Sidetone Adjustment
The MS-2002 uses full-duplex audio (the same as a conventional telephone line) where the talk and listen audio are sent and received on the same line. When you talk on a channel, you also hear your own voice back in the speaker or headphones. This is called sidetone. If you are using the MS-2002 with a microphone and speaker, sidetone could cause unwanted feedback, since the microphone may pick up your returned voice audio and reamplify it. This could also happen if you are using a headset when the ear cushions do not completely cover the ears, although it is probably much less likely. In either of these cases, you should minimize the amount of sidetone. On the other hand, if you are using headphones that completely enclose the ears, a certain amount of your own voice level is desirable to overcome the muffled sensation when talking. See Figure 8 on page 10, for the adjustment locations.
If you are using a speaker and microphone, or open-ear style headphones, adjust the sidetone as follows:
1.Simultaneously press the All Talk and PA keys to activate the test tone.
2.Tap the channel 1 Call key to send the test tone on channel 1.
3.Increase the volume until you can hear the test tone.
4.Using a small, flat-bladed screwdriver, adjust the channel 1 sidetone through the access hole in the bottom of the MS-2002 (Figure 8) to minimize the tone volume.
5.Tap the channel 1 Call key to turn off the test tone on channel 1 when finished.
6.Tap the channel 2 Call key, and repeat the adjustment for channel 2 sidetone.
7.Tap any other key, except a Call key, to turn off the test tone when finished.
If you are using headphones that completely enclose the ears, adjust the sidetone as follows:
1.Tap the Headset key to turn the headset microphone on.
2.Tap the channel 1 Talk key to turn it on.
3.While speaking into the microphone and using a small flat-blade screwdriver, adjust the channel 1 sidetone so you hear your voice at an acceptable level in the headphones.
4.Tap the channel 1 Talk key to turn it off when finished.
5.Tap the channel 2 Talk key to turn it on.
6.Adjust the channel 2 sidetone as for channel 1.
7.Tap the channel 2 Talk key to turn it off when finished.
FIGURE 8. MS-2002 Bottom View