[Elecraft] K3 - qsk keying loop

[Vic K2VCO]

Barry N1EU wrote:
> K7GT obviously has the same concerns.  Over the past decade I've used
> a slew of Ten-Tec and Yaesu xcvrs interfaced to Ten-Tec, Alpha, and
> Acom amplifiers via plug 'n play keying loops with uniformly excellent
> performance.

There is a delay built into the K3's amplifier keying output, both 
before RF is produced and after it stops. Perhaps all Elecraft needs to 
do is publish this specification and it will be possible for you to feel 
more comfortable. I have used the K2, which has about 15 ms pre-RF delay 
  and adjustable after-RF hold with homebrew and modified amplifiers 
that use vacuum relays as well as an Alpha with PIN diodes, and in all 
cases there has been no hot switching (checked with a scope).

The K3's "semi-QSK" setting allows you to adjust the hold time from the 
same as "full QSK" to a much longer delay than you will need. So as long 
as the pre-RF delay is long enough, you should have no problems.

In my opinion, keying loops add unnecessary complication.
-- 
73,
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco