[Icom] Need info for IC-746, IC-756 zero-beating FAQ

[Clifford, Rick]

ICOMer's,

Happy New Year from KF6UEB in Irvine, CA, USA.

I am a happy owner of an IC-746 (yes, just the plain old model). I've been
asked to compile some information in the form of FAQ to de-mystify the
process of zero-beating the IC-746 and IC-756 models.

Rather than just describe the two processes I am aware of for the IC-746
(adjust frequency until pitch of received signal matches sidetone, or adjust
frequency until pitch of received signal in CW mode is same as pitch in CW-R
mode), I would like to dig a little deeper into the whole process of CW
signal generation and reception with these rigs.

I'd like to start a correspondence with anyone who has knowledge of the
IC-746 and IC-756 internals associated with CW signal transmission and
reception. For example:

What mixing steps are involved from inital RF reception to generation of CW
audio, and what are the local oscillators (e.g., IF and BFO) used as part of
these processes?
Is it true that some of the transmitter stages are running continuously in
CW mode, and that only the power amplifiers are keyed on and off?
What signals are used to generate the side-tone? Is the transmitter signal
used as part of side-tone generation?
What does the CW Pitch control adjust to cause the pitch of the received
signal to change?
What is difference between the CW and CW-R mode? From a technical/signal
processing perspective, what is changing when I switch from CW to CW-R?

Please contact me directly at rick.clifford@eds.com.

BTW, I've asked ICOM for some answers (via e-mail) but have not heard back
from them.

TNX ES 73,

Rick