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KAT500 tuning problem

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Bill-3

KAT500 tuning problem

For the past month I have been experiencing tuning problems with the
KAT500.

The antenna in question is a simple 75 meter dipole fed with coax. You
tune the antenna at 3922, 2955 and 3975 - just for example. When you
return to those frequencies, a few hours later, the tuning is all off
and the KPA500 demos its displeasure by beeping and flashing lights.
Retuning will again hold for a few hours, then all goes haywire again.

I have given shake test to the antenna/halyards - with an analog SWR
bridge in line - and see nothing to indicate breaks or damage. I
replaced the feed line and it still does everything the same. All coax
lines inside have also been changed out - to no avail.

I should mention that this problem exists on an alternate antenna also.
The alternate is also a dipole type. No remote baluns, nothing other
than simple center insulators. Chances are they are built properly -
been doing it for over 55 years and have never experienced anything like
this.

I have reset the KAT500 to default a couple of times - reinstalled the
software - all the things you do with black boxes - went through the
training thing. I spoken with Elecraft and followed their instructions
to the letter also (which were the same as what I had been doing). It
all holds well for a few hours, then goes wacko.

If I have to push the buttons every time I QSY, there is little reason
to continuing using the KAT500. Of course that makes using the KPA500
more difficult or impossible.

Shipping is expensive and so are service charges - the tuner is way out
of warranty.

Anyone have experiences such as these or suggestions?

I am seriously considering regressing to a manual tuner.

Thanks,

Bill W2BLC K-Line

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jh3sif

Re: KAT500 tuning problem

Have you checked your KAT500 with a dummy load instead of feed line?
This would tell you either your KAT500 or feed line to antenna (and antenna) is in trouble.

73 de JH3SIF, Keith

> 2016/02/05 6:17、Bill <[hidden email]> のメール：
>
> For the past month I have been experiencing tuning problems with the KAT500.
>
> The antenna in question is a simple 75 meter dipole fed with coax. You tune the antenna at 3922, 2955 and 3975 - just for example. When you return to those frequencies, a few hours later, the tuning is all off and the KPA500 demos its displeasure by beeping and flashing lights. Retuning will again hold for a few hours, then all goes haywire again.
>
> I have given shake test to the antenna/halyards - with an analog SWR bridge in line - and see nothing to indicate breaks or damage. I replaced the feed line and it still does everything the same. All coax lines inside have also been changed out - to no avail.
>
> I should mention that this problem exists on an alternate antenna also. The alternate is also a dipole type. No remote baluns, nothing other than simple center insulators. Chances are they are built properly - been doing it for over 55 years and have never experienced anything like this.
>
> I have reset the KAT500 to default a couple of times - reinstalled the software - all the things you do with black boxes - went through the training thing. I spoken with Elecraft and followed their instructions to the letter also (which were the same as what I had been doing). It all holds well for a few hours, then goes wacko.
>
> If I have to push the buttons every time I QSY, there is little reason to continuing using the KAT500. Of course that makes using the KPA500 more difficult or impossible.
>
> Shipping is expensive and so are service charges - the tuner is way out of warranty.
>
> Anyone have experiences such as these or suggestions?
>
> I am seriously considering regressing to a manual tuner.
>
> Thanks,
>
> Bill W2BLC K-Line
>
>
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
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> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]

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Don Wilhelm-4

Re: KAT500 tuning problem

In reply to this post by Bill-3

Bill,

After you do the initial TUNE (training the ATU), do you switch it to
MAN? If not try that and see if it corrects your situation.
If not, then it is time to contact support.

73,
Don W3FPR

On 2/4/2016 4:17 PM, Bill wrote:

> For the past month I have been experiencing tuning problems with the
> KAT500.
>
> The antenna in question is a simple 75 meter dipole fed with coax. You
> tune the antenna at 3922, 2955 and 3975 - just for example. When you
> return to those frequencies, a few hours later, the tuning is all off
> and the KPA500 demos its displeasure by beeping and flashing lights.
> Retuning will again hold for a few hours, then all goes haywire again.
>
> I have given shake test to the antenna/halyards - with an analog SWR
> bridge in line - and see nothing to indicate breaks or damage. I
> replaced the feed line and it still does everything the same. All coax
> lines inside have also been changed out - to no avail.
>
> I should mention that this problem exists on an alternate antenna
> also. The alternate is also a dipole type. No remote baluns, nothing
> other than simple center insulators. Chances are they are built
> properly - been doing it for over 55 years and have never experienced
> anything like this.
>
> I have reset the KAT500 to default a couple of times - reinstalled the
> software - all the things you do with black boxes - went through the
> training thing. I spoken with Elecraft and followed their instructions
> to the letter also (which were the same as what I had been doing). It
> all holds well for a few hours, then goes wacko.
>

Wes (N7WS)

Re: KAT500 tuning problem

In reply to this post by Bill-3

After a good tune, I would use the KAT500 utility to examine and record the
selected component values.

When the failure occurs, before retuning I would look at them again and see if
they are the same.

Also after a good tune, I would run up and down the band to cycle the relays and
see if things are the same when returning to a previously tuned band segment.

On 2/4/2016 2:17 PM, Bill wrote:

> For the past month I have been experiencing tuning problems with the KAT500.
>
> The antenna in question is a simple 75 meter dipole fed with coax. You tune
> the antenna at 3922, 2955 and 3975 - just for example. When you return to
> those frequencies, a few hours later, the tuning is all off and the KPA500
> demos its displeasure by beeping and flashing lights. Retuning will again hold
> for a few hours, then all goes haywire again.
>
> I have given shake test to the antenna/halyards - with an analog SWR bridge
> in line - and see nothing to indicate breaks or damage. I replaced the feed
> line and it still does everything the same. All coax lines inside have also
> been changed out - to no avail.
>
> I should mention that this problem exists on an alternate antenna also. The
> alternate is also a dipole type. No remote baluns, nothing other than simple
> center insulators. Chances are they are built properly - been doing it for
> over 55 years and have never experienced anything like this.
>
> I have reset the KAT500 to default a couple of times - reinstalled the
> software - all the things you do with black boxes - went through the training
> thing. I spoken with Elecraft and followed their instructions to the letter
> also (which were the same as what I had been doing). It all holds well for a
> few hours, then goes wacko.
>
> If I have to push the buttons every time I QSY, there is little reason to
> continuing using the KAT500. Of course that makes using the KPA500 more
> difficult or impossible.
>
> Shipping is expensive and so are service charges - the tuner is way out of
> warranty.
>
> Anyone have experiences such as these or suggestions?
>
> I am seriously considering regressing to a manual tuner.
>
> Thanks,
>
> Bill W2BLC K-Line
>
>
>
> ______________________________________________________________
> 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]
>

Jim AB3CV

Re: KAT500 tuning problem

Since you are running KPA500 along with the KAT500 and you stated you don't
have a balun, I assume you don't have a common mode choke either.

I suggest a trip to http://audiosystemsgroup.com/RFI-Ham.pdf as I suspect
you have RF in the shack.

73

jim ab3cv

On Thu, Feb 4, 2016 at 7:11 PM, Wes (N7WS) <[hidden email]> wrote:

> After a good tune, I would use the KAT500 utility to examine and record
> the selected component values.
>
> When the failure occurs, before retuning I would look at them again and
> see if they are the same.
>
> Also after a good tune, I would run up and down the band to cycle the
> relays and see if things are the same when returning to a previously tuned
> band segment.
>
> On 2/4/2016 2:17 PM, Bill wrote:
>
>> For the past month I have been experiencing tuning problems with the
>> KAT500.
>>
>> The antenna in question is a simple 75 meter dipole fed with coax. You
>> tune the antenna at 3922, 2955 and 3975 - just for example. When you return
>> to those frequencies, a few hours later, the tuning is all off and the
>> KPA500 demos its displeasure by beeping and flashing lights. Retuning will
>> again hold for a few hours, then all goes haywire again.
>>
>> I have given shake test to the antenna/halyards - with an analog SWR
>> bridge in line - and see nothing to indicate breaks or damage. I replaced
>> the feed line and it still does everything the same. All coax lines inside
>> have also been changed out - to no avail.
>>
>> I should mention that this problem exists on an alternate antenna also.
>> The alternate is also a dipole type. No remote baluns, nothing other than
>> simple center insulators. Chances are they are built properly - been doing
>> it for over 55 years and have never experienced anything like this.
>>
>> I have reset the KAT500 to default a couple of times - reinstalled the
>> software - all the things you do with black boxes - went through the
>> training thing. I spoken with Elecraft and followed their instructions to
>> the letter also (which were the same as what I had been doing). It all
>> holds well for a few hours, then goes wacko.
>>
>> If I have to push the buttons every time I QSY, there is little reason to
>> continuing using the KAT500. Of course that makes using the KPA500 more
>> difficult or impossible.
>>
>> Shipping is expensive and so are service charges - the tuner is way out
>> of warranty.
>>
>> Anyone have experiences such as these or suggestions?
>>
>> I am seriously considering regressing to a manual tuner.
>>
>> Thanks,
>>
>> Bill W2BLC K-Line
>>
>>
>>
>> ______________________________________________________________
>> 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]
>>
>>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
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> 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]
>

Bill-3

Re: KAT500 tuning problem

I have done the reading of the printout - some really crazy SWR numbers
for the antenna that I know are not correct.

So far as RF in the shack - I might consider that - if things had not
been working correctly until abut a month ago. Nothing has changed until
then, causing all the efforts and modifications to isolate the problem.
Other rigs - with ATUs - are working just fine with the entire station.

Everything RF is brought into the house to a well grounded bulkhead.
Longest run from any rig/amp/tuner is 6 feet to the bulkhead.
Interconnects are all as short as possible. Equipment is all connected
to a central grounding point. In other words - been there and done that
out of habit.

Tonight I am running barefoot with the antenna running direct to the K3
- all is good. Tomorrow I will try to get everything back to where it
was before this mess started and tune when I QSO as a routine and forget
whatever else the tuner is supposed to do. Sure reminds me of what it
was doing when I first got it.

A manual tuner will be ordered very soon and the KAT500 removed from the
lineup.

I don't see a magic bullet on this - thanks for all the ideas.

Bill W2BLC

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john@kk9a.com

Re: KAT500 tuning problem

In reply to this post by Bill-3

It is possible that you have bad coax, a bad connection or water ingress in
your antenna system. It would be interesting to see if a manual tuner
remains stable.

John KK9A

Bill w2blc at nycap.rr.com
Thu Feb 4 19:39:04 EST 2016
for the antenna that I know are not correct.

So far as RF in the shack - I might consider that - if things had not
been working correctly until abut a month ago. Nothing has changed until
then, causing all the efforts and modifications to isolate the problem.
Other rigs - with ATUs - are working just fine with the entire station.

Everything RF is brought into the house to a well grounded bulkhead.
Longest run from any rig/amp/tuner is 6 feet to the bulkhead.
Interconnects are all as short as possible. Equipment is all connected
to a central grounding point. In other words - been there and done that
out of habit.

Tonight I am running barefoot with the antenna running direct to the K3
- all is good. Tomorrow I will try to get everything back to where it
was before this mess started and tune when I QSO as a routine and forget
whatever else the tuner is supposed to do. Sure reminds me of what it
was doing when I first got it.

A manual tuner will be ordered very soon and the KAT500 removed from the
lineup.

I don't see a magic bullet on this - thanks for all the ideas.

Bill W2BLC

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Bill-3

Re: KAT500 tuning problem

That was my first thought - so I laid out a new coax to the antenna.

That said, this morning everything works just fine. I can only figure
the KAT500 heard me say that it was leaving and it decided to work. Be
interesting to see how long this holds.

Bill W2BLC
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