[GreenKeys] The best TU?

[Jim Haynes]

All this discussion is fairly entertaining, but I would not consider it
seriously informative.

Which TU works best on very weak signals in noise?

Which TU works best on signals that are flat fading into the noise?

Which TU works best on signals affected by frequency-selective fading?

Which TU works best on signals affected by mutipath echoes?

Which TU works best in situations of strong interference, such as
experienced in a contest?

Which TU works better with sending from tape or sending with diddle,
and which works better on hand sending with possibly long pauses between
characters?

And then, with any of these conditions, which TU works best at 170 Hz
shift, and which works best at 850 Hz shift?

Then many of the TUs have multiple modes: limiter on and off, ATC/DTC,
linear discriminator or peaked discriminator, and others, so which set of
modes works best for all the above considerations?

If you are running the output of a TU straight into a TTY machine it is
hard to get a fair comparison.  The reason is that a false start or a
mutilated stop pulse will usually cause several erroneous characters
to be printed before the system recovers.  You need to be using an
electronic regenerator to trap these conditions so that the machine(s)
always see clean signals.

Jim W6JVE