[Elecraft] K3 & Centurion Amp

[Jim Brown]

On 1/29/2014 7:38 PM, Michael Marx wrote:
> Thanks in a advance for any enlightenment anyone can give me

I've never seen a Centurion up close, but I own three Titan 425s and a 
Herc II, all of which I've used with the K3 (also K2, FT1000MP, and 
TS850). All combinations work fine, and I've done the hookup like you 
have, but it means that you can't use the rig's internal keyer.

So, I tried the standard hookup rather than Ten Tec's -- Key Out of the 
K3 drives PTT of the amp. This works fine, because all of these rigs 
have a delay in the range of 8 msec from when the Key Out signal keys 
the amp before RF is sent. This gives the T/R relay in the amp plenty of 
time to pull in, so no problem. There's a limit, though, on sending 
speed at which CW starts to get "choppy," as those 8 msec delays are 
subtracted from each dit and dah.

In my contesting experience, I start getting complaints at about 28 WPM, 
and I like to contest faster than that. The other factor is that more 
than once, I've had to stop in the middle of a contest because the 
vacuum relay in the amp was wearing out from too many cycles from QSK 
contesting. So -- I now do all of my high power contesting without QSK.  
Not ideal, and I really appreciate being able to run full QSK with the 
KPA500.

73, Jim K9YC