[Elecraft] K3 - amp and tuner question

[Fred Jensen]

On 12/8/2012 1:42 PM, Bill Clarke wrote:
> Do I have this right:

Well ... maybe.

> The K3 works seamlessly with the KPA500 for band selections?
> Band changes are done without operator input?

Correct.  You can change bands on the K3 and the KPA500 will follow, or 
you can push one of the band buttons on the KPA500 and the K3 follows. 
This is true however, *only* if you have the two connected via the DB15 
interface cable from Elecraft.
>
> Add the KAT500 to the chain and all tuning is automatic - without
> operator intervention?

Not exactly ... at first.  The KAT500 "remembers" the settings for each 
segment in each band, for each antenna, just like the KAT3.  The DB15 
cable from the K3 goes to the KAT500, and an identical cable goes from 
the KAT500 to KPA500.  When you power up the KAT500 for the first time, 
it will begin "remembering" the settings as it tunes when you QSY, and 
eventually, it will just recall them.  Most folks seem to run through 
all band/segment/antenna combinations once and get them all stored, 
that's what I did.  The segment size varies by band, most are 20KHz, 160 
is 10KHz I think, 10 is 100KHz and I think 6 is 200KHz.

If something happens to your antenna and the stored setting yields an 
SWR over a threshold [adjustable with the KAT500 utility], it will 
automatically retune.

If you do not have the DB15 cables connected, you have to feed initial 
RF to the KAT500 [and KPA500] so it can sense your QRG.
>
> In other words, the K3 combo with the amp and tuner will operate the
> same as the K3 and the 100 Watt internal tuner? Just QSY and talk???

Except for initial conditions [see above], yes, provided you have the 
DB15 cables connected.  If you don't have the DB15's, the KAT500 [and 
KPA500] will select the right band and values when you first transmit.

> I use wires for 160/75/40 (proper length elements for each band that the
> K3 handles easily). A small vertical for the rare interludes of using
> the higher bands (trapped - so no challenge for a tuner).

If the SWR presented to the KAT500 is below a threshold [adjustable in 
the Utility, I think, I haven't touched it], the KAT500 will go into 
byapass [i.e. not needed].  Via the KAT500 Utility, you can 
enable/disable each of the 3 antenna ports for each band.  If you 
disable Ant 2 for a particular band, when you are on that band, tapping 
the ANT switch will toggle between 1 and 3, skipping 2.  Hope this helps.

73,

Fred K6DGW
- Northern California Contest Club
- CU in the 2013 Cal QSO Party 5-6 Oct 2013
- www.cqp.org