[Boatanchors] TCS Tx & Rx ... CORRECTED

[Bill Cromwell]

Hi John,

We may just have to agree to disagree. I wondered if my own 'figgerin'
was off somehow on that timing arithmetic. I have been wrong before - at
least a couple of times. So I went and looked it up. Your basic
'assumptions' about characters per second are quite a way off and even
very long for the basic 5 words per minute speed. My references are the
ARRL Handbooks. You did the arithmetic okay but apparently started with
the wrong numbers.

I handled CW traffic for a while on QMN (the Michigan CW traffic net)
and my traffic speeds reached around 40 WPM in my heyday. During that
period I had to use a keying relay in two different transmitters at
different times. The inductive spike ate the keying transistors in my
electronic keyers of that day. The diode cured that problem. The keying
timing did NOT change. That is from hard experience. And it supports the
math from the handbooks.

There are uses for the RC network at the key to suppress the sparks that
may occur there - especially if B+ is keyed. The sparks can cause RFI at
great distances. Some hams apparently reported the spark modulating the
transmitter - a definite no-no. RC networks added to the a relay coil
become RCL networks. I would expect more moderation of the relay timing
from that. Apparently it also doesn't have enough effect to change the
morse timing, either. I have not tried that as the problem I had was
preserving keying transistors from the inductive spike.

One specific keyer was the "Accu-Keyer" which was designed for
transmitters that key by pulling ~12 volts positive DC to ground. You
can't plug that into a transmitter with grid block keying. You don't
even have to touch the key..the output transistor will die immediately.
Thus the relay. And the new problem - the spike. Followed by the diode
which cured that problem.

73,

Bill  KU8H