[Elecraft] KPA-1500 tuner question

[K9MA]

If HiSWR AUTOTUNE is enabled, this would be the expected behavior. 
However, ATU switching at the start of transmission sometimes happens 
even with it disabled.

Elecraft is working on the ATU firmware in relation to this issue. I 
noticed it some time ago. Even with the HiSWR AUTOTUNE turned off and 
AUXBUS frequency data from the K3, the ATU sometimes switches when 
transmission starts. I don't know quite what it sounds like on the other 
end, but I seem to get asked for repeats off when it happens. Although 
the K3 sends frequency data to the KPA1500 only once per second, that 
isn't the main problem, as the switching occurs even if tuning has 
stopped for longer than that.

Stay tuned.

73,
Scott K9MA

On 2/21/2019 09:36, Jim Miller wrote:
> Things to check
>
> Could be bad aux cable. Is it from Elecraft?
>
> Do you have anything else connected to aux?
>
> Are you sure connectors are fully engaged?
>
> On Feb 21, 2019, at 10:21 AM, Walter J. Legowski <sue.walt at dososaur.com> wrote:
>
> I experienced the same thing, especially on 20M.  The tuner is apparently ignoring some of the signals on the AUXBUS line.  I put a scope on that line.  I can see, some of the time, the amplifier responding to the signal with a "clunk" as the tuner relays adjust to the new segment.  The rest of the time, I see the signal, but no response from the amp.  If you attempt to transmit when the signal is ignored, you get chattering relays followed by "ATU Retune Complete" on the amp display.  I took a photo of the signal trace and sent it to Support yesterday.  They haven't gotten back to me yet.
>
> Walt, WA1KKM
>
>
>> On 2/21/19 3:36 AM, Peter Dougherty wrote:
>> Hi all,
>> Something I noticed this past weekend in the contest about the KPA1500,
>> especially on 80 and 160, where the internal tuner was needed on antennas
>> that were above ~1.5:1 SWR. When I changed frequencies into a range that
>> required retuning, I had to manually press the ATU control and initiate a
>> tune sequence, or else when I was auto-sending CW my call would get cut off
>> as the tuner set its needed values.
>> Since I'd memorized the entire band(s) ahead of time, is there a way for the
>> memorized tuning solutions to load on QSY, rather than on RF application? It
>> really slowed me down as I was S&Ping my way through the low bands on Friday
>> night.
>>   ---------------------------------------------
>> 73 and Good DX
>> Peter, W2IRT
>> President, North Jersey DX Association
>> DXCC Card Checker
>> Letter O Manager, ARRL Incoming 2nd District QSL bureau
>>

-- 
Scott  K9MA

k9ma at sdellington.us