Icom IC-740

Settable sidetone level

IC-740 has one control that makes very little sense to me: TONE. Is there any reason to fiddle with it when listening to CW or SSB? Not really.
On the contrary IC-740 is badly missing another control: CW side tone level. The only way how to set the level is to remove the top cover, find the proper trimmer and rotate with it. Will you do that when finding the level is improper just in the middle of a CW contest?

I used the TONE potentiometer for that purpose. The CW sidetone can be adjusted easily at any moment. It is also independent on AF knob position. The main change is on the VR-A board. Look at the images below.
The 800 Hz side tone is taken from the MAIN board which is described elsewhere.

VR-A board from the top..

VR-A board from bottom. A few parts had to be solder from this side.

Schematics of the change.

Parts layout on the VR-A board, top view.


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