[Elecraft] K3 Variable amp keying delay >>not long enough!!??

[Vic K2VCO]

Ian White GM3SEK wrote:

> That is correct. Attempting to switch 120V AC will damage the K3, and an 
> intermediate relay will add even more delay.

<snip>

> Amplifiers that require high-voltage, AC or negative switching are 30 
> years behind the times. If the owner wishes to use the amplifier with a 
> modern transceiver, I think it's clearly his responsibility to bring the 
> switching interface up to date. Every design is different, but 
> modifications are out there on the web, and none of them should take 
> more than an evening's work.

I agree. One simple modification that you can make without changing the 
relay is to provide a 28-30 volt DC source in the amplifier. This will 
operate a 120 volt AC relay reliably (and may make it quieter, too).

The K3's switching circuit will handle 30vdc easily. Of course, you 
still have to determine the delay needed.
-- 
73,
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco