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KAT3 and Six Meters ...

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Joe Subich, W4TV-4

KAT3 and Six Meters ...

I'm seeing a strange behavior with the KAT3 on six.

If I engage the tuner it finds a low SWR and stops tuning.
However, if I then close the Key the K3 shows "HI SWR" and
folds back. This happens even on the dummy load (1.15:1).
It does not happen on any other band.

Suggestions?

73,

... Joe, W4TV
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Svend Spanget

Re: KAT3 and Six Meters ...

RF feedback?
Svend, OZ7UV

Joe Subich, W4TV-4

Re: KAT3 and Six Meters ...

> RF feedback?

Not likely with a dummy load! However, I added choke cores to
the feedline with no change in behavior.

Note - I can easily achieve a 1:1 SWR (and no foldback) by using
CONFIG:LC SET.

73,

... Joe, W4TV

On 5/27/2011 3:28 PM, Svend Spanget wrote:

> RF feedback?
> Svend, OZ7UV
>
> --
> View this message in context: http://elecraft.365791.n2.nabble.com/KAT3-and-Six-Meters-tp6411527p6412296.html
> Sent from the Elecraft mailing list archive at Nabble.com.
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k1htv

Re: KAT3 and Six Meters ...

In reply to this post by Joe Subich, W4TV-4

Joe,
You are not alone. I've noticed the same problem here with my K3's ATU. With
the ATU in BYPASS the SWR is low on my 6M yagi. When I turn the ATU on and press
the tune button, the K3 finds a dip, but when I transmit, the SWR is much higher
than with the ATU turned on. Pressing the tune button a 2nd or 3rd time makes do
difference.

As you reported, this does not happen on any of the other HF bands.

73,
Rich - K1HTV

= = =

----Original Message-----
From: Joe Subich, W4TV [mailto:[hidden email]]
Sent: Friday, May 27, 2011 11:42 AM
To: Elecraft Reflector
Subject: [Elecraft] KAT3 and Six Meters ...

I'm seeing a strange behavior with the KAT3 on six.

If I engage the tuner it finds a low SWR and stops tuning.
However, if I then close the Key the K3 shows "HI SWR" and folds back. This
happens even on the dummy load (1.15:1).
It does not happen on any other band.

Suggestions?

73,

... Joe, W4TV

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K5DNL

Re: KAT3 and Six Meters ...

Hello all

I just tested and my swr is 1.0 to 1 with or with out
the tuner into M2 antenna.
However , I have my tune power ser at 10 watts,
but on 6 meters it's only 7.9 watts.
It's always been that way.

73 Ken K5DNL
--------------------------------------------------------

--- On Sat, 5/28/11, Rich - K1HTV <[hidden email]> wrote:

> From: Rich - K1HTV <[hidden email]>
> Subject: Re: [Elecraft] KAT3 and Six Meters ...
> To: "'Joe Subich, W4TV'" <[hidden email]>, "'Elecraft Reflector'" <[hidden email]>
> Date: Saturday, May 28, 2011, 6:16 AM
> Joe,
> You are not alone. I've noticed the same problem here
> with my K3's ATU. With
> the ATU in BYPASS the SWR is low on my 6M yagi. When I turn
> the ATU on and press
> the tune button, the K3 finds a dip, but when I transmit,
> the SWR is much higher
> than with the ATU turned on. Pressing the tune button a 2nd
> or 3rd time makes do
> difference.
>
> As you reported, this does not happen on any of the other
> HF bands.
>
> 73,
> Rich - K1HTV
>
> = = =
>
> ----Original Message-----
> From: Joe Subich, W4TV [mailto:[hidden email]]
>
> Sent: Friday, May 27, 2011 11:42 AM
> To: Elecraft Reflector
> Subject: [Elecraft] KAT3 and Six Meters ...
>
>
> I'm seeing a strange behavior with the KAT3 on six.
>
> If I engage the tuner it finds a low SWR and stops tuning.
> However, if I then close the Key the K3 shows "HI SWR" and
> folds back. This
> happens even on the dummy load (1.15:1).
> It does not happen on any other band.
>
> Suggestions?
>
> 73,
>
> ... Joe, W4TV
>
>
> ______________________________________________________________
> 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
>

Joe Subich, W4TV-4

Re: KAT3 and Six Meters ...

In reply to this post by k1htv

Rich,

Your symptoms are identical to mine.

I've done some additional diagnosis with some interesting but
confusing findings:

1) Switching to CONFIG:KAT3 = LC SET allows me to manually tune
the KAT3 for minimum SWR as indicated on the K3 SWR meter.

2) If I swap the tuner boards between my two K3s, the problem
stays in the K3 (does not follow the board).

3) The second K3/KAT3 works normally - pressing "ATU TUNE" on
Six will find the proper low SWR. The CA/Ct/L values found
automatically by the second K3 are the same as those I found
manually on the first unit.

73,

... Joe, W4TV

On 5/28/2011 7:16 AM, Rich - K1HTV wrote:

> Joe,
> You are not alone. I've noticed the same problem here with my K3's ATU. With
> the ATU in BYPASS the SWR is low on my 6M yagi. When I turn the ATU on and press
> the tune button, the K3 finds a dip, but when I transmit, the SWR is much higher
> than with the ATU turned on. Pressing the tune button a 2nd or 3rd time makes do
> difference.
>
> As you reported, this does not happen on any of the other HF bands.
>
> 73,
> Rich - K1HTV
>
> = = =
>
> ----Original Message-----
> From: Joe Subich, W4TV [mailto:[hidden email]]
> Sent: Friday, May 27, 2011 11:42 AM
> To: Elecraft Reflector
> Subject: [Elecraft] KAT3 and Six Meters ...
>
>
> I'm seeing a strange behavior with the KAT3 on six.
>
> If I engage the tuner it finds a low SWR and stops tuning.
> However, if I then close the Key the K3 shows "HI SWR" and folds back. This
> happens even on the dummy load (1.15:1).
> It does not happen on any other band.
>
> Suggestions?
>
> 73,
>
> ... Joe, W4TV
>
>
>

Jim Sheldon

Re: KAT3 and Six Meters ...

In reply to this post by k1htv

Rich and Joe,
I HAVE noticed the same problem on other bands as well. Specifically, 160 meters, 15 meters and 10 meters as well as now on 6. I don't notice it all the time on 6 and I thought it stoped when I put the ferrites on the antenna cables, but it cropped up again this morning on 6. Later it reared it's head on 15.

I have not noticed it on any of the other bands, but it may be related to a particular segment of the band
and I may not have actually transmitted or run the tuner on that segment yet.

My antennas are resonant on the bands they are used for with the exception of the inverted L which is resonant about 1850 on 160 and used with the tuner for the lower end of 160 and on 80.

The problem does not seem to occur on 80 and on any other band but 160 with the L. The ATU will find a 1:1 match on all bands using the L and doesn't exhibit the tuning anomaly on anything but 160 with that antenna.

That said, a second (sometimes it takes 3) touch of the ATU Tune button usually causes it to tune for a much longer period of time but it tends to find a match closer to 1:0. This is particularly annoying in a contest on 160. On 6, the 3 element yagi is resonant at 50.100 and I normally don't use the tuner, but I started experimenting with it after this problem was reported and I discovered that my K3 exhibits the same anomaly that Rich and Joe reported.

Jim Sheldon - W0EB

> Joe,
> You are not alone. I've noticed the same problem here with my K3's
> ATU. With
> the ATU in BYPASS the SWR is low on my 6M yagi. When I turn the ATU
> on and press
> the tune button, the K3 finds a dip, but when I transmit, the SWR
> is much higher
> than with the ATU turned on. Pressing the tune button a 2nd or 3rd
> time makes do
> difference.
>
> As you reported, this does not happen on any of the other HF bands.
>
> 73,
> Rich - K1HTV
>
> = = =
>
> ----Original Message-----
> From: Joe Subich, W4TV [mailto:[hidden email]]
> Sent: Friday, May 27, 2011 11:42 AM
> To: Elecraft Reflector
> Subject: [Elecraft] KAT3 and Six Meters ...
>
>
> I'm seeing a strange behavior with the KAT3 on six.
>
> If I engage the tuner it finds a low SWR and stops tuning.
> However, if I then close the Key the K3 shows "HI SWR" and folds
> back. This
> happens even on the dummy load (1.15:1).
> It does not happen on any other band.
>
> Suggestions?
>
> 73,
>
> ... Joe, W4TV

Re: KAT3 and Six Meters ...

I don't know it is your problem or not, but I found that I have a 2/1 SWR on 6
meters with no tuner when my amp relay is in line, but near 1/1 if I connect the
coax around the amp. For diagnosis purposes if you are having unexplained
results it is a good idea to temporarily remove as many relays, switches,
connectors and the like from the antenna feed and see if the trouble persists.
Try connecting to a dummy load or maybe a non 50 ohm dummy load if you have one
and see if you still have the problem. Anything in the circuit can cause
trouble, not just antennas and tuners.
Willis 'Cookie' Cooke
K5EWJ & Trustee N5BPS, USS Cavalla, USS Stewart

________________________________
From: Jim Sheldon <[hidden email]>
To: Rich - K1HTV <[hidden email]>; Elecraft Reflector
<[hidden email]>
Sent: Sun, May 29, 2011 10:03:31 AM
Subject: Re: [Elecraft] KAT3 and Six Meters ...

Rich and Joe,
I HAVE noticed the same problem on other bands as well. Specifically, 160
meters, 15 meters and 10 meters as well as now on 6. I don't notice it all the
time on 6 and I thought it stoped when I put the ferrites on the antenna cables,
but it cropped up again this morning on 6. Later it reared it's head on 15.

I have not noticed it on any of the other bands, but it may be related to a
particular segment of the band

and I may not have actually transmitted or run the tuner on that segment yet.

My antennas are resonant on the bands they are used for with the exception of
the inverted L which is resonant about 1850 on 160 and used with the tuner for
the lower end of 160 and on 80.

The problem does not seem to occur on 80 and on any other band but 160 with the
L. The ATU will find a 1:1 match on all bands using the L and doesn't exhibit
the tuning anomaly on anything but 160 with that antenna.

That said, a second (sometimes it takes 3) touch of the ATU Tune button usually
causes it to tune for a much longer period of time but it tends to find a match
closer to 1:0. This is particularly annoying in a contest on 160. On 6, the 3
element yagi is resonant at 50.100 and I normally don't use the tuner, but I
started experimenting with it after this problem was reported and I discovered
that my K3 exhibits the same anomaly that Rich and Joe reported.

Jim Sheldon - W0EB

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Jim Sheldon

Re: KAT3 and Six Meters ...

In reply to this post by Joe Subich, W4TV-4

I did forget to mention that I have done the dummy load test and the problem persists, at least on 6 and 160 meters on the dummy. I haven't had time to rigorously test the other bands, but I do suspect there's an anomaly in the tuning algorithm that allows this to crop up. I had mentioned the 160 meter problem a while back in a post to the reflector, but never got a response. It was just before Dayton and I expect it probably got lost in the shuffle as they were getting ready for the show.

Jim - W0EB

> Hi Jim,
> Thanks for your input on the subject. Maybe the technical folks at
> Elecraft
> can determine a fix for this problem. Hope that the 'Magic Band' is
> as good as
> last year.
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wayne burdick

Re: KAT3 and Six Meters ...

Administrator

I just tested this on my K3.

When I have the ATU in on 6 meters, tapping ATU TUNE tunes the
antenna, and 1.0-1 is displayed at the end.

I can also set LC SET mode, exit the menu, and tap ATU TUNE, which
shows L and C. I can then adjust L and C using VFO A and B. After an
adjustment, TUNE shows the effect of L/C changes on SWR as expected.

Don't forget that ATU in/out is stored per-antenna, so you can have it
engaged for one antenna but bypassed for the other. There may have
been a bug in this prior to revision 4.33 -- I have to check my notes
on that.

Are you doing it differently from the above?

73,
Wayne
N6KR

On May 29, 2011, at 4:57 PM, Jim Sheldon wrote:

> I did forget to mention that I have done the dummy load test and the
> problem persists, at least on 6 and 160 meters on the dummy. I
> haven't had time to rigorously test the other bands, but I do
> suspect there's an anomaly in the tuning algorithm that allows this
> to crop up. I had mentioned the 160 meter problem a while back in a
> post to the reflector, but never got a response. It was just before
> Dayton and I expect it probably got lost in the shuffle as they were
> getting ready for the show.
>
> Jim - W0EB
>
>> Hi Jim,
>> Thanks for your input on the subject. Maybe the technical folks at
>> Elecraft
>> can determine a fix for this problem. Hope that the 'Magic Band' is
>> as good as
>> last year.
> ______________________________________________________________
> 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