[Elecraft] KPA-1500 Antenna Tuner "Hunting"

[Eric Norris]

I had a similar issue, and received this reply from Dick Dievendorff.   I
hope it helps you, as it did me.  Forwarded with Dick's permission.

73 Eric WD6DBM

On Wed, Nov 13, 2019 at 6:14 AM, Dick Dievendorff
 wrote:
Hi, Eric!

There is an ATU MODE SWITCH menu setting that might influence this.  With
"ALL BANDS", the ATU Mode doesn't change from band to band. If you change
the ATU Mode to BYP on one band, it should stay bypassed as you switch from
band to band.

If you have ATU MODE SWITCH set to "PER BAND" and turn the ATU to Bypass on
20 meters, then band switch to 30 meters, the ATU should return to the
last-used ATU MODE on the new (30-meter) band. That might enable the ATU on
band switch.

I did exactly what you said you did with 2.38; I set the amp to STBY, ATU
mode to BYP, turned the K3 ATU on and pressed ATU TUNE on the K3.  The
amp's SWR bar shows SWR, but the amp's ATU didn't change from its bypassed
setting and it didn't start tuning.

If the KPA1500 ATU Mode is "Bypass",  (ATU IN LED dark) it shouldn't start
tuning on its own.  If both ATU IN and BYP are lit, that means the ATU Mode
is "IN" (meaning "ATU function enabled"), but the current ATU setting is
bypassed.  Then it should change ATU settings when needed.

It's a fine point on ATU MODE bypass versus ATU MODE IN with ATU setting
currently bypassed. The ATU, when in, can set relays for a number of
inductors and capacitors. During ATU tuning it might find that "all relays
bypassed" is the best setting to choose. The ATU then uses its "bypassed"
relay settings, but the ATU MODE is still "in", meaning "ATU function
enabled".

I didn't initially show both LEDs when the ATU is both "enabled" and the
current ATU setting is "bypassed", but in Field Test it was suggested that
we indicate when the ATU is currently set to its bypassed setting. I didn't
do that in KAT500.  So if the "IN" LED is lit, the ATU is not in ATU MODE
BYP, even if the ATU BYP LED is also lit.

If the amp is in Mode STBY, and the ATU is *not* bypassed, the ATU should
retune if its "ATU HiSWR" setting is on for 30 meters. The intent is that
the KPA1500's ATU should be available at 100W, with the KPA1500 in STBY,
perhaps some don't have an ATU in their exciter and can use the amp's ATU
without using the amp's PA.

If you want the amp's ATU available on 30 meters, but don't want it
retuning on its own, turn off ATU HiSWR RETUNE for 30 meters.

Hope I haven't made this more confusing...  We're trying to satisfy a lot
of differing situations.

73 de Dick, K6KR

On Sun, Aug 2, 2020, 6:38 AM N4ZR  wrote:

> Last night in NAQP I noticed that on 80 meters my tuner would hunt
> endlessly, calling for tune power, then finishing, then asking again
> with the ATU IN LED blinking.  
>
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Re: [Elecraft] KPA-1500 Antenna Tuner "Hunting"

[David Bunte]

Pete -

I don't have a KPA1500, but do have a KPA500 with a KAT500... and the first
thing that comes to mind is manual vs auto on the tuner... IF they can be
selected on the '1500. With the KAT500 after the tuner has found a matching
solution for each band segment, I then put the tuner in manual,  and when I
change bands the tuner selects the correct tuning solution and it does not
seek a new one while I am transmitting. I know that was the advice for the
KAT500 from the time I first got mine years ago. I assume that is valid
advice for the tuner in the KPA1500, assuming that is an option.

Very 73 de Dave - K9FN

On Sun, Aug 2, 2020 at 9:39 AM N4ZR  wrote:

> Last night in NAQP I noticed that on 80 meters my tuner would hunt
> endlessly, calling for tune power, then finishing, then asking again
> with the ATU IN LED blinking.  I retrained the memory on each relevant
> band segment, and that stopped the hunting, but I noticed that instead
> of QSYing smoothly from one segment to another when I would pounce on a
> CQer, it would go through a tune cycle before settling down in normal
> operation.  I don't think this is normal, but don't know what to do.
> Should I erase my 80M segment memories and reload them?
>
> Oh BTW, I was not running the amp last night - just using the tuner.
> I'm a good boy.
>
> --
> 73, Pete N4ZR
> Check out the Reverse Beacon Network
> at , now
> spotting RTTY activity worldwide.
> For spots, please use your favorite
> "retail" DX cluster.
>
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[Elecraft] KPA-1500 Antenna Tuner "Hunting"

[N4ZR]

Last night in NAQP I noticed that on 80 meters my tuner would hunt 
endlessly, calling for tune power, then finishing, then asking again 
with the ATU IN LED blinking.  I retrained the memory on each relevant 
band segment, and that stopped the hunting, but I noticed that instead 
of QSYing smoothly from one segment to another when I would pounce on a 
CQer, it would go through a tune cycle before settling down in normal 
operation.  I don't think this is normal, but don't know what to do.  
Should I erase my 80M segment memories and reload them?


Oh BTW, I was not running the amp last night - just using the tuner.  
I'm a good boy.


--
73, Pete N4ZR
Check out the Reverse Beacon Network
at , now
spotting RTTY activity worldwide.
For spots, please use your favorite
"retail" DX cluster.

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