[Elecraft] something is bugging me, K2 keying problem.

[Geoffrey Mackenzie-Kennedy]

 A pair of cross coupled NAND gates as a 'switch debouncer' should be 
useful?

Geoff
GM4ESD

----- Original Message ----- 
From: "Don Wilhelm" <w3fpr at earthlink.net>
To: <N5BZ+ecr at chem.lsu.edu>; <elecraft at mailman.qth.net>
Sent: Thursday, January 04, 2007 2:54 PM
Subject: RE: [Elecraft] something is bugging me, K2 keying problem.


>I may be proven wrong someday, but I believe that 'problem' is caused by
> contact bounce at the key (or bug).  Cleaning the contacts may not be
> sufficient, and it will vary from keying device to keying device depending
> on the type and condition of the surfaces at the contact area.
>
> I cling to my contact bounce theory because it rarely occurs if the diodes
> are connected to a computer output.
>
> I have heard that a tiny drop of NoOxIt or similar product on the contacts
> helps, but I have not tried it myself.
>
> One idea (although it makes things more complicated) is to key a mercury
> wetted reed relay (if you can find one) with the bug and drive the diodes
> with the relay contacts.  The mercury wetted contacts do not bounce (well,
> they could but it is greatly reduced).  The other thing that works is to 
> use
> an external keyer (I use the K1EL K12 keyer) which has a separate input
> wired for the hand key.