[Boatanchors] keying

[Glen Zook]

Well over 5-decades ago, like in late 1959, when I upgraded from Novice Class to General Class, I had a Globe Chief 90A transmitter with a WRL-755 VFO and used a TR-switch with a 6AH6 instead of an antenna change over relay.  Since I wanted to operate full break in on CW I came up with a solution that involved a relay.  The relay had a low voltage coil and 2-sets of normally open contacts.  One set of contacts was bent so that they made contact before the other set and remained closed longer.  The contacts that closed first, and released last, were used to key the VFO and the other set keyed the transmitter.  The low voltage for the relay coil was then operated by my then Vibroplex Champion.  This arrangement was definitely not quiet!  However, this system did produce a chirp free signal.  Since my station was in the basement, the additional noise did not bother anyone!

It would be possible to accomplish this today with reed relays or even make it solid state using transistors to do the keying.
 
Glen, K9STH


Website:  http://k9sth.com


________________________________
 From: Rob Atkinson <ranchorobbo at gmail.com>
To: Charles Ring <w3nu at roadrunner.com> 
Cc: Boatanchors Mail List <boatanchors at mailman.qth.net>; johnson at mailman.qth.net 
Sent: Sunday, March 17, 2013 2:28 PM
Subject: Re: [Boatanchors] keying
 
You have to let the VFO free run while you transmit.  Don't key it;
key the transmitter.  The manual for the HA-1 TO Keyer has
instructions and charts for constructing a simple RC combination on
the rear panel octal jack (you wire the cap and resistor to the octal
plug that connects the line between the keyer and the rig) so the
keyer will handle the particular keying v. and current you have.  The
purpose is to simply prevent long term damage to the P&B wetted relay
contacts.

You'll have to experiment with small pie chokes, resistors, and
capacitors in series with and across the hot to ground keying line to
see what is effective at reducing the spark both on make and break.
It is helpful to see the keying envelope on a scope and have a friend
a mile or two away tune around listening for clicks.  There are two
kinds of clicks--those that are only in the shack from the key
contacts and the ones that travel a long distance due to a vertical
rise and cutoff of the keying envelope.  I put a 4 mfd 600 v. oil cap
between the cathode and ground on the 807 to give a nice keying
envelope shape because I got complaints of key clicks.   I
experimented with various values looking at the keying envelope on a
scope and found that 4 or 5 uF did the job.  If I recall correctly, I
also put a 2 watt 10 or 20 ohm resistor in series with the hot contact
on the key.