Poor radio side tone

I have been flying with the original LightSpeed Zulu headset, still configured in mono from my previous plane, now in my SkyView equipped 12. Radio and sidetone has worked fine. I recently bought a new Zulu2 and the sidetone volume and quality dropped dramatically from the Zulu1. When swapping back the sidetone is improved but not to the previous level, (or I'm just more aware and sensitive to it since the new headset is so low). I recently configured both headsets for stereo and swapped back to try the Zulu2 and the sidetone is still of a low volume but now unreadable. Radio, intercom works perfect and everyone says my transmissions either way are clear. Any ideas? The AV5000A RV-12 control box has had previous problems but with the stall buzzer and been repaired by Vans. I don't have my plans at home but I know some of the potentiometers on that unit control outputs. I'm just not sure why switching to stereo makes it worse.

Radio?

Scott,
What radio is driving the new Zulu headsets?
It might be a matter of increasing the sidetone setting. The headset may simply need a bit more power. It is only miliwatts generally...

SV equipped RV-12 all have the Garmin GTR-200 com radio with built in stereo intercom. Sidetone appears to be linked to the Intercom volume and not directly adjustable. The fact that it is low in mono may be adjustable through the RV-12 control box and explained by different efficiencies between the headsets but being unreadable in stereo sounds like noise is being picked up somewhere in wiring. Unlike other RVs the wiring is all premade, basically plug and play with prescribed routings so there is little chance of a cold solder joint, bad connection or picking up signals from other avionics.

Question: when you first installed the GTR-200, did you write down the configuration settings that were in the unit? If so, are they the same or different?

Going into the configuration pages, you will find one for setting SIDETONE function and level.

In the past, I had an issue with SIDETONE level in my Garmin SL-30. It had been fine for several years but then it changed all on its own. My Garmin dealer stated that they have seen these units spontaneously change configuration values on their "own". They suspect power glitches as the culprit but have never been able to prove it.

scottmillhouse said:

SV equipped RV-12 all have the Garmin GTR-200 com radio with built in stereo intercom. Sidetone appears to be linked to the Intercom volume and not directly adjustable.

Click to expand...

Sidetone on the GTR-200 is adjustable in the Configuration Mode. With the radio turned off, press and hold the small knob and turn the radio on. Sidetone is under the Comm configuration.

Sidetone Dropping Out

I am currently fighting with my GTR 200 sidetone dropping after about 2 seconds of each transmission. It started out of the blue after about 15 trouble-free hours...new airplane. I've never had low volume problems, just the sidetone cutting out.

The Garmin tech told me to slave the sidetone volume to the the ICS, which I did, but that only fixed the problem for a couple of flights. Since then I've been lowering my mic gain from the default of 5 down to 4 to 3 and now 2, all to no avail.

Wished I'd written down my original parameters now.

Thought I should provide an update. Sidetone appears fixed now. I'm not sure why it drifted. It appears it was a coincidence with the new headset since both shared the problem.

Switched radio and headsets to stereo. Fixed by raising sidetone volume under configuration as other said and then lowering microphone gain by 1 but that ALSO raised intercom volume excessively so lowered that under the regular radio menu for all to match radio output volume.

Hello,

There is nothing tricky about setting up the Sidetone, MIC Gain, and other parameters on a GTR 200. The GTR 200 has a great display and user interface, and is very interactive, so you shouldn't be timid about making changes if needed. Just push in on the right knob as you turn the radio on with the left knob, and it enters CONFIG MODE.

Some have asked about the various settings and some have suggested needing to change parameters like the MIC Gain, so I did a quick test this morning with Zulu ANR headsets (original style) and the GTR 200 to explore this.

Sidetone Volume and MIC Gain Adjustments
The Sidetone volume is selectable from 0 to 10, with 5 being the factory setting. Notice that when you select 0, the display shows "SIDETONE ICS" which means that the sidetone volume is no longer set to a fixed value from 1 to 10, but instead is set to follow the current setting for intercom volume, which can even be changed in normal mode.

Please remember that Sidetone is what you hear only when transmitting on the COM radio and has nothing in common with intercom volume, unless it is set to be the same and follow intercom volume.

The MIC GAIN is selectable from 0 to 10, with 5 being the factory setting.

I found the factory settings for Sidetone volume (5) and MIC Gain (5) to work quite well and have always used these in my plane.

If you need a little extra help hearing the Sidetone, you can always increase it a little to something like 6 or 7, but you could also consider just setting it to ICS so it always follows the intercom volume.

I also varied the MIC Gain from 0 to 10 to see if I could find something I liked better than the factory setting of 5. I did not. Lowering the MIC Gain below 5 made the sidetone quieter (as expected) and increasing the gain above 5 not only increased the Sidetone volume, but also caused some increase in background noise picked up by the MIC, so again, I saw no improvement when changing the setting from 5.

Most users will never adjust the MIC Gain because their transmissions are clear and loud, but will instead adjust the Sidetone volume to their liking.

Personally, I am pretty picky about my Sidetone volume, but have always been able to "set it and forget it" with the GTR 200 since I almost always fly with the same headset. I find a Sidetone volume that is too loud to be distracting when transmitting, so that is about the only thing that will cause me to make a change.

I have always had a slight preference for a fixed Sidetone volume that sounds exactly the same each time I key the radio, but the GTR 200 also does a great job of providing Sidetone volume equal to intercom volume when the Sidetone volume is set to ICS, so I wouldn't hesitate to use or recommend that setting as well.

One other tip. Some headsets like the Zulu come with the dip switch set to mono, so you will want to check that before using with the stereo headset jacks in your RV. The mono configured headsets sound pretty lousy when plugged into a stereo jack.

Please let us know if you have questions about setting up your GTR 200.

Thanks,
Steve

Not sure if there was something else going on with my system since there was a sudden change. The Mic settings went down to 4 to eliminate the background noise being picked up. Linking the Sidetone and intercom together makes the Sidetone extremely loud in comparison so instead the Sidetone was raised from 5 to 7. Even though not linked with the intercom the intercom that was set at 75% by the menu was too high. Setting it down to 60% appears to have radio, sidetone and intercom volumes aligned. I should mention that I do have a slight hearing loss so my volume levels probably are higher than typically used. I know my passenger always set the headset volume control down about 1/2 way.