KPA-1500 ATU operation

[charles-2]

I should have checked for a new manual since the manual that came with
my KPA-1500 has 20 Kc bins which I see are now 10 Kc bins.  In addition,
the tuning frequencies have been changed to 10 Kc increments.  I think
that is why I was getting unexplained results from the tuner as I tuned
across the band.  I will "re-teach" the KPA-1500 using these new
parameters.

Just to make sure, however, does everyone agree the current concept is
the first bin on 80m would be 10 Kc wide (3.500 to 3.510) and the
correct tune-up frequency to "teach" the KPA-1500 for that bin would be
3.505 Kc ?

Secondly, the KPA-1500 would proceed to the next "taught" tuning
parameters (at 3.515) when the xcvr frequency would cross into the next
bin slightly higher than 3.510 ?

Would appreciate all interest parties to agree or disagree with this
scenario.

Thanks for all the comments, I'm glad Electraft made the bin size
smaller because feedpoint impedances can change rapidly on 80M.

Thanks, K5UA
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[Bob McGraw - K4TAX]

Yes I got caught with using reference to an older manual on this topic.   my oops

Bob, K4TAX


Sent from my iPhone

> On Dec 11, 2019, at 11:50 AM, [hidden email] wrote:
>
> I should have checked for a new manual since the manual that came with my KPA-1500 has 20 Kc bins which I see are now 10 Kc bins.  In addition, the tuning frequencies have been changed to 10 Kc increments.  I think that is why I was getting unexplained results from the tuner as I tuned across the band.  I will "re-teach" the KPA-1500 using these new parameters.
>
> Just to make sure, however, does everyone agree the current concept is the first bin on 80m would be 10 Kc wide (3.500 to 3.510) and the correct tune-up frequency to "teach" the KPA-1500 for that bin would be 3.505 Kc ?
>
> Secondly, the KPA-1500 would proceed to the next "taught" tuning parameters (at 3.515) when the xcvr frequency would cross into the next bin slightly higher than 3.510 ?
>
> Would appreciate all interest parties to agree or disagree with this scenario.
>
> Thanks for all the comments, I'm glad Electraft made the bin size smaller because feedpoint impedances can change rapidly on 80M.
>
> Thanks, K5UA
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]

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[K9MA]

One thing that may confuse things is that the frequency counter has only
8 kHz (?) resolution, and it takes priority over data from the radio.
I'm unsure about this, as my KPA1500 doesn't often seem to change ATU
setting when start transmitting. It is possible, though, that the low
resolution counter thinks the frequency is in an adjacent bin.

If it were up to me, I would not allow the counter to have priority
unless the frequency difference is at least several bin's worth. That
way, transmission wouldn't be needlessly interrupted because of the low
counter resolution, but the amp would still be protected against
erroneous data from the radio. But Dick probably has more important
things to worry about.

73,
Scott K9MA


On 12/11/2019 11:34, [hidden email] wrote:

> I should have checked for a new manual since the manual that came with
> my KPA-1500 has 20 Kc bins which I see are now 10 Kc bins.  In
> addition, the tuning frequencies have been changed to 10 Kc
> increments.  I think that is why I was getting unexplained results
> from the tuner as I tuned across the band.  I will "re-teach" the
> KPA-1500 using these new parameters.
>
> Just to make sure, however, does everyone agree the current concept is
> the first bin on 80m would be 10 Kc wide (3.500 to 3.510) and the
> correct tune-up frequency to "teach" the KPA-1500 for that bin would
> be 3.505 Kc ?
>
> Secondly, the KPA-1500 would proceed to the next "taught" tuning
> parameters (at 3.515) when the xcvr frequency would cross into the
> next bin slightly higher than 3.510 ?
>
> Would appreciate all interest parties to agree or disagree with this
> scenario.
>
> Thanks for all the comments, I'm glad Electraft made the bin size
> smaller because feedpoint impedances can change rapidly on 80M.
>
> Thanks, K5UA
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]

--
Scott  K9MA

[hidden email]

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