Fw: [Elecraft] Interfacing K3 to TenTec

[Phil & Debbie Salas]

"...If the circuits in the amp have any delay, it can cause problems with 
the keying element lengths...."

Most of the big QSK amps use vacuum relays, which switch in typically 5-8ms 
(or faster with speed-up circuits).  Some of the newer solid-styate amps 
(THP and SPE) use high speed power relays that switch in less than 10ms.

I recently modified my ALS-600 to run QSK using inexpensive signal relays 
that switch in 5ms.   As part of this exercise, I looked at a number of 
radios to see what their "amp enable-to-RF output" delay was.  I measured my 
IC-706MKIIG and found it to be about 13ms.  An IC-7000 I had for a short 
time measured about 8ms.  New Kenwoods can be set for 10ms, and new TenTecs 
and Yaesus are 15ms.  And, of course the K3 is 8ms minimum.  So - virtually 
all current transceivers have a greater delay than the switching times of 
available QSK amplifiers.  I.e., there should be no problem directly keying 
the key line of the QSK amplifier with the radio - and especially with the 
K3 where you can increase the 8ms delay if needed.

Phil - AD5X