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KAT-500 auto-tuning issue with SSB vs. CW

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KAT-500 auto-tuning issue with SSB vs. CW

I am primarily a CW operator, but participated in the SSB Sweepstakes over this past weekend, running low power (100W) from my K3S, which runs through my KPA-500 and KAT-500 to a SteppIR 3-element beam with the 30/40 meter loop), a 40 meter wire dipole, and an 80 meter wire inverted V. During the contest, I repeatedly noticed that the KAT-500 was not re-tuning automatically to adjust to frequency changes based only on my SSB transmissions. But I found that if if I switched to CW for a couple of brief transmissions, the KAT-500 quickly re-tuned and reduced my SWR to near 1:1, so I could then switch back to SSB and complete the contact.

[I retune the SteppIR manually as I change frequency, but the beam is only 40 feet up, and interacts with lots of trees, power lines, and other problematic structures close to my tiny 100 by 100 foot property, so the antenna itself is not always perfectly matched.]

Has anybody experienced this problem or solved it?

73 -
Rich, K1DJ

Sent from my iPad
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ANDY DURBIN

KAT-500 auto-tuning issue with SSB vs. CW

"Has anybody experienced this problem or solved it?"

I don't expect my KAT500 to re-tune with an SSB transmission since I send it the exact TX frequency before I start to transmit. However, it is my understanding that commands FCCS; and FCMD; were added to KAT500 firmware to deal with exactly the situation you describe.

I'd suggest a review of the KAT500 Serial Command Reference. Values can be adjusted with the KAT500 utility.

Andy, k3wyc
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Bob McGraw - K4TAX

Re: KAT-500 auto-tuning issue with SSB vs. CW

There are SWR parameters that can be changed in the KAT500 Utility. I
suggest you install this on your computer, connect the KAT500 and
initiate the application.

I have trained my KAT500 to use certain antennas on certain bands and
for the lower frequencies, I have forced a tune ever 25 kHz. Then as I
tune the VFO the values in the tuner change based on previous
determinations. This includes changing antennas based on band. As to
the difference in SSB and CW, I don't find any. Also, after doing the
training, I normally operate the KAT500 in the MANual mode.

Also in the K3S manual, see KAT3 topic, page 60, for information on
establishing VFO tracking with the KAT500. When VFO tracking is
enabled, the KAT500's L network will be continuously updated as the VFO
is tuned.

73

Bob, K4TAX

On 11/19/2018 11:07 AM, ANDY DURBIN wrote:

> "Has anybody experienced this problem or solved it?"
>
>
> I don't expect my KAT500 to re-tune with an SSB transmission since I send it the exact TX frequency before I start to transmit. However, it is my understanding that commands FCCS; and FCMD; were added to KAT500 firmware to deal with exactly the situation you describe.
>
>
> I'd suggest a review of the KAT500 Serial Command Reference. Values can be adjusted with the KAT500 utility.
>
>
> Andy, k3wyc
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Don Wilhelm

Re: KAT-500 auto-tuning issue with SSB vs. CW

In reply to this post by Elecraft mailing list

Rich,

Are you operating with the KAT500 in AUTO mode?
You should train the antenna (using TUNE) on all bands and all antennas
at 25kHz intervals for each band.
Then change the KAT500 to MAN.

The KAT500 will follow your frequency and change to the pre-set L/C
values for that band and antenna automatically.
If you have the latest firmware, it will even follow the K3/K3S in receive.

73,
Don W3FPR

On 11/19/2018 5:28 AM, K1dj via Elecraft wrote:

> I am primarily a CW operator, but participated in the SSB Sweepstakes over this past weekend, running low power (100W) from my K3S, which runs through my KPA-500 and KAT-500 to a SteppIR 3-element beam with the 30/40 meter loop), a 40 meter wire dipole, and an 80 meter wire inverted V. During the contest, I repeatedly noticed that the KAT-500 was not re-tuning automatically to adjust to frequency changes based only on my SSB transmissions. But I found that if if I switched to CW for a couple of brief transmissions, the KAT-500 quickly re-tuned and reduced my SWR to near 1:1, so I could then switch back to SSB and complete the contact.
>
> [I retune the SteppIR manually as I change frequency, but the beam is only 40 feet up, and interacts with lots of trees, power lines, and other problematic structures close to my tiny 100 by 100 foot property, so the antenna itself is not always perfectly matched.]
>
> Has anybody experienced this problem or solved it?
>
> 73 -
> Rich, K1DJ
>
> Sent from my iPad
> ______________________________________________________________
> Elecraft mailing list
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ANDY DURBIN

Re: KAT-500 auto-tuning issue with SSB vs. CW

In reply to this post by ANDY DURBIN

"The KAT500 will follow your frequency and change to the pre-set L/C values for that band and antenna automatically."

Yes that's all wonderful if a K3, or some other means, provides the TX frequency to the KAT500. The OP does not say he is using a K3 and does not say that any other frequency interface is being used.

it was my assumption, based on the information in the first post, that RF sensing is being used and it is not working for the SSB phone signal.

Andy, k3wyc

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Don Wilhelm

Re: KAT-500 auto-tuning issue with SSB vs. CW

The KAT500, will do the same for any transceiver - except for following
the receive frequency.
After training the tuner, when the KAT500 receives a burst of RF, it
will tune to the remembered L/C combination for the frequency received,
it will go immediately to that combination.
Train in AUTO mode, then switch to MAN for reliable operation.

73,
Don
W3FPR

On 11/19/2018 6:39 PM, ANDY DURBIN wrote:

> "The KAT500 will follow your frequency and change to the pre-set L/C values for that band and antenna automatically."
>
>
> Yes that's all wonderful if a K3, or some other means, provides the TX frequency to the KAT500. The OP does not say he is using a K3 and does not say that any other frequency interface is being used.
>
>
> it was my assumption, based on the information in the first post, that RF sensing is being used and it is not working for the SSB phone signal.
>
>
> Andy, k3wyc
>
>
> ______________________________________________________________
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ANDY DURBIN

Re: KAT-500 auto-tuning issue with SSB vs. CW

In reply to this post by ANDY DURBIN

"when the KAT500 receives a burst of RF, it will tune to the remembered L/C combination for the frequency received, it will go immediately to that combination."

But the OP says it did not! It seems pointless to continue the discussion if you choose to completely disregard the problem the OP presented.

Andy, k3wyc

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k6dgw

Re: KAT-500 auto-tuning issue with SSB vs. CW

In reply to this post by Don Wilhelm

I will verify that this works exactly as Don relates. You must "train"
it by transmitting in every segment for each band/antenna combo you
have, but once trained, it's solid. The segments are small on 160 and 80
[10 KHz? I don't remember, someone on the list probably knows], and get
larger as you go up in frequency becoming 100 KHz or so at 10 m and
maybe twice that on 6. With the KAT500 in AUTO, tune to the center of
each segment, and press ATU TUNE if you have a K3, or just transmit if
you are using a non-Elecraft transceiver. It takes anywhere from 20 -
25 or so watts to tune.

Once you have hit every segment with every antenna that works on that
segment, switch to MAN and leave it there. The KAT500 utility will let
you specify which of the 3 antennas are usable on each band and won't
put others in the antenna selection cycle. To switch antennas, just tap
the button to get the desired antenna. The selection of tuning
parameters is as fast as it takes for the relays to close when you first
transmit. It worked fine for me when I still had my KAT500 on CW, SSB,
and RTTY. IMI: Operate in MAN, not AUTO.

If you have a K3/K3s and the cable between them installed and the KAT500
connected, the tuner will follow your receive QRG, selecting the correct
parameters as you tune, but the RF sense is nearly instantaneous without
the cable or a K3/K3s. IMI: Operate in MAN, not AUTO. Every time
someone has asked me to help them, and despite the "Operate in MAN, not
AUTO" advice from this list and others, I get there and find they're
operating in AUTO.

73,
Fred ["Skip"] K6DGW
Sparks NV DM09dn
Washoe County

On 11/19/2018 4:43 PM, Don Wilhelm wrote:

> The KAT500, will do the same for any transceiver - except for
> following the receive frequency.
> After training the tuner, when the KAT500 receives a burst of RF, it
> will tune to the remembered L/C combination for the frequency
> received, it will go immediately to that combination.
> Train in AUTO mode, then switch to MAN for reliable operation.
>
> 73,
> Don
> W3FPR

ANDY DURBIN

Re: KAT-500 auto-tuning issue with SSB vs. CW

In reply to this post by ANDY DURBIN

"The OP does not say he is using a K3"

I was mistaken. The OP does say he is using a K3S. However, the post does seem to suggest he is using RF sensing rather than direct frequency control.

Andy, k3wyc

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Elecraft mailing list

Re: KAT-500 auto-tuning issue with SSB vs. CW

In reply to this post by Elecraft mailing list

Thanks very much for all of the helpful and knowledgeable advice! I will do more reading in my Elecraft manuals and Cady books and adjust accordingly. This is a wonderful reflector!
The one additional complicating factor for me is that there are so many interfering objects close to my SteppIR beam and low (40 foot) tower that the antenna impedance changes pretty significantly as I rotate the beam. So a perfect solution (probably beyond my meager abilities) would require me to train my KAT-500 to recognize and adjust for various frequencies AND antenna headings.
Thanks again -
Rich, K1DJ

Sent from my iPad

> On Nov 19, 2018, at 5:28 AM, K1dj <[hidden email]> wrote:
>
> I am primarily a CW operator, but participated in the SSB Sweepstakes over this past weekend, running low power (100W) from my K3S, which runs through my KPA-500 and KAT-500 to a SteppIR 3-element beam with the 30/40 meter loop), a 40 meter wire dipole, and an 80 meter wire inverted V. During the contest, I repeatedly noticed that the KAT-500 was not re-tuning automatically to adjust to frequency changes based only on my SSB transmissions. But I found that if if I switched to CW for a couple of brief transmissions, the KAT-500 quickly re-tuned and reduced my SWR to near 1:1, so I could then switch back to SSB and complete the contact.
>
> [I retune the SteppIR manually as I change frequency, but the beam is only 40 feet up, and interacts with lots of trees, power lines, and other problematic structures close to my tiny 100 by 100 foot property, so the antenna itself is not always perfectly matched.]
>
> Has anybody experienced this problem or solved it?
>
> 73 -
> Rich, K1DJ
>
> Sent from my iPad

Don Wilhelm

Re: KAT-500 auto-tuning issue with SSB vs. CW

In reply to this post by ANDY DURBIN

Andy,

It does not make any difference whether he is using RF sensing or not.
Train the Tuner in AUTO, and then switch to MAN mode.

73,
Don W3FPR

On 11/19/2018 11:30 PM, ANDY DURBIN wrote:

> "The OP does not say he is using a K3"
>
>
> I was mistaken. The OP does say he is using a K3S. However, the post does seem to suggest he is using RF sensing rather than direct frequency control.
>
>
> Andy, k3wyc
>
>
>
>
> ______________________________________________________________
> Elecraft mailing list
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>
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Arthur Nienhouse

Re: KAT-500 auto-tuning issue with SSB vs. CW

*/Andy

Take this advice train the Tuner then run it in MAN mode I use my KPA500
and KAT500 with both a K3 and a IC7610 all I have to do when using the
Icom is tap the key in any mode send RF and the Tuner changes to the
memory it has in store for that segment of the band and antenna.

This is for the none Elecraft radios when using the Icom I *REMEMBER* to
have drive power set and the amp is in STBY. Set the KPA500 menu for
standby when power up or changing bands good insurance.
With the K3 the freq info is automatic ...again do not run the KTA500 in
AUTO mode it takes very little power for the tuner to see what is going on.

My reason for running it in MAN mode is if the weather changes my wire
antenna impedance Auto mode *might* try to re tune hot switching it.

Regards
Art
ka9zap
/*
On 11/20/2018 9:39 AM, Don Wilhelm wrote:

> Andy,
>
> It does not make any difference whether he is using RF sensing or not.
> Train the Tuner in AUTO, and then switch to MAN mode.
>
> 73,
> Don W3FPR
>
> On 11/19/2018 11:30 PM, ANDY DURBIN wrote:
>> "The OP does not say he is using a K3"
>>
>>
>> I was mistaken. The OP does say he is using a K3S. However, the post
>> does seem to suggest he is using RF sensing rather than direct
>> frequency control.
>>
>>
>> Andy, k3wyc

ANDY DURBIN

Re: KAT-500 auto-tuning issue with SSB vs. CW

In reply to this post by Don Wilhelm

"It does not make any difference whether he is using RF sensing or not."

Don,

Since I have trained my KAT500, I had assumed the OP had done that as well. I was thinking that the problem was that the SSB phone transmission was not causing the KAT500 to switch to the memorized tuning solution. I can see now that I had misunderstood the problem.

I never use my KAT500 in any mode except MANUAL. AUTO takes control away from me and, in BYPASS mode, memorized antenna selections do not work correctly.

In my station my KAT500 and my SteppIR follow the transmit frequency of my TS-590. This avoids any re-configuration at start of TX for cases where TX and RX frequencies are not equal.

73,

Andy, k3wyc

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Elecraft mailing list

Re: KAT-500 auto-tuning issue with SSB vs. CW

K3 + KAT500 via Aux Bus

1 - Train the KAT500
2 - Switch to Manual Mode
3 - Turn on K3 frequency tracking. CONFIG:KAT3 tap "1" to KAT500Y.

GL - Steve WB6RSE
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