[Elecraft] Re: K3 Antenna 1/2 Operation

[wayne burdick]

Windy Dankoff KM5Q wrote:

> I set the ATU for for either antenna, or one then the other, but it 
> NEVER
> auto-adjusts when I switch antennas. Never on any band or with any
> (mis)tuning of my vertical, have I heard more than one relay click  
> when
> switching ANT 1/2 (no ATU reset).

Windy,

The relays on the KAT3 are very quiet. Multiple relays are definitely 
being switched when you go from one antenna to the other -- but they're 
all switched simultaneously, so it sounds like one relay.

Here's a way to prove it. Auto-tune both antennas at a given frequency 
(presumably both get close to 1:1). Then do a TUNE to check the SWR one 
ANT 1. Now switch to ANT 2 and do a TUNE to check its SWR. It should 
still be 1:1, because the relays *did* switch.

Another way to prove that the relays switched is to use the KAT3's "LC 
SET" mode (in the menu). This is normally used to manually adjust LC 
values for troubleshooting purposes, but you can also use it to check 
the ATU's present LC settings:

   1. Set the KAT3 for AUTO mode and tune up both antennas.
   2. Set CONFIG:KAT3 to LC SET and exit the menu.
   3. Tap ATU TUNE: It'll show you the L and C values as well as
      where the 'C' is (CT = xmit side of the L-network, CA = ant side).
   4. Tap ATU TUNE to clear the LC display.
   5. Set CONFIG:KAT3 to AUTO and exit the menu.
   6. Tap ANT to switch to the other antenna, then repeat steps 2-5;
      you'll see a different LC value in effect.

We're also going to add multiple ATU LC storage segments per band.

73,
Wayne
N6KR

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