD LOUD LOUD. There's a couple holes covered with stickers on the top of the unit labeled S-TONE, MIC, and SQL (squelch). Looking inside, and after taking my old one apart, they are just some phillips type set thumb screws. Anyone know what adjustments to make?

 

[ScottM]

No, not from the front side, anyone can do that. But when it is barely turned on it is LOUD LOUD LOUD. There's a couple holes covered with stickers on the top of the unit labeled S-TONE, MIC, and SQL (squelch). Looking inside, and after taking my old one apart, they are just some phillips type set thumb screws. Anyone know what adjustments to make?

I went looking for a service manual but only found ones for sale. I did look through the user manual and saw nothing. S-TONE would be side tone and that is not the received audio but a little of the transmit audio that is sent out for you to hear while you are talking. Have you checked the audio panel settings?

 

[EdFred]

I went looking for a service manual but only found ones for sale. I did look through the user manual and saw nothing. S-TONE would be side tone and that is not the received audio but a little of the transmit audio that is sent out for you to hear while you are talking. Have you checked the audio panel settings?

I pulled the 340 audio panel, but there is nothing able to be set from the outside, and I am not taking that apart . It's not just the side tone on the ICOM, but all volume. The unit turns on with the volume knob in about the 7:30 position, and max volume is about the 4:30 position, with the adjustment range being a clockwise rotation. It is LOUD at the 9:00 position, which gives me no adjustment range. Maybe I'll pull it on Saturday and just tweak with those thumb screws and do radio checks with the FBO. I imagine I just have to turn em a little bit one direction, but thought I would ask here first.

 

[ScottM]

I pulled the 340 audio panel, but there is nothing able to be set from the outside, and I am not taking that apart . It's not just the side tone on the ICOM, but all volume. The unit turns on with the volume knob in about the 7:30 position, and max volume is about the 4:30 position, with the adjustment range being a clockwise rotation. It is LOUD at the 9:00 position, which gives me no adjustment range. Maybe I'll pull it on Saturday and just tweak with those thumb screws and do radio checks with the FBO. I imagine I just have to turn em a little bit one direction, but thought I would ask here first.

But like I said NONE of those labels on those taped over holes indicate an adjustment to the received audio. One is the squelch level adjustment, anothers is for the microphone gain, and the third is for side tone. Side tone is for transmitted audio that is fed into the speaking person receive path to help them to understand what they are saying. We are all used to hearing ourselves speak but with headphones on that is tough so the radio employs side tone to make the transmit experience more comfortable. I really doubt it is at the root of your problem.

I am thinking there may be an impedance mismatch between your audio panel and the radio as a potential problem. The other thing I was lookign for was an audio out adjustment that you get into via a test mode and then set a register from the front panel of the radio. Taht is why I was hunting for the manual.

 

[ScottM]

Found this for the A200

[SIZE=+1]Audio output: 5 W into 4 ohm load, (100 mW out at 500 ohm load for audio panel)[/SIZE]

[SIZE=+1]

Your Garmin panel is for a 500 ohm input Z.

I think that your A200 is set up for the 4ohm 5 Watt output going into your audio panel headset input. This would explain your lack of granularity in the volume level.

Now we just have to figure out how that is selected. Is it something that is changeable or is it a different output pin?

It looks like there are two ouputs; Pin H on the A-200 is the output pin for headset audio that should be the one that goes to your audio panel. Pin E is the high level audio that should go to your speaker.

Here is a link to the wiring diagram for your radio. http://www.aeroelectric.com/Installation_Data/IC-A200_Icom_Installation_Wiring.pdf


[/SIZE]

 

[gismo]

No, not from the front side, anyone can do that. But when it is barely turned on it is LOUD LOUD LOUD. There's a couple holes covered with stickers on the top of the unit labeled S-TONE, MIC, and SQL (squelch). Looking inside, and after taking my old one apart, they are just some phillips type set thumb screws. Anyone know what adjustments to make?

If you don't already know, S-TONE is sidetone (hear yourself when transmitting), MIC is the transmit modulation level (don't mess with that), and SQL is a squelch adjustment (mute the audio when the received signal is too noisy).

I'm wondering why your's is so loud, the one I tried in the store sounded normal. Some headsets have a volume control on them, does yours?

I really doubt that there's an internal volume control adjustment but you might try calling Icom support and asking. Is there any chance you are plugged into a speaker jack instead of a phones jack?

http://www.icomamerica.com/

 

[EdFred]

OK, here's what I did. I had an ICOM IC-A200 and the radio started to die. So, I bought a replacement one, took the old one out, put the new one in and the volume difference was HUGE. On the old one (even when it was working) I would have the volume set on the front panel to about, oh the 11-11:30 position, and give me some volume adjustment. The new one is alarmingly loud even in the 9 o clock position. My headphones are plugged into the same spot, my GNS430 volume is in the same spot, and the ICOM radio is in the same tray as the old one, but the volume is WAAAAAAAAAY high. I will double check to see if it is just the side tone, or all volume.

 

[ScottM]

OK, here's what I did. I had an ICOM IC-A200 and the radio started to die. So, I bought a replacement one, took the old one out, put the new one in and the volume difference was HUGE. On the old one (even when it was working) I would have the volume set on the front panel to about, oh the 11-11:30 position, and give me some volume adjustment. The new one is alarmingly loud even in the 9 o clock position. My headphones are plugged into the same spot, my GNS430 volume is in the same spot, and the ICOM radio is in the same tray as the old one, but the volume is WAAAAAAAAAY high. I will double check to see if it is just the side tone, or all volume.

I cannot find a service manual anywhere on the web, tha tis unless I want to buy one. I cannot even find a hack for a register to change the audio output. You have two safe choices. First see if there is a service manual that you can borrow form the avionics shop or two call Icom and see if they will tell you how to adjust it.

 

[Ken Ibold]

OK, here's what I did. I had an ICOM IC-A200 and the radio started to die. So, I bought a replacement one, took the old one out, put the new one in and the volume difference was HUGE. On the old one (even when it was working) I would have the volume set on the front panel to about, oh the 11-11:30 position, and give me some volume adjustment. The new one is alarmingly loud even in the 9 o clock position. My headphones are plugged into the same spot, my GNS430 volume is in the same spot, and the ICOM radio is in the same tray as the old one, but the volume is WAAAAAAAAAY high. I will double check to see if it is just the side tone, or all volume.

Jeez, I'll trade radios with you. My Icom IC-A200 is so quiet I have it on max volume and the headset on max volume and it's barely audible during initial climb. And in mine, it's not sidetone, it's receiver volume, independent of whether the intercom is turned off or on (and on max volume as well).

 

[EdFred]

I talked to ICOM, counterclockwise adjustment on the potentiometers under the foil tape will reduce the side tone, mic gain, and squelch. Clockwise increases them. So I guess tomorrow or Saturday I will clog the airwaves with "radio check" problem is, I only need to near myself. People are gonna love that. Is there a ground test frequency that can be used?

 

[gismo]

I talked to ICOM, counterclockwise adjustment on the potentiometers under the foil tape will reduce the side tone, mic gain, and squelch. Clockwise increases them. So I guess tomorrow or Saturday I will clog the airwaves with "radio check" problem is, I only need to near myself. People are gonna love that. Is there a ground test frequency that can be used?

So your problem is sidetone. IE you hear yourself too loud when transmitting? A dummy load instead of the antenna would let you play with that without bothering anyone. For that you need a 50 ohm 5 watt carbon resistor on a BNC. I wouldn't mess with the mic control unless you have access to the right test equipment as this will affect modulation and splatter (interference with adjacent channels) and AFaIK you are legal to change that without an FCC license.

 

[EdFred]

I'm guessing it is just a side tone issue. I will test it when I get out there. I *thought* Rx was also loud, and if that's the case, I dunno.

 

[gismo]

I'm guessing it is just a side tone issue. I will test it when I get out there. I *thought* Rx was also loud, and if that's the case, I dunno.

One thought I had was that the speaker and headphone outputs were crossed up going to the audio panel but that's not consistent with the problem occuring when you just slid a different radio into the already wired tray. Might be worth seeing if the speaker audio works normally though (there will be no sidetone there).

 

[EdFred]

I suppose I could Tx on my 430, monitor on my ICOM, and see what happens. Turning the 430 volume all the way down of course.

 

[ScottM]

How did it go? Wile I doubt the s-tone will do anything for your recevie audio problem I am still curious

I cannot find a service manual online to see if there is anything else that could be done. If you have not got it solved you could bring it to a service shop or just ask one of the techs there if he has an idea.

 

[Steve]

http://www.aosc.org/air760ch.html

best fit - 121.600 - 121.925 Airport Utility and ELT Test

or possibly - 122.775 Aviational Instruction and Support

I talked to ICOM, counterclockwise adjustment on the potentiometers under the foil tape will reduce the side tone, mic gain, and squelch. Clockwise increases them. So I guess tomorrow or Saturday I will clog the airwaves with "radio check" problem is, I only need to near myself. People are gonna love that. Is there a ground test frequency that can be used?

 

[EdFred]

Turns out the volume is louder than the other radio - but the VERY LOUD was just the side tone. I made one adjustment on it and got it to go down some, am flying again tonight, so I will adjust it again. I'm just using the CTAF right now.

 

[ScottM]

Turns out the volume is louder than the other radio - but the VERY LOUD was just the side tone. I made one adjustment on it and got it to go down some, am flying again tonight, so I will adjust it again. I'm just using the CTAF right now.

If it is just the sidetone then that S.Tone adjustment should be all you need.