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KAT3A Question

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stengrevics

KAT3A Question

My 6 meter antenna reads an SWR of 10:1 on 10 meters. The KAT3A specs suggest it can tune that degree of mismatch. Is it reasonable to think that the KAT3A could match my antenna well enough for 10 meters?

Thanks & 73,

John
WA1EAZ
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Don Wilhelm

Re: KAT3A Question

Why don't you tap the ATU TUNE button and see what happens?

73,
Don W3FPR

On 4/11/2020 5:06 PM, John Stengrevics wrote:
> My 6 meter antenna reads an SWR of 10:1 on 10 meters. The KAT3A specs suggest it can tune that degree of mismatch. Is it reasonable to think that the KAT3A could match my antenna well enough for 10 meters?
>
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stengrevics

Re: KAT3A Question

I would if I had one! 😁

73,

John
WA1EAZ

> On Apr 11, 2020, at 5:15 PM, Don Wilhelm <[hidden email]> wrote:
>
> Why don't you tap the ATU TUNE button and see what happens?
>
> 73,
> Don W3FPR
>
> On 4/11/2020 5:06 PM, John Stengrevics wrote:
>> My 6 meter antenna reads an SWR of 10:1 on 10 meters. The KAT3A specs suggest it can tune that degree of mismatch. Is it reasonable to think that the KAT3A could match my antenna well enough for 10 meters?

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Nr4c

Re: KAT3A Question

In reply to this post by stengrevics

Why not try it.

The KAT3(a) can tune many a strange antenna.

It seems so easy to hook up the antenna and tap the button to see if it works instead of typing a query here and getting many responses. A lot of which will suggest “Try it and see. “

Good luck.

Sent from my iPhone
...nr4c. bill

> On Apr 11, 2020, at 5:08 PM, John Stengrevics <[hidden email]> wrote:
>
> My 6 meter antenna reads an SWR of 10:1 on 10 meters. The KAT3A specs suggest it can tune that degree of mismatch. Is it reasonable to think that the KAT3A could match my antenna well enough for 10 meters?
>
> Thanks & 73,
>
> John
> WA1EAZ
> ______________________________________________________________
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Nr4c

Re: KAT3A Question

In reply to this post by Don Wilhelm

What’d I tell you?

Sent from my iPhone
...nr4c. bill

> On Apr 11, 2020, at 5:17 PM, Don Wilhelm <[hidden email]> wrote:
>
> Why don't you tap the ATU TUNE button and see what happens?
>
> 73,
> Don W3FPR
>
>> On 4/11/2020 5:06 PM, John Stengrevics wrote:
>> My 6 meter antenna reads an SWR of 10:1 on 10 meters. The KAT3A specs suggest it can tune that degree of mismatch. Is it reasonable to think that the KAT3A could match my antenna well enough for 10 meters?
> ______________________________________________________________
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stengrevics

Re: KAouT3A Question

In reply to this post by Nr4c

If I had one, I would certainly give it a try! I am trying to decide if I should buy one.

John
WA1EAZ

> On Apr 11, 2020, at 8:23 PM, Nr4c <[hidden email]> wrote:
>
> Why not try it.
>
> The KAT3(a) can tune many a strange antenna.
>
> It seems so easy to hook up the antenna and tap the button to see if it works instead of typing a query here and getting many responses. A lot of which will suggest “Try it and see. “
>
> Good luck.
>
>
>
> Sent from my iPhone
> ...nr4c. bill
>
>
>> On Apr 11, 2020, at 5:08 PM, John Stengrevics <[hidden email]> wrote:
>>
>> My 6 meter antenna reads an SWR of 10:1 on 10 meters. The KAT3A specs suggest it can tune that degree of mismatch. Is it reasonable to think that the KAT3A could match my antenna well enough for 10 meters?
>>
>> Thanks & 73,
>>
>> John
>> WA1EAZ
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
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>>
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Bob McGraw - K4TAX

Re: KAT3A Question

In reply to this post by stengrevics

My 6M yagi shows a 5.3:1 SWR as indicated on my K3S on 28.3MHz with the
ATU in Bypass mode. When the KAT3A ATU in the radio resolves a match,
the indicated SWR indicated is 1.1:1 on the radio.

Using the same antenna but using my KAT500 ATU the best SWR resolved is
1.6:1 as indicated on the radio.

Now my antenna analyzer on 28.3 MHz with my 6M yagi connected shows and
SWR of 7.5:1, a Z value of 16.6 ohms, and R value of 7.3 ohms and the X
value of 14.7.

That same antenna on the analyzer at 50.2MHz shows the SWR at 1.2:1, Z
at 39.9, R at 40.0 and Z at 0.0

My conclusion: although the SWR values may be indicating acceptable
values, the 6 meter Yagi operated on 10 meters would make a very lousy
antenna. You'd be much better off to use an 80 meter dipole or better
yet, just a 10 meter dipole.

73

Bob, K4TAX

On 4/11/2020 4:06 PM, John Stengrevics wrote:

> My 6 meter antenna reads an SWR of 10:1 on 10 meters. The KAT3A specs suggest it can tune that degree of mismatch. Is it reasonable to think that the KAT3A could match my antenna well enough for 10 meters?
>
> Thanks & 73,
>
> John
> WA1EAZ
> ______________________________________________________________
> Elecraft mailing list
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>

Nr4c

Re: KAT3A Question

In reply to this post by stengrevics

So you’re questioning whether you should buy one?

Might have made that clear in your query.

Yes. No K3(S) should exist without the appropriate KAT3(a).

Sent from my iPhone
...nr4c. bill

> On Apr 11, 2020, at 5:32 PM, John Stengrevics <[hidden email]> wrote:
>
> I would if I had one! 😁
>
> 73,
>
> John
> WA1EAZ
>
>> On Apr 11, 2020, at 5:15 PM, Don Wilhelm <[hidden email]> wrote:
>>
>> Why don't you tap the ATU TUNE button and see what happens?
>>
>> 73,
>> Don W3FPR
>>
>>> On 4/11/2020 5:06 PM, John Stengrevics wrote:
>>> My 6 meter antenna reads an SWR of 10:1 on 10 meters. The KAT3A specs suggest it can tune that degree of mismatch. Is it reasonable to think that the KAT3A could match my antenna well enough for 10 meters?
>
> ______________________________________________________________
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john@kk9a.com

Re: KAT3A Question

In reply to this post by stengrevics

If you're trying to figure out if you should purchase a KAT3A, you cannot buy one from Elecraft.

John KK9A

John Stengrevics WA1EAZ wrote:

I would if I had one! 😁

73,

John
WA1EAZ

> On Apr 11, 2020, at 5:15 PM, Don Wilhelm <donwilh at embarqmail.com> wrote:
>
> Why don't you tap the ATU TUNE button and see what happens?
>
> 73,
> Don W3FPR
>
> On 4/11/2020 5:06 PM, John Stengrevics wrote:
>> My 6 meter antenna reads an SWR of 10:1 on 10 meters. The KAT3A specs suggest it can tune that degree of mismatch. Is it reasonable to think that the KAT3A could match my antenna well enough for 10 meters?

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Mark Goldberg

Re: KAT3A Question

In reply to this post by Bob McGraw - K4TAX

On Sat, Apr 11, 2020 at 6:09 PM Bob McGraw K4TAX <[hidden email]>
wrote:

> My 6M yagi shows a 5.3:1 SWR as indicated on my K3S on 28.3MHz with the
> ATU in Bypass mode. When the KAT3A ATU in the radio resolves a match,
> the indicated SWR indicated is 1.1:1 on the radio.
>
> Using the same antenna but using my KAT500 ATU the best SWR resolved is
> 1.6:1 as indicated on the radio.
>
> Now my antenna analyzer on 28.3 MHz with my 6M yagi connected shows and
> SWR of 7.5:1, a Z value of 16.6 ohms, and R value of 7.3 ohms and the X
> value of 14.7.
>
> That same antenna on the analyzer at 50.2MHz shows the SWR at 1.2:1, Z
> at 39.9, R at 40.0 and Z at 0.0
>
> My conclusion: although the SWR values may be indicating acceptable
> values, the 6 meter Yagi operated on 10 meters would make a very lousy
> antenna. You'd be much better off to use an 80 meter dipole or better
> yet, just a 10 meter dipole.
>

In addition, a Yagi operated at a non resonant frequency, especially below
it's design frequency is likely to not act like a Yagi at all. The pattern
depends on the elements being close to resonance. More wire / aluminum is
usually better. A physically short antenna may be tunable but it won't be
efficient. Much of the power will be dissipated in the tuner or balun or
feedline as losses. A physically short antenna + tuner + high power often
results in smoke somewhere! I use a 300 foot horizontal look and it can be
tuned from 80 to 6 meters. Who knows what the pattern is at high
frequencies but I can make contacts!

So, a tuner is a good idea, but it won't solve every problem. Because it is
easy to understand, Hams use SWR, but in actuality the same number for SWR
results from an infinite number of impedances ( R and X), not all of which
can be handled by the tuner the same way. ARRL has done some comparison
testing with tuners with various impedances, I believe. I don't know if the
losses have been measured, but you can take two different impedances that
result in an SWR of 4:1 and only some can be tuned, depending on the tuner.

73,

Mark
W7MLG
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Tox

Re: KAT3A Question

Ft-991 (pre-A samples at least) has trouble tuning some multitrap verticals
for all the expected bands, this may explain why

On Sat, Apr 11, 2020, 7:57 PM Mark Goldberg <[hidden email]> wrote:

> On Sat, Apr 11, 2020 at 6:09 PM Bob McGraw K4TAX <[hidden email]>
> wrote:
>
> > My 6M yagi shows a 5.3:1 SWR as indicated on my K3S on 28.3MHz with the
> > ATU in Bypass mode. When the KAT3A ATU in the radio resolves a match,
> > the indicated SWR indicated is 1.1:1 on the radio.
> >
> > Using the same antenna but using my KAT500 ATU the best SWR resolved is
> > 1.6:1 as indicated on the radio.
> >
> > Now my antenna analyzer on 28.3 MHz with my 6M yagi connected shows and
> > SWR of 7.5:1, a Z value of 16.6 ohms, and R value of 7.3 ohms and the X
> > value of 14.7.
> >
> > That same antenna on the analyzer at 50.2MHz shows the SWR at 1.2:1, Z
> > at 39.9, R at 40.0 and Z at 0.0
> >
> > My conclusion: although the SWR values may be indicating acceptable
> > values, the 6 meter Yagi operated on 10 meters would make a very lousy
> > antenna. You'd be much better off to use an 80 meter dipole or better
> > yet, just a 10 meter dipole.
> >
>
> In addition, a Yagi operated at a non resonant frequency, especially below
> it's design frequency is likely to not act like a Yagi at all. The pattern
> depends on the elements being close to resonance. More wire / aluminum is
> usually better. A physically short antenna may be tunable but it won't be
> efficient. Much of the power will be dissipated in the tuner or balun or
> feedline as losses. A physically short antenna + tuner + high power often
> results in smoke somewhere! I use a 300 foot horizontal look and it can be
> tuned from 80 to 6 meters. Who knows what the pattern is at high
> frequencies but I can make contacts!
>
> So, a tuner is a good idea, but it won't solve every problem. Because it is
> easy to understand, Hams use SWR, but in actuality the same number for SWR
> results from an infinite number of impedances ( R and X), not all of which
> can be handled by the tuner the same way. ARRL has done some comparison
> testing with tuners with various impedances, I believe. I don't know if the
> losses have been measured, but you can take two different impedances that
> result in an SWR of 4:1 and only some can be tuned, depending on the tuner.
>
> 73,
>
> Mark
> W7MLG
> ______________________________________________________________
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> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]
>

Jim Brown-10

Re: KAT3A Question

On 4/11/2020 8:14 PM, Tox wrote:
> Ft-991 (pre-A samples at least) has trouble tuning some multitrap verticals
> for all the expected bands, this may explain why

The things we call "antenna tuners" do nothing at all to the antenna.
Rather, they are an adjustable network that we adjust so that the rig
(or power amp) supplies power to the transmission line, and so that the
output stage is "happy." In this context, "happy" means that the output
stage is operating in a "safe" region (not likely to overheat or fail),
and that it is producing minimum distortion.

If the antenna is poorly matched to the line, there are standing waves,
increasing the loss in the line, so less of that power gets to the antenna.

The fact that a radio doesn't work with a multi-band vertical says more
far about the multi-band vertical than it does about the radio. Perhaps
it was assembled badly, was damaged in some way, lacked radials (if a
type that needs radials), or was installed in proximity to a vertical
metallic object. Or the feedline was defective.

On 4/11/2020 7:57 PM, Mark Goldberg wrote:
> In addition, a Yagi operated at a non resonant frequency, especially
below
> it's design frequency is likely to not act like a Yagi at all. The
pattern
> depends on the elements being close to resonance.

Right. ALL antenna arrays (that is, those with multiple elements) only
work at their design frequency, or a narrow band around that frequency.
That's because they work on the basis of their electrical length in
degrees, and the electrical distance in degrees between the elements. So
that 10M Yagi is nothing more than a non-resonant dipole with a random
bunch of aluminum around it.

SWR is DEFINED by the match between the antenna and the line, and that
SWR causes additional loss. This loss causes the SWR to get smaller
along the line moving in the direction of the transmitter. When an SWR
bridge in the shack reads 5:1, the SWR at the antenna could be 10:1,
depending on the loss characteristics of the line and its length)!

So the antenna tuner does nothing to change the SWR or the antenna.

73, Jim K9YC

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Tox

Re: KAT3A Question

Specifically, multiple samples of ft-991 owned by different operators would
"autotune" optimally poorly ( resulting in a 99:1 on a 6-10:1 feed?)
against multiple samples of, iirc, 4BTV. I suspect software bugs may play a
part as well. *Shrug*

I haven't operated my 991 since, instead use my kx3 as my shack radio until
my k4 arrives. Returned the 4btv to the gentleman that was kind enough to
loan it to me, have a 6btv(?) awaiting erection but have been getting by
with a fan dipole, reducing urgency. Have no idea what the other owner I
was talking to at the Yaesu booth did about his.

AD6YT

On Sat, Apr 11, 2020, 11:56 PM Jim Brown <[hidden email]> wrote:

> On 4/11/2020 8:14 PM, Tox wrote:
> > Ft-991 (pre-A samples at least) has trouble tuning some multitrap
> verticals
> > for all the expected bands, this may explain why
>
> The things we call "antenna tuners" do nothing at all to the antenna.
> Rather, they are an adjustable network that we adjust so that the rig
> (or power amp) supplies power to the transmission line, and so that the
> output stage is "happy." In this context, "happy" means that the output
> stage is operating in a "safe" region (not likely to overheat or fail),
> and that it is producing minimum distortion.
>
> If the antenna is poorly matched to the line, there are standing waves,
> increasing the loss in the line, so less of that power gets to the antenna.
>
> The fact that a radio doesn't work with a multi-band vertical says more
> far about the multi-band vertical than it does about the radio. Perhaps
> it was assembled badly, was damaged in some way, lacked radials (if a
> type that needs radials), or was installed in proximity to a vertical
> metallic object. Or the feedline was defective.
>
> On 4/11/2020 7:57 PM, Mark Goldberg wrote:
> > In addition, a Yagi operated at a non resonant frequency, especially
> below
> > it's design frequency is likely to not act like a Yagi at all. The
> pattern
> > depends on the elements being close to resonance.
>
> Right. ALL antenna arrays (that is, those with multiple elements) only
> work at their design frequency, or a narrow band around that frequency.
> That's because they work on the basis of their electrical length in
> degrees, and the electrical distance in degrees between the elements. So
> that 10M Yagi is nothing more than a non-resonant dipole with a random
> bunch of aluminum around it.
>
> SWR is DEFINED by the match between the antenna and the line, and that
> SWR causes additional loss. This loss causes the SWR to get smaller
> along the line moving in the direction of the transmitter. When an SWR
> bridge in the shack reads 5:1, the SWR at the antenna could be 10:1,
> depending on the loss characteristics of the line and its length)!
>
> So the antenna tuner does nothing to change the SWR or the antenna.
>
> 73, Jim K9YC
>
> ______________________________________________________________
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>

Wes Stewart-2

Re: KAT3A Question

In reply to this post by Nr4c

Really? Mine doesn't and it doesn't have a 2nd RX either, something that
everyone "knows" you have to have to work DX.

Wes N7WS
DXCC Honor Roll and 9-band DXCC (All from the same city)

On 4/11/2020 6:12 PM, Nr4c wrote:
>
> Yes. No K3(S) should exist without the appropriate KAT3(a).
>

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john@kk9a.com

Re: KAT3A Question

In reply to this post by stengrevics

It was a $400 option and unnecessary with resonant antennas. I have three
Elecraft K3S's and none of them have KAT3A tuners.

John KK9A

Nr4c wrote

<snip> No K3(S) should exist without the appropriate KAT3(a).

Sent from my iPhone
...nr4c. bill

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Nr4c

Re: KAT3A Question

For station use at home I could get by without. But my radios are used for many club/portable events and antennas are often not optimal. So a ATU is helpful.

And I figure if I ever want to sell it it might bring either higher price or quicker sale.

Sent from my iPhone
...nr4c. bill

> On Apr 12, 2020, at 11:19 AM, [hidden email] wrote:
>
> It was a $400 option and unnecessary with resonant antennas. I have three
> Elecraft K3S's and none of them have KAT3A tuners.
>
>
> John KK9A
>
>
> Nr4c wrote
>
> <snip> No K3(S) should exist without the appropriate KAT3(a).
>
>
>
> Sent from my iPhone
> ...nr4c. bill
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
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>
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