Re: [Elecraft] Antenna Quandary

[Jim Brown]

On 5/12/2022 3:08 PM, Ed Cole wrote:

I have ends supported with nylon cord over pulleys to lower for cutting.


Yes, and it's a MUST for any wire where one or both ends are rigged to a 
tree with one end tied to a weight to allow for tree sway in the wind. 
K2RD showed me how to do that without hiring a climber. I use big water 
jugs filled with dry sand for the 90-100# needed for dipoles at 100-130 
ft in my redwoods; others use suitably sized concrete blocks or hooks 
set in concrete poured into a bucket; window sash weights work for lower 
antennas that don't need as much tension to support the feedline.


73, Jim K9YC
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Re: [Elecraft] Antenna Quandary

[Ed Cole]

Unbelievable answers (really).

If someone asked if anyone was knowledgeable about contesting or say 
eme, would you just answer yes or no? Or would you offer assistance to 
the questioner?


My first ham antenna was a folded dipole for 40m.  It was described in 
my first ARRL Handbook as there were no nearby hams to ask and in 1958 
there was no internet.  TV twinlead was locally available so was easier 
to make than one requiring coax.  I soldered a PL-259 directly the 
twinlead feedline and connected to my DX-35  (which loaded it FB even 
with high SWR that, at age 14, I was unaware of).


For HF half-wave, center-fed, dipoles have been my favorite.  Currently 
have a 80/40M inverted-V (fan-style).  Wire lengths slightly longer for 
resonance than for horizontal dipole.  Cut slightly longer than formula 
(492/F) and trim until SWR matched.  I have ends supported with nylon 
cord over pulleys to lower for cutting.


73, Ed - KL7UW
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Re: [Elecraft] Antenna Quandary

[Jim Brown]

On 5/11/2022 10:20 PM, Jim Brown wrote:
Low dipoles are closer to 50 ohms, high dipoles are closer to 75 ohms. 
Low would be much less than a quarter wave, high would be much more than 
a quarter wave.


BTW -- there are a couple of very useful graphics that help understand 
this at the beginning of Chapter 8 of ON4UN's "Low Band DXing," another 
great antenna book published by ARRL.  One shows the ground reflection 
as a mirror, the other, paragraph 1.3.1 in my 20 year old edition, shows 
how feedpoint R and X vary with height for an 80M dipole. Ground 
conductivity is not shown, so I'm guessing it's computed for average 
ground.


And I agree with W4TV about the usefulness of the Antenna Book. I 
contribute both to it and to the Handbook. These three ARRL books have 
been central to my learning, in some ways, at least as important as my 
EE education.


73, Jim K9YC


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Re: [Elecraft] Antenna Quandary

[Jim Brown]

On 5/11/2022 6:51 PM, Richard wrote:

Jim —

I just finished building a half-wave 40-meter dipole and have it nicely 
tuned for the middle of the SSB segment. Out of necessity, the tuning 
process was carried out with the antenna horizontal.


Feedpoint Z of horizontal antennas is slightly affected by height and 
surrounding objects, so ideally should be tune at the rigged height, 
then lowered and re-adjusted if necessary.


*QUESTION 1:* Should I ever hang this antenna as an inverted V, would 
that result in a significant change to the location of the sweet spot?


Slightly.


When we finally got the leg lengths to the point where the SSB sweet 
spot was damn near perfect, we had folded back 30 inches of excess leg 
wire on each leg. The excess was not twisted around the legs but instead 
laid parallel to the leg wires and Gorilla taped in place in several places.


Remember that SWR is NOT a measure of antenna performance, it only tells 
us approximately where it is resonant. That's because the feedpoint 
impedance varies a bit with height, thanks to the reflection from the 
ground coupling back to the antenna.


Folding it back as you have done is perfectly good technique -- the 
antenna ends at the fold (that is, where it goes through the insulator. 
We routinely do that when rigging new wires.


*QUESTION B:* I’d like to cut off 12 of the 30 inches of excess wire, 
leaving 18 inches in case I or some future owner wants to retune down to 
the CW segment. Will shortening the excess wire from 30 to 18 inches 
influence the sweet spot?


SWR matters two ways. First, the match at the transmitter must be good 
enough that the transmitter can put full power into it. Additional loss 
due to SWR doesn't matter much until the SWR gets pretty high unless 
you're using small diameter coax or it's a long length of coax. As long 
as you have an antenna tuner (really an adjustable network to match the 
transmission line to the rig), any SWR below about 2.5:1 is plenty good 
enough unless the line is long enough, or small enough diameter, to have 
a lot of loss. That's why smart hams use big coax like RG8 or RG11 to 
feed dipoles. Low dipoles are closer to 50 ohms, high dipoles are closer 
to 75 ohms. Low would be much less than a quarter wave, high would be 
much more than a quarter wave. That feedpoint Z also depends on ground 
conductivity.


SO -- since the full width of 40M is a small as a percentage of the 
frequency, so a half-wave dipole cut for 7150 will be just fine to cover 
from 7,000 - 7,300 kHz. Ditto for all the bands above 40M until you hit 
10M, but even there, unless you work FM, which is at the top of the 
band, a dipole tuned to about 28.45 MHz will be "good enough" for where 
all the action is.


BTW -- as study all this stuff and learn to use the tools, there is 
antenna modeling software that will let you learn by modeling.


Here's a study I did several years ago on the effect of antenna height 
both as text and slides.

http://k9yc.com/AntennaPlanning.pdf
http://k9yc.com/VertOrHorizontal-Slides.pdf

73, Jim K9YC


Looking forward to your input.

Cheers.

Richard

That said, what's your question? OF COURSE there are LOTS of folks 
here who know a LOT about half wave dipoles. I have six of them in the 
air for different bands and directions.


73, Jim K9YC


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Re: [Elecraft] Antenna Quandary

[Richard Eversole]

Wa

Half wave




On Wed, May 11, 2022, 20:09 Hank via Elecraft 
wrote:

> I wish I knew as much about half wave dipoles as I think I do.
>
> Hank
> K4HYJ
>
> > On May 11, 2022, at 10:52 PM, Edward Mccann  wrote:
> >
> > Concur.
> >
> > Slack reasonable cut.
> >
> > No dumb questions, just dumb answers, from time to time.
> >
> > But I’m amazed at the restraint shown by many who are avoiding the tithe
> of arms-appointed expert, especially when we have a passel of Big Swinging
> Dudes on the line.
> >
> > The query might have been a bit more foucssed, or tailored to the K
> line. But maybe Santa Cruz has a proprietary dipole in the back room I
> missed.
> >
> > 73,
> >
> > Ed McCann
> > AG6CX
> >
> > Sent from my iPhone
> >
> > On May 11, 2022, at 7:37 PM, Gwen Patton  wrote:
> >
> > *"On the other hand, cutting the guy some slack is ok too. This is a
> tough
> > room but the only dumb question is the one you don’t ask."*
> >
> > I dunno... "Is the Pink Panther a lion" is up there in essential
> dumbitude.
> >
> > https://youtu.be/J0UVlPmhY0A
> >
> > 73,
> > Gwen, NG3P
> >
> >> On Wed, May 11, 2022, 10:20 PM Lou Laderman via Elecraft <
> >> elecraft@mailman.qth.net> wrote:
> >>
> >> On the other hand, cutting the guy some slack is ok too. This is a tough
> >> room but the only dumb question is the one you don’t ask.
> >>
> >> 73, Lou W0FK
> >>
> >> Lou Laderman
> >> Sent from my mobile device
> >>
> >> On May 11, 2022, at 9:09 PM, Edward Mccann  wrote:
> >>
> >> Entirely possible this is a late April Fool’s query, or a freshman
> >> fraternity prank designed to bring out the blowhards who will profess
> >> knowledge of most things.
> >>
> >> When and if the  query is expanded to source commentary from those
> >> “super-well versed” in the behavior of the OCFD,  from under the rock
> will
> >> come more than you ever bargained for.
> >>
> >> 73,
> >>
> >> Ed McCann
> >> AG6CX
> >>
> >> Sent from my iPhone
> >>
> >> On May 11, 2022, at 6:39 PM, Andy Durbin  wrote:
> >>
> >> "Anybody out there super-well versed in the behavior of the half-wave
> >> dipole?"
> >>
> >> There are only two possible answers:
> >>
> >> Yes
> >> No
> >>
> >> I speculate that, given the expertise of this group, "Yes" is the right
> >> answer.  However, I have no clue how the answer to your question will be
> >> useful to you.
> >>
> >> I suppose the resulting answers may be more informative than "why didn't
> >> my package carrier meet my expectations?".
> >>
> >> Andy, k3wyc
> >>
> >> __
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Re: [Elecraft] Antenna Quandary

[Hank via Elecraft]

I wish I knew as much about half wave dipoles as I think I do. 

Hank
K4HYJ 

> On May 11, 2022, at 10:52 PM, Edward Mccann  wrote:
> 
> Concur.
> 
> Slack reasonable cut.
> 
> No dumb questions, just dumb answers, from time to time.
> 
> But I’m amazed at the restraint shown by many who are avoiding the tithe of 
> arms-appointed expert, especially when we have a passel of Big Swinging Dudes 
> on the line.
> 
> The query might have been a bit more foucssed, or tailored to the K line. But 
> maybe Santa Cruz has a proprietary dipole in the back room I missed.
> 
> 73,
> 
> Ed McCann
> AG6CX
> 
> Sent from my iPhone
> 
> On May 11, 2022, at 7:37 PM, Gwen Patton  wrote:
> 
> *"On the other hand, cutting the guy some slack is ok too. This is a tough
> room but the only dumb question is the one you don’t ask."*
> 
> I dunno... "Is the Pink Panther a lion" is up there in essential dumbitude.
> 
> https://youtu.be/J0UVlPmhY0A
> 
> 73,
> Gwen, NG3P
> 
>> On Wed, May 11, 2022, 10:20 PM Lou Laderman via Elecraft <
>> elecraft@mailman.qth.net> wrote:
>> 
>> On the other hand, cutting the guy some slack is ok too. This is a tough
>> room but the only dumb question is the one you don’t ask.
>> 
>> 73, Lou W0FK
>> 
>> Lou Laderman
>> Sent from my mobile device
>> 
>> On May 11, 2022, at 9:09 PM, Edward Mccann  wrote:
>> 
>> Entirely possible this is a late April Fool’s query, or a freshman
>> fraternity prank designed to bring out the blowhards who will profess
>> knowledge of most things.
>> 
>> When and if the  query is expanded to source commentary from those
>> “super-well versed” in the behavior of the OCFD,  from under the rock will
>> come more than you ever bargained for.
>> 
>> 73,
>> 
>> Ed McCann
>> AG6CX
>> 
>> Sent from my iPhone
>> 
>> On May 11, 2022, at 6:39 PM, Andy Durbin  wrote:
>> 
>> "Anybody out there super-well versed in the behavior of the half-wave
>> dipole?"
>> 
>> There are only two possible answers:
>> 
>> Yes
>> No
>> 
>> I speculate that, given the expertise of this group, "Yes" is the right
>> answer.  However, I have no clue how the answer to your question will be
>> useful to you.
>> 
>> I suppose the resulting answers may be more informative than "why didn't
>> my package carrier meet my expectations?".
>> 
>> Andy, k3wyc
>> 
>> __
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Re: [Elecraft] Antenna Quandary

[Edward Mccann]

Concur.

Slack reasonable cut.

No dumb questions, just dumb answers, from time to time.

But I’m amazed at the restraint shown by many who are avoiding the tithe of 
arms-appointed expert, especially when we have a passel of Big Swinging Dudes 
on the line.

The query might have been a bit more foucssed, or tailored to the K line. But 
maybe Santa Cruz has a proprietary dipole in the back room I missed.

73,

Ed McCann
AG6CX

Sent from my iPhone

On May 11, 2022, at 7:37 PM, Gwen Patton  wrote:

*"On the other hand, cutting the guy some slack is ok too. This is a tough
room but the only dumb question is the one you don’t ask."*

I dunno... "Is the Pink Panther a lion" is up there in essential dumbitude.

https://youtu.be/J0UVlPmhY0A

73,
Gwen, NG3P

On Wed, May 11, 2022, 10:20 PM Lou Laderman via Elecraft <
elecraft@mailman.qth.net> wrote:

> On the other hand, cutting the guy some slack is ok too. This is a tough
> room but the only dumb question is the one you don’t ask.
> 
> 73, Lou W0FK
> 
> Lou Laderman
> Sent from my mobile device
> 
> On May 11, 2022, at 9:09 PM, Edward Mccann  wrote:
> 
> Entirely possible this is a late April Fool’s query, or a freshman
> fraternity prank designed to bring out the blowhards who will profess
> knowledge of most things.
> 
> When and if the  query is expanded to source commentary from those
> “super-well versed” in the behavior of the OCFD,  from under the rock will
> come more than you ever bargained for.
> 
> 73,
> 
> Ed McCann
> AG6CX
> 
> Sent from my iPhone
> 
> On May 11, 2022, at 6:39 PM, Andy Durbin  wrote:
> 
> "Anybody out there super-well versed in the behavior of the half-wave
> dipole?"
> 
> There are only two possible answers:
> 
> Yes
> No
> 
> I speculate that, given the expertise of this group, "Yes" is the right
> answer.  However, I have no clue how the answer to your question will be
> useful to you.
> 
> I suppose the resulting answers may be more informative than "why didn't
> my package carrier meet my expectations?".
> 
> Andy, k3wyc
> 
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Re: [Elecraft] Antenna Quandary

[john]

Mine is well-behaved.



On 5/11/2022 1:56 PM, Richard W4KBX wrote:

> Anybody out there super-well versed in the behavior of the half-wave
dipole?
>
> Cheers,
>
> Richard Kunc
> W4KBX

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Re: [Elecraft] Antenna Quandary

[Gwen Patton]

*"On the other hand, cutting the guy some slack is ok too. This is a tough
room but the only dumb question is the one you don’t ask."*

I dunno... "Is the Pink Panther a lion" is up there in essential dumbitude.

https://youtu.be/J0UVlPmhY0A

73,
Gwen, NG3P

On Wed, May 11, 2022, 10:20 PM Lou Laderman via Elecraft <
elecraft@mailman.qth.net> wrote:

> On the other hand, cutting the guy some slack is ok too. This is a tough
> room but the only dumb question is the one you don’t ask.
>
> 73, Lou W0FK
>
> Lou Laderman
> Sent from my mobile device
>
> On May 11, 2022, at 9:09 PM, Edward Mccann  wrote:
>
> Entirely possible this is a late April Fool’s query, or a freshman
> fraternity prank designed to bring out the blowhards who will profess
> knowledge of most things.
>
> When and if the  query is expanded to source commentary from those
> “super-well versed” in the behavior of the OCFD,  from under the rock will
> come more than you ever bargained for.
>
> 73,
>
> Ed McCann
> AG6CX
>
> Sent from my iPhone
>
> On May 11, 2022, at 6:39 PM, Andy Durbin  wrote:
>
> "Anybody out there super-well versed in the behavior of the half-wave
> dipole?"
>
> There are only two possible answers:
>
> Yes
> No
>
> I speculate that, given the expertise of this group, "Yes" is the right
> answer.  However, I have no clue how the answer to your question will be
> useful to you.
>
> I suppose the resulting answers may be more informative than "why didn't
> my package carrier meet my expectations?".
>
> Andy, k3wyc
>
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Re: [Elecraft] Antenna Quandary

[Lou Laderman via Elecraft]

On the other hand, cutting the guy some slack is ok too. This is a tough room 
but the only dumb question is the one you don’t ask. 

73, Lou W0FK

Lou Laderman 
Sent from my mobile device 

On May 11, 2022, at 9:09 PM, Edward Mccann  wrote:

Entirely possible this is a late April Fool’s query, or a freshman fraternity 
prank designed to bring out the blowhards who will profess knowledge of most 
things.

When and if the  query is expanded to source commentary from those  “super-well 
versed” in the behavior of the OCFD,  from under the rock will come more than 
you ever bargained for.

73,

Ed McCann
AG6CX

Sent from my iPhone

On May 11, 2022, at 6:39 PM, Andy Durbin  wrote:

"Anybody out there super-well versed in the behavior of the half-wave dipole?"

There are only two possible answers:

Yes
No

I speculate that, given the expertise of this group, "Yes" is the right answer. 
 However, I have no clue how the answer to your question will be useful to you.

I suppose the resulting answers may be more informative than "why didn't my 
package carrier meet my expectations?".

Andy, k3wyc

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Re: [Elecraft] Antenna Quandary

[Edward Mccann]

Entirely possible this is a late April Fool’s query, or a freshman fraternity 
prank designed to bring out the blowhards who will profess knowledge of most 
things.

When and if the  query is expanded to source commentary from those  “super-well 
versed” in the behavior of the OCFD,  from under the rock will come more than 
you ever bargained for.

73,

Ed McCann
AG6CX

Sent from my iPhone

On May 11, 2022, at 6:39 PM, Andy Durbin  wrote:

"Anybody out there super-well versed in the behavior of the half-wave dipole?"

There are only two possible answers:

Yes
No

I speculate that, given the expertise of this group, "Yes" is the right answer. 
 However, I have no clue how the answer to your question will be useful to you.

I suppose the resulting answers may be more informative than "why didn't my 
package carrier meet my expectations?".

Andy, k3wyc

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Re: [Elecraft] Antenna Quandary

[Andy Durbin]

"Anybody out there super-well versed in the behavior of the half-wave dipole?"

There are only two possible answers:

Yes
No

I speculate that, given the expertise of this group, "Yes" is the right answer. 
 However, I have no clue how the answer to your question will be useful to you.

I suppose the resulting answers may be more informative than "why didn't my 
package carrier meet my expectations?".

Andy, k3wyc

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Re: [Elecraft] Antenna Quandary

[Joe Subich, W4TV]

On 2022-05-11 8:02 PM, Jim Brown wrote:
> On 5/11/2022 1:56 PM, Richard wrote:
>> Anybody out there super-well versed in the behavior of the half-wave
>> dipole?
>
> You do have a copy of the ARRL Handbook, don't you? Every ham should
> have one, and there's a lot of tutorial material in it.

Two books no amateur's library should be without: the ARRL Handbook
and the ARRL Antenna Manual.  The Antenna Manual is the far better
reference for questions about a half-wave dipole.

73,

   ... Joe, W4TV


On 2022-05-11 8:02 PM, Jim Brown wrote:

On 5/11/2022 1:56 PM, Richard wrote:
Anybody out there super-well versed in the behavior of the half-wave 
dipole?


You do have a copy of the ARRL Handbook, don't you? Every ham should 
have one, and there's a lot of tutorial material in it. I'd bet that 
every single one of those engineers who got us to the moon learned 
electronics and radio from The Handbook.


That said, what's your question? OF COURSE there are LOTS of folks here 
who know a LOT about half wave dipoles. I have six of them in the air 
for different bands and directions.


73, Jim K9YC



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Re: [Elecraft] Antenna Quandary

[Jim Brown]

On 5/11/2022 1:56 PM, Richard wrote:

Anybody out there super-well versed in the behavior of the half-wave dipole?


You do have a copy of the ARRL Handbook, don't you? Every ham should 
have one, and there's a lot of tutorial material in it. I'd bet that 
every single one of those engineers who got us to the moon learned 
electronics and radio from The Handbook.


That said, what's your question? OF COURSE there are LOTS of folks here 
who know a LOT about half wave dipoles. I have six of them in the air 
for different bands and directions.


73, Jim K9YC


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Re: [Elecraft] Antenna Quandary

[Fred Jensen]

They are known to radiate

73,

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

Richard wrote on 5/11/2022 1:58 PM:

Anybody out there super-well versed in the behavior of the half-wave dipole?

Cheers,

Richard Kunc
W4KBX
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Re: [Elecraft] Antenna Quandary

[David Gilbert]

You're a lot less likely to get an answer to that question than you 
would the answer to whatever question you actually want answered.


Dave   AB7E


On 5/11/2022 1:56 PM, Richard wrote:

Anybody out there super-well versed in the behavior of the half-wave dipole?

Cheers,

Richard Kunc
W4KBX
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Re: [Elecraft] Antenna Quandary

[Curt Nixon]

It's showing up on the reflector.  Kind of leading, no win question.  But
I'm a suckered. Been using 1/2 wave dipoles for 60 years. What is the
question?

On Wed, May 11, 2022, 5:06 PM Richard  wrote:

> I’m trying to send this to the reflector at large, but it keeps attaching
> John’s name. Sorry, John. This will be my third try.
>
> Anybody out there super-well versed in the behavior of the half-wave
> dipole?
>
> Cheers,
>
> Richard Kunc
> W4KBX
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Re: [Elecraft] Antenna and Propagation class notes addendum

[Tony Estep]

On Sat, Feb 13, 2021 at 11:11 AM kevinr  wrote:

> ...I found a few Bessel functions which still give me pause...

===
Yep.

73, Tony KT0NY
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Re: [Elecraft] Antenna Support Poles, Mil-Surplus SOLD

[James Bennett via Elecraft]

That was fast - the poles and bag are sold.

Jim Bennett
Folsom, CA


K7TXA (ex W6JHB as of 1/22/2021)

Being retired doesn't mean I'm not part of the work force - just that I'm not 
forced to work!



> On Jan 24, 2021, at 3:30 PM, James Bennett via Elecraft 
>  wrote:
> 
> In my continuing efforts to downsize before moving out of state, I’m trying 
> to sell 23 military surplus fiberglass antenna / tent support poles, in bag. 
> They are about 2-1/2” inches OD and slip together with a 3” or so overlap. 
> Each tube is approximately 44 “ long. I used these poles for almost 10 years 
> to support a 110 foot run of 600-ohm ladder line from one side of our house 
> to the other and up to the top of a 45’ mast. They are quite sturdy and are 
> in fairly good shape.
> 
> Total weight of the poles and bag is about 50-some pounds, so I’m not going 
> to ship them, unless you want to pay the Post Office some outrageous amount 
> of money. That said, if you live anywhere in the Sacramento, Folsom, 
> Roseville, Rancho Cordova, etc. area you can pick them up and they will run 
> you only $25.
> 
> Photos may be seen at:
> 
> https://imgsrv.sellersourcebook.com/users/121967/poles1.jpg 
> 
> 
> https://imgsrv.sellersourcebook.com/users/121967/poles2.jpg 
> 
> 
> Contact me off-list if you are interested.  
> 
> 
> Jim Bennett
> Folsom, CA
> 
> K7TXA (ex W6JHB as of 1/22/2021)
> 
> Being retired doesn't mean I'm not part of the work force - just that I'm not 
> forced to work!
> 
> 
> 
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Re: [Elecraft] Antenna tuners

[Fred Jensen]

More than just them.  Steve, K6OIK, who has presented at a number of 
past Pacificons speaks about the Myths of Conjugate Matching in a 
Pacificon presentation from 2011 at 
https://www.fars.k6ya.org/docs/Conjugate-Match-Myths.pdf It begins on 
page 20.  This is Dr. Stearns home turf, it can be a little technically 
dense in places.


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

On 7/18/2020 3:46 PM, hawley, charles j jr wrote:

Wasn't there a debate between Maxwell and Walter Bruene (designed the Collins 
30L1) on the conjugate match...I think Bruene disagreed with the popular notion 
of a conjugate match.

Jack BMW Motorcycles
Chuck KE9UW
c-haw...@illinois.edu




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Re: [Elecraft] Antenna tuners

[hawley, charles j jr]

Wasn't there a debate between Maxwell and Walter Bruene (designed the Collins 
30L1) on the conjugate match...I think Bruene disagreed with the popular notion 
of a conjugate match.

Jack BMW Motorcycles
Chuck KE9UW
c-haw...@illinois.edu

Sent from my iPad

> On Jul 18, 2020, at 3:01 PM, Gary Peterson  wrote:
> 
> You are in good company with Walter Maxwell, W2DU, now silent key.  Maxwell 
> was an engineer at RCA.  He designed the antennas on several earth orbiting 
> satellites and the antenna on the Lunar Rover.  He explained this quite 
> succinctly in his book Reflections (all three editions), by use of the 
> conjugate matching theorem.  As I recall, that chapter in his book (peer 
> reviewed by the RCA engineering department) was called My Antenna Tuner Tunes 
> My Antenna.
> 
> Gary, K0CX
> 
> But if the "tuner" is an LC network, like an adjustable L network, T network, 
> Pi network, or a linked-coupled network, then I strongly disagree.
> A tuner is a 2-port network. A transmission line is also a 2-port network. 
> Both networks obey reciprocity, meaning that what you do to one port of the 
> network will have a direct influence on the opposite end.
> That being said, if an antenna exhibits a complex impedance at our frequency 
> of interest, and that behavior can be corrected (brought to resonance) by the 
> application of a particular value of reactance at the antenna's feedpoint, 
> then that application of reactance can, for reasons of convenience, be made 
> at the "shack end" of the transmission line. As such, the "tuner" in the 
> shack is really "tuning" the antenna!
> John, KD2BD
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Re: [Elecraft] Antenna tuners

[Fred Jensen]

I very vaguely remember there was a different optimum length for the 
others, thanks!


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

On 7/18/2020 12:25 PM, W2xj wrote:

That only applies to class A stations with protected skywave. Otherwise, 
something near 225 degrees is best.

Sent from my iPhone


On Jul 18, 2020, at 11:33, Fred Jensen  wrote:

And the Texas Bug Catcher, Webster BandSpanner, SteppIR's, et al.  All 
represent changes to the antenna itself, which would also include changing the 
height [e.g. cranking the tower up and down] and possibly cutting down nearby 
trees or metal buildings [:=).  Any change to the antenna itself or its 
near-field environment will affect the feed point complex impedance.  This 
would include adding traps, inductors, and capacitors to the antenna.

When you're done flutzing with the antenna itself, you are stuck with whatever 
complex impedance you find at the feed point.  AM broadcast verticals are 
generally engineered for coverage near the edges of the market area, meeting 
non-interference FS requirements, and minimizing self-cancellation between the 
ground and sky wave.  Something in the vicinity of 195 degrees is generally 
optimal.  They are not usually resonant and there will be fixed matching 
network(s) at the base(s) ... AM broadcast stations aren't known to QSY much.

I'm not familiar with the TurboTuner however many mechanical antenna adjusters 
operated by driving the phase angle between voltage and current to zero, that 
is effectively bringing the antenna into resonance so the feedline sees a 
resistive load. It's up to you to design the antenna so that resistive load 
matches the characteristic impedance of the feedline OR put a matching network 
between the feedline and the antenna feedpoint OR tolerate the SWR on the line 
and put the matching network in the shack.  Pick one.



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Re: [Elecraft] Antenna tuners

[W2xj]

That only applies to class A stations with protected skywave. Otherwise, 
something near 225 degrees is best. 

Sent from my iPhone

> On Jul 18, 2020, at 11:33, Fred Jensen  wrote:
> 
> And the Texas Bug Catcher, Webster BandSpanner, SteppIR's, et al.  All 
> represent changes to the antenna itself, which would also include changing 
> the height [e.g. cranking the tower up and down] and possibly cutting down 
> nearby trees or metal buildings [:=).  Any change to the antenna itself or 
> its near-field environment will affect the feed point complex impedance.  
> This would include adding traps, inductors, and capacitors to the antenna.
> 
> When you're done flutzing with the antenna itself, you are stuck with 
> whatever complex impedance you find at the feed point.  AM broadcast 
> verticals are generally engineered for coverage near the edges of the market 
> area, meeting non-interference FS requirements, and minimizing 
> self-cancellation between the ground and sky wave.  Something in the vicinity 
> of 195 degrees is generally optimal.  They are not usually resonant and there 
> will be fixed matching network(s) at the base(s) ... AM broadcast stations 
> aren't known to QSY much.
> 
> I'm not familiar with the TurboTuner however many mechanical antenna 
> adjusters operated by driving the phase angle between voltage and current to 
> zero, that is effectively bringing the antenna into resonance so the feedline 
> sees a resistive load. It's up to you to design the antenna so that resistive 
> load matches the characteristic impedance of the feedline OR put a matching 
> network between the feedline and the antenna feedpoint OR tolerate the SWR on 
> the line and put the matching network in the shack.  Pick one.
> 
> 73,
> Fred ["Skip"] K6DGW
> Sparks NV DM09dn
> Washoe County
> 
>> On 7/17/2020 9:44 PM, Rick NK7I wrote:
>> Save one; the screwdriver antenna on my truck is tuned (coil adjusted) by 
>> the TurboTuner attached to my radio until a match is found.
>> 
>> And an argument could be made that a SteppIR controller performs a similar 
>> function.
>> 
>> The rest are matching circuits to compensate for the disparity of input to 
>> output.  
>> 
>> 73,
>> Rick NK7I
>> 
>> Email spiel Czech corruptions happen
>> 
 On Jul 17, 2020, at 7:00 PM, Fred Jensen  wrote:
>>> 
>>> No antenna has, at any time, anywhere in any of our lifetimes, been 
>>> "tuned" by an "antenna tuner."  So called antenna tuners are 2-port 
>>> impedance matching networks ... all of them ... and their

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Re: [Elecraft] Antenna tuners

[Fred Jensen]

And the Texas Bug Catcher, Webster BandSpanner, SteppIR's, et al.  All 
represent changes to the antenna itself, which would also include 
changing the height [e.g. cranking the tower up and down] and possibly 
cutting down nearby trees or metal buildings [:=).  Any change to the 
antenna itself or its near-field environment will affect the feed point 
complex impedance.  This would include adding traps, inductors, and 
capacitors to the antenna.


When you're done flutzing with the antenna itself, you are stuck with 
whatever complex impedance you find at the feed point.  AM broadcast 
verticals are generally engineered for coverage near the edges of the 
market area, meeting non-interference FS requirements, and minimizing 
self-cancellation between the ground and sky wave.  Something in the 
vicinity of 195 degrees is generally optimal.  They are not usually 
resonant and there will be fixed matching network(s) at the base(s) ... 
AM broadcast stations aren't known to QSY much.


I'm not familiar with the TurboTuner however many mechanical antenna 
adjusters operated by driving the phase angle between voltage and 
current to zero, that is effectively bringing the antenna into resonance 
so the feedline sees a resistive load. It's up to you to design the 
antenna so that resistive load matches the characteristic impedance of 
the feedline OR put a matching network between the feedline and the 
antenna feedpoint OR tolerate the SWR on the line and put the matching 
network in the shack.  Pick one.


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

On 7/17/2020 9:44 PM, Rick NK7I wrote:

Save one; the screwdriver antenna on my truck is tuned (coil adjusted) by the 
TurboTuner attached to my radio until a match is found.

And an argument could be made that a SteppIR controller performs a similar 
function.

The rest are matching circuits to compensate for the disparity of input to 
output.  

73,
Rick NK7I

Email spiel Czech corruptions happen


On Jul 17, 2020, at 7:00 PM, Fred Jensen  wrote:

No antenna has, at any time, anywhere in any of our lifetimes, been "tuned" by an "antenna 
tuner."  So called antenna tuners are 2-port impedance matching networks ... all of them ... and their 
job is to match the impedance on one port to another impedance on the second port, period.  Nothing gets 
"tuned."  They come in a variety of flavors ... a pair of push-pull 807's with a resonant tank and 
a link feed to the antenna on open wire line is one.  Everything that happens on the feed line [regardless of 
it's construction] is the sole result of the complex impedance at the antenna feed point and the 
characteristic impedance of the feedline.  No magic.

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


On 7/17/2020 5:14 PM, Ken Roberson via Elecraft wrote:
  Kurt,
We are not tuning the antenna , we are matching the antenna to the coax at the 
base of the antenna.
73 Ken K5DNL

 On Friday, July 17, 2020, 7:10:32 PM CDT, Kurt Pawlikowski 
 wrote:
 Ken: In some respects, a "matching device" at the base of the antenna is a 
tuner! {'-) It accomplishes the same function... {'-) k WB9FMC
On 7/17/2020 6:34 PM, Ken Roberson via Elecraft wrote:
 Antenna tuners

I never use an antenna tuner , on the MF and LF bands realmen use a scopematch 
at the

Output of the Power Amp and a matching device at the base ofthe vertical 
antenna – HI Hi.

73 Ken K5DNL


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Re: [Elecraft] Antenna tuners

[Rick NK7I]

Save one; the screwdriver antenna on my truck is tuned (coil adjusted) by the 
TurboTuner attached to my radio until a match is found. 

And an argument could be made that a SteppIR controller performs a similar 
function. 

The rest are matching circuits to compensate for the disparity of input to 
output.  

73,
Rick NK7I

Email spiel Czech corruptions happen

> On Jul 17, 2020, at 7:00 PM, Fred Jensen  wrote:
> 
> No antenna has, at any time, anywhere in any of our lifetimes, been "tuned" 
> by an "antenna tuner."  So called antenna tuners are 2-port impedance 
> matching networks ... all of them ... and their job is to match the impedance 
> on one port to another impedance on the second port, period.  Nothing gets 
> "tuned."  They come in a variety of flavors ... a pair of push-pull 807's 
> with a resonant tank and a link feed to the antenna on open wire line is one. 
>  Everything that happens on the feed line [regardless of it's construction] 
> is the sole result of the complex impedance at the antenna feed point and the 
> characteristic impedance of the feedline.  No magic.
> 
> 73,
> Fred ["Skip"] K6DGW
> "Captain Obvious"
> Sparks NV DM09dn
> Washoe County
> 
>> On 7/17/2020 5:14 PM, Ken Roberson via Elecraft wrote:
>>  Kurt,
>> We are not tuning the antenna , we are matching the antenna to the coax at 
>> the base of the antenna.
>> 73 Ken K5DNL
>> 
>> On Friday, July 17, 2020, 7:10:32 PM CDT, Kurt Pawlikowski 
>>  wrote:
>> Ken: In some respects, a "matching device" at the base of the antenna is 
>> a tuner! {'-) It accomplishes the same function... {'-) k WB9FMC
>>On 7/17/2020 6:34 PM, Ken Roberson via Elecraft wrote:
>> Antenna tuners
>> 
>> I never use an antenna tuner , on the MF and LF bands realmen use a 
>> scopematch at the
>> 
>> Output of the Power Amp and a matching device at the base ofthe vertical 
>> antenna – HI Hi.
>> 
>> 73 Ken K5DNL
>> 
> 
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Re: [Elecraft] Antenna tuners

[David Gilbert]

That's not in the least true, but those among us fixated on semantics 
continue to push that tired old myth.


You could, for example, have an antenna with a feedpoint impedance of 50 
- j40 ohms, and if you insert 40 ohms worth of inductance in series with 
the feedline at the feedpoint you will TUNE that antenna to resonance 
exactly the same as if you put an appropriate amount of reactance in the 
antenna itself or adjust its length ... all of which do exactly the same 
thing.  The antenna and it's feedline are inseparable as far as the 
overall network is concerned.  One is not independent of the other ... 
ever.


Furthermore, the adjustment (i.e., "tuning") can be done at the shack 
end of the feedline with EXACTLY the same effect except for the 
transmission line transformation by the feedline, and of course its 
associated loss, since whatever is done at the shack end is reflected 
back to the antenna end.


Yours is really a very tedious distinction that has no basis in actual 
physics or network theory.


73,
Dave   AB7E



On 7/17/2020 6:59 PM, Fred Jensen wrote:
No antenna has, at any time, anywhere in any of our lifetimes, been 
"tuned" by an "antenna tuner."  So called antenna tuners are 2-port 
impedance matching networks ... all of them ... and their job is to 
match the impedance on one port to another impedance on the second 
port, period.  Nothing gets "tuned."  They come in a variety of 
flavors ... a pair of push-pull 807's with a resonant tank and a link 
feed to the antenna on open wire line is one. Everything that happens 
on the feed line [regardless of it's construction] is the sole result 
of the complex impedance at the antenna feed point and the 
characteristic impedance of the feedline.  No magic.


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


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Re: [Elecraft] Antenna tuners

[John Magliacane via Elecraft]

 On Friday, July 17, 2020, 10:03:24 PM EDT, Fred Jensen  
wrote:

> No antenna has, at any time, anywhere in any of our lifetimes, been
> "tuned" by an "antenna tuner."

Unless the "tuner" is simply a broadband transformer, I might agree.

But if the "tuner" is an LC network, like an adjustable L network, T network, 
Pi network, or a linked-coupled network, then I strongly disagree.

A tuner is a 2-port network. A transmission line is also a 2-port network. Both 
networks obey reciprocity, meaning that what you do to one port of the network 
will have a direct influence on the opposite end.

That being said, if an antenna exhibits a complex impedance at our frequency of 
interest, and that behavior can be corrected (brought to resonance) by the 
application of a particular value of reactance at the antenna's feedpoint, then 
that application of reactance can, for reasons of convenience, be made at the 
"shack end" of the transmission line. As such, the "tuner" in the shack is 
really "tuning" the antenna!

There's no "magic" involved here -- just a simple understanding that things 
that are connected together actually behave like they're connected together. A 
transmission line doesn't isolate the shack from the antenna: It couples them 
together with the highest degree of efficiency we can muster/afford. Therefore, 
what happens at one end of a transmission line DIRECTLY affects the other, and 
vice versa.

And so, properly applying an adjustable LC impedance matching network in the 
shack CAN (and often does) modify the resonant frequency of an antenna.


73 de John, KD2BD
  
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Re: [Elecraft] Antenna tuners

[Fred Jensen]

No antenna has, at any time, anywhere in any of our lifetimes, been 
"tuned" by an "antenna tuner."  So called antenna tuners are 2-port 
impedance matching networks ... all of them ... and their job is to 
match the impedance on one port to another impedance on the second port, 
period.  Nothing gets "tuned."  They come in a variety of flavors ... a 
pair of push-pull 807's with a resonant tank and a link feed to the 
antenna on open wire line is one.  Everything that happens on the feed 
line [regardless of it's construction] is the sole result of the complex 
impedance at the antenna feed point and the characteristic impedance of 
the feedline.  No magic.


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

On 7/17/2020 5:14 PM, Ken Roberson via Elecraft wrote:

  Kurt,
We are not tuning the antenna , we are matching the antenna to the coax at the 
base of the antenna.
73 Ken K5DNL

 On Friday, July 17, 2020, 7:10:32 PM CDT, Kurt Pawlikowski 
 wrote:
  
   
Ken: In some respects, a "matching device" at the base of the antenna is a tuner! {'-) It accomplishes the same function... {'-) k WB9FMC
  
  On 7/17/2020 6:34 PM, Ken Roberson via Elecraft wrote:
   
  Antenna tuners


I never use an antenna tuner , on the MF and LF bands realmen use a scopematch 
at the

Output of the Power Amp and a matching device at the base ofthe vertical 
antenna – HI Hi.

73 Ken K5DNL



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Re: [Elecraft] Antenna tuners

[John Magliacane via Elecraft]

 On Friday, July 17, 2020, 7:10:32 PM CDT, Kurt Pawlikowski  
wrote: 
 
> Ken: In some respects, a "matching device" at the base of the antenna is a 
> tuner! {'-) It accomplishes the same function... {'-) k
> WB9FMC

On Friday, July 17, 2020, 08:21:54 PM EDT, Ken Roberson via Elecraft 
 wrote:

> Kurt,
> We are not tuning the antenna , we are matching the antenna to the coax at 
> the base of the antenna.
> 73 Ken K5DNL

Kurt's correct. A low-loss (non-resistive) matching network connected directly 
at the feedpoint of an antenna will modify its resonant frequency.

A matching network connected to the feedpoint of an antenna through 1 inch 
(25.4mm) of transmission line will also modify the resonant frequency of the 
antenna.

A matching network connected through 1 meter of transmission line will also 
modify the resonant frequency of the antenna.

A matching network connected through 10 meters of transmission line will also 
modify the resonant frequency of the antenna.

And so on, and so forth... all the way back to the shack! ;-)

Why? Because transmission lines obey reciprocity. As such they cannot (aside 
from the effects of losses) separate what's on their source end from what's on 
their load end. What you do to one end directly affects the other, and vice 
versa.

Show me a transmission line that disobeys this property, and I'll show you a 
line that is either opened or shorted.

So, yes, a non-resistive matching network in the shack will bring your antenna 
SYSTEM (antenna + transmission line) into resonance at your operating 
frequency. In the process, the resonant frequency of the antenna is modified, 
as well.


73 de John, KD2BD
  
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Re: [Elecraft] Antenna tuners

[Ken Roberson via Elecraft]

 Dave - RRR - 73 Ken K5DNL

On Friday, July 17, 2020, 7:24:10 PM CDT, Dave Cole  wrote:  
 
 Tuners...  Tuners...  We don't need no stinking tuners...  Real men use 
antennas that don't need stinking tuners...

Sorry I had too...

73, and thanks,
Dave (NK7Z)
https://www.nk7z.net
ARRL Volunteer Examiner
ARRL Technical Specialist
ARRL Asst. Director, NW Division, Technical Resources

On 7/17/20 4:34 PM, Ken Roberson via Elecraft wrote:
> 
> Antenna tuners
> 
> I never use an antenna tuner , on the MF and LF bands realmen use a 
> scopematch at the
> 
> Output of the Power Amp and a matching device at the base ofthe vertical 
> antenna – HI Hi.
> 
> 73 Ken K5DNL
> 
>  
> 
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Re: [Elecraft] Antenna tuners

[Dave Cole]

Tuners...  Tuners...  We don't need no stinking tuners...  Real men use 
antennas that don't need stinking tuners...


Sorry I had too...

73, and thanks,
Dave (NK7Z)
https://www.nk7z.net
ARRL Volunteer Examiner
ARRL Technical Specialist
ARRL Asst. Director, NW Division, Technical Resources

On 7/17/20 4:34 PM, Ken Roberson via Elecraft wrote:


Antenna tuners

I never use an antenna tuner , on the MF and LF bands realmen use a scopematch 
at the

Output of the Power Amp and a matching device at the base ofthe vertical 
antenna – HI Hi.

73 Ken K5DNL

  


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Re: [Elecraft] Antenna tuners

[Ken Roberson via Elecraft]

 Kurt,
We are not tuning the antenna , we are matching the antenna to the coax at the 
base of the antenna.
73 Ken K5DNL

On Friday, July 17, 2020, 7:10:32 PM CDT, Kurt Pawlikowski 
 wrote:  
 
  
Ken: In some respects, a "matching device" at the base of the antenna is a 
tuner! {'-) It accomplishes the same function... {'-) k WB9FMC
 
 On 7/17/2020 6:34 PM, Ken Roberson via Elecraft wrote:
  
 Antenna tuners

I never use an antenna tuner , on the MF and LF bands realmen use a scopematch 
at the

Output of the Power Amp and a matching device at the base ofthe vertical 
antenna – HI Hi.

73 Ken K5DNL

 

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Re: [Elecraft] Antenna tuners

[Kurt Pawlikowski]

Ken: In some respects, a "matching device" at the base of the antenna 
_/is/_ a tuner! {'-) It accomplishes the same function... {'-) k WB9FMC


On 7/17/2020 6:34 PM, Ken Roberson via Elecraft wrote:

Antenna tuners

I never use an antenna tuner , on the MF and LF bands realmen use a scopematch 
at the

Output of the Power Amp and a matching device at the base ofthe vertical 
antenna – HI Hi.

73 Ken K5DNL

  


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Re: [Elecraft] Antenna Routing

[Gareth M5KVK]

Thanks, Mike
It's a K3S, so it has the upgraded KSYN3As

Gareth, M5KVK

On 28/05/2020, 18:29, "Mike Harris"  wrote:

Did I read at some stage that you do not have the internal ATU? That 
being so you will not have selectable ANT 1 or ANT 2. That being the 
case you will only have AN1 1 (the main RX/TX antenna) or the Aux RF 
antenna available to you for the Sub RX. You can forget all the ANT 1 or 
ANT 2 stuff because you don't have an ANT 2 available.

With the SUB RX activated (tap SUB) and hold B SET which will then be 
displayed on the main display tapping the ANT button will toggle between 
Main and AUX. If you want the sub RX to listen on the same antenna as 
the main RX this should be set to MAIN.

For now forget RX ANT, just make sure the RX indicator is not showing on 
the main display (immediately under the third digit of the main 
frequency display).

This is the simple starting point. We are looking simply at Fig 1.

Is the K3 upgraded to the new synths? Probably not, however, old or new 
they both, and you need two, have to be the same, not mixed.

How are we doing?

Regards,

Mike VP8NO

On 28/05/2020 12:52, Gareth M5KVK wrote:
> Thanks for that, Mike. It seems to confirm my belief about what the 
CONFIG KRX3 option does.
> 
> However, I am not getting the behaviour expected from the description:
> 
> 
> Selecting The Main Receiver Antenna
> 
> Tap ANT to select ANT 1 or ANT 2. To select the receive antenna (RX ANT 
IN), tap RX ANT. The RX icon will turn on. You’ll still be able to tap ANT to 
select ANT 1 or ANT 2 for use with the transmitter.
> 
> Selecting The Subreceiver Antenna
> 
> Normally, the antenna icons (RX and ANT 1 - 2) show which antenna is in 
use by the main receiver. To see which antenna is selected for the subreceiver, 
hold BSET . BSET will appear on the VFO A display.
> While in BSET mode, the RX ANT switch is used to select the subreceiver’s 
auxiliary RF input (RX icon on). If the RX icon is off, the subreceiver is 
sharing the main receiver’s RF source. In either case, the ANT 1 - 2 icons will 
show which KAT3 antenna is available for use by the subreceiver. If sharing, it 
will be the same antenna in use by the main receiver. If not sharing, it will 
be the non-transmit antenna.
> 
> Tapping ANT while in BSET will switch antennas on the KAT3, affecting 
which antenna is in use by both the main and subreceivers, as well as the 
transmitter. When you exit BSET, look at the antenna icons to verify that any 
expected change in the settings for the main receiver has occurred.
> 
> 
> Selecting the main RX ANT works as expected. (I use a Mag Loop as an Rx 
Ant). However, I do not see the expected behaviour for the SUB.
> 
> If I hold BSET and tap RX ANT, the MAIN Rx ANT changes, not the SUB Rx 
ANT. I can't find a way to set the Rx icon when I am in BSET mode.
> 
> Gareth, M5KVK
> 
> On 28/05/2020, 16:11, "Mike Harris"  wrote:
> 
>  Hi Gareth,
> 
>  You might find the attached useful. It is a description of all the K3
>  antenna routing options, the complete Monty, basic to full house.
> 
>  Regards,
> 
>  Mike VP8NO
> 
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Re: [Elecraft] Antenna comment

[John Langdon]

John, NT5C (now SK) was a very smart guy, and well educated in both geology and 
electromagnetics.  He searched for his QTH via deed and terrain records, and 
the first screen was "must drain into 2 or more watersheds".  He found a killer 
spot with gently sloping foreground in almost all directions.  He went from an 
SWL to the Honor Roll in record time.

73 John N5CQ

-Original Message-
From: elecraft-boun...@mailman.qth.net  On 
Behalf Of Jim Danehy
Sent: Tuesday, March 17, 2020 4:47 AM
To: Elecraft Mailing List 
Subject: [Elecraft] Antenna comment

You can be a mile high (5,280’) on a plateau that goes for many miles. That 
still is FLAT LAND as far as a TAKE OFF ANGLE.
What counts is the IMMEDIATE SLOPE of the land underneath the antenna. The 
first 1000 + feet is critical. The FIRST BOUNCE to the IONOSPHERE is the 
criterion for a DX LOCATION. My current location IMMEDIATELY slopes from 800 
feet to 400 feet for a mile. That occurs near major tributaries. The River has 
taken millions of years to shove the ground away and cut a path for the water 
to flow. That creates hills

Back in the late 1970s I operated the CQ WW SSB Contest as a mobile station. 
One hundred watts and an 8 foot whip. I parked at 800 feet above Sea Level and 
looked directly down on the Ohio River 400 feet down. In 2 days during the 
daylight hours I worked 76 DXCC entities. Results in 1976 CQ Magazine I think 
it was. 

High up in the mountains is not sufficient  if you don’t have an IMMEDIATE DROP 
OFF that slopes downward. That is known as the take off angle.

A station in Barbados (8P6) asked me : “what you got in that car a Henry 2K” ?
Some things you don’t forget.

73
Jim W9VNE 

Sent from my iPhone
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delivered to woyb10...@outlook.com 
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Re: [Elecraft] Antenna or KAT500/KPA500 Problem

[Victor Rosenthal 4X6GP]

I did a lot of testing with a tuner followed by a high-quality DX 
Engineering balun in a system with high, reactive SWR. I did not push it 
far enough to destroy the balun, but I did note a gradual increase in 
SWR. And yes, the rate of increase sped up as it got hotter. So I 
suggest testing just long enough to see the process start!


In your data, the SWR decreases and then increases. I started with the 
tuner set to provide an SWR to the transmitter of 1:1 so it could only 
increase.


Incidentally, I found that the balun ran much cooler if the reactive 
component of the line's impedance was canceled out by a balanced pair of 
(in this case) capacitors.


73,
Victor, 4X6GP
Rehovot, Israel
Formerly K2VCO
CWops no. 5
http://www.qsl.net/k2vco/

On 07/08/2019 16:40, Andy Durbin wrote:

"It is possible that the ferrites are heating. If that is the case,
you could test it by transmitting a steady carrier for a minute while
watching the SWR. If it’s heating, there should be a gradual rise."

I have data for SWR runaway events that I believe were caused by
heating of the ferrite cores in a common mode choke.  The SWR change
for these events was not gradual.  It was closer to exponential.
Once runaway starts SWR reaches the point that it trips something in
just a few seconds.   The ferrite choke was in easy reach (outside
but only 5 feet above ground) and nearly burned my fingers.  Made me
think about oil immersion for cooling but have not tried that.
Instead I set a lower max power for that antenna.

KPA500 can be protected from these events by setting KAT500 key
interrupt threshold to a value lower than the SWR that trips the
KPA500.  My series of runaway events, and my attempts to protect
against them,  exposed a defect in the KAT500 utility so installation
of the latest version may be required.

Data for one event:

"SWR runaway and choke cores too hot to touch several minutes later. 
470 W 160 m FT8 with multiple transmissions before onset.


2019-03-27 21:11:15 TX_freq=1839500 2019-03-27 21:11:15 split offset
= -500 2019-03-27 21:11:31 New IF - IF1839500
0001612101;  << TX starts 2019-03-27 21:11:32 New VSWR  -
VSWR 1.34; 2019-03-27 21:11:32 split offset = -500 2019-03-27
21:11:32 New VSWR  - VSWR 1.33; 2019-03-27 21:11:32 New VSWR  - VSWR
1.31; 2019-03-27 21:11:32 New VSWR  - VSWR 1.29; 2019-03-27 21:11:33
New VSWR  - VSWR 1.27; 2019-03-27 21:11:33 New VSWR  - VSWR 1.25; 
2019-03-27 21:11:33 New VSWR  - VSWR 1.24; 2019-03-27 21:11:34 New

VSWR  - VSWR 1.22; <<<  SWR decreasing rapidly 2019-03-27
21:11:34 New VSWR  - VSWR 1.20; 2019-03-27 21:11:34 New VSWR  - VSWR
1.19; 2019-03-27 21:11:35 New VSWR  - VSWR 1.18; 2019-03-27 21:11:35
New VSWR  - VSWR 1.16; 2019-03-27 21:11:35 New VSWR  - VSWR 1.15; 
2019-03-27 21:11:35 New VSWR  - VSWR 1.13; 2019-03-27 21:11:36 New
VSWR  - VSWR 1.11; 2019-03-27 21:11:36 New VSWR  - VSWR 1.10; 
2019-03-27 21:11:36 New VSWR  - VSWR 1.09;  <<<  SWR
passes through zero 2019-03-27 21:11:37 New VSWR  - VSWR 1.10; 
2019-03-27 21:11:37 New VSWR  - VSWR 1.11; 2019-03-27 21:11:37 New
VSWR  - VSWR 1.13; 2019-03-27 21:11:38 New VSWR  - VSWR 1.14; 
2019-03-27 21:11:38 New VSWR  - VSWR 1.19;  <<<  SWR
increasing rapidly 2019-03-27 21:11:38 New VSWR  - VSWR 1.22; 
2019-03-27 21:11:38 New VSWR  - VSWR 1.25; 2019-03-27 21:11:38 New
VSWR  - VSWR 1.29; 2019-03-27 21:11:38 New VSWR  - VSWR 1.34; 
2019-03-27 21:11:38 New VSWR  - VSWR 1.39; 2019-03-27 21:11:39 New
VSWR  - VSWR 1.44; 2019-03-27 21:11:39 New VSWR  - VSWR 1.50; 
2019-03-27 21:11:39 New VSWR  - VSWR 1.58; 2019-03-27 21:11:40 New

VSWR  - VSWR 1.65; 2019-03-27 21:11:40 New FLT  - FLT4;
 KAT500 fault trip 2019-03-27 21:11:40 New AMPI  - AMPI1;
 Key line opened 2019-03-27 21:11:40 New VSWR  - VSWR 1.66; 
2019-03-27 21:11:40 New VSWR  - VSWR 1.67; 2019-03-27 21:11:40 New
VSWR  - VSWR 1.70; 2019-03-27 21:11:41 New VSWR  - VSWR 1.72; 
2019-03-27 21:11:42 New VSWR  - VSWR 1.70; 2019-03-27 21:11:42 New

VSWR  - VSWR 1.72; 2019-03-27 21:11:42 New VSWR  - VSWR 1.70;
<<< SWR peaks 2019-03-27 21:11:43 New VSWR  - VSWR 1.69; 2019-03-27
21:11:43 New VSWR  - VSWR 1.67; 2019-03-27 21:11:44 New VSWR  - VSWR
1.66; 2019-03-27 21:11:45 New IF - IF184
0001602001;  << TX ends"

(When interpreting the data be sure to note that only parameter
changes are recorded.  This means the events are not at equal time
intervals.  Later data recordings are tagged with 1 millisecond time
resolution which makes analysis a bit easier)

73, Andy, k3wyc 
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Re: [Elecraft] Antenna or KAT500/KPA500 Problem

[Vic Rosenthal]

It is possible that the ferrites are heating. If that is the case, you could 
test it by transmitting a steady carrier for a minute while watching the SWR. 
If it’s heating, there should be a gradual rise.
Twin lead will change characteristics significantly when it gets wet. So will 
ladder line, although not as much. So if this happens when it rains, that’s the 
issue.
There is also the possibility that there is a badly corroded connection inside 
the balun which opens when something expands due to heat. I once had this 
problem with what seemed to me to be a very well-constructed bead balun. The 
connection to the coax connector was the culprit. It was hard to find because 
it was intermittent.
If you replace the twinlead with ladder line, it will need to be slightly 
longer because the ladder line has a greater velocity factor than the twinlead. 
The Vf of twinlead is about 78% and of ladder line 91% so it will be longer by 
a factor of 1.17.

Victor 4X6GP 

> On 7 Aug 2019, at 5:00, Mike Lichtman via Elecraft  
> wrote:
> 
>Every so often at random after I have been on SSB for a while  ( 80m with 
> about 450w and a 1.1 to 1 SWR)  my tuner jumps to retune or the amp faults 
> and switches to standby. I am using a Van Gorden full size (102’) G5RV as 
> an inverted vee. The 31’ matching section is 300 ohm twin lead and, even 
> though it has been up for 10yrs, is still flexible. Van Gordon is now out of 
> business. The twin lead goes into a 3/4” pvc pipe and coax comes out the 
> other end.
> I am thinking that the 12” long pipe section has ferrite beads to cut common 
> mode currents. I don’t know what wattage the ferrites are rated for. 
>   Someone suggested that the ferrites might be heating up and causing my 
> problem since the problem occurs after being on the air a while and could be 
> thermal. 
>My questions are:
>I have some new 450 ohm ladder line. Should I replace the 300 
> ohm with it? I know that most G5RV’s on the market today use 450 ohm not 
> twinlead. If so what kind of line isolator is needed or what balun?  Should I 
>  just replace the ferrite beads — and if so with what no. and mix. Can I just 
> use an ugly balun (coiled coax). All thoughts are appreciated. The antenna 
> itself has worked fine for me on all bands (80 thru 10) and I have worked all 
> continents except Antarctica. Thank you in advance and 73 Mike KF6KXG
>
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Re: [Elecraft] Antenna or KAT500/KPA500 Problem

[Jim Brown]

On 8/6/2019 7:00 PM, Mike Lichtman via Elecraft wrote:

All thoughts are appreciated. The antenna itself has worked fine for me on all 
bands (80 thru 10)


You should buy yourself a copy of the ARRL Antenna Book and learn about 
how to build your own antennas.


That tube contains a lot of little ferrite beads that act as a common 
mode choke. This form of choke was developed many years ago by W2DU (now 
SK). If you haven't already fried it by running 500W you probably will 
eventually.


If your QTH allows more than one antenna, I strongly recommend the use 
of resonant fan dipoles fed with coax. They are very easy to build. If 
you do that, you can build your own common mode choke that is far 
superior to the one you bought with the antenna. 80 and 40 M makes a 
good combination for a fan, and the 40M element will work on 15M. If 
you're limited to 100 ft or so, consider one of the loaded 2-band 
dipoles built by Hypower Antenna Company (a ham in his basement), or buy 
the loading coils and build your own. I used one of his 80/40 loaded 
dipoles in Chicago. It also worked on 30 and 17. A 20M dipole is only 33 
ft long, so it's pretty easy to rig almost anywhere. I wouldn't worry 
about 15, 12, or 10M for the next 4-5 years, because they're nearly dead 
as we approach the bottom of the current solar cycle.


There are several "how to" tutorials on my website, k9yc.com/publish.htm 
, including one that describes how to build fan dipoles from inexpensive 
and readily available parts. My guidelines for chokes is at 
http://k9yc.com/2018Cookbook.pdf


73, Jim K9YC

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Re: [Elecraft] Antenna tuner range

[Don Wilhelm]

Steve,

The range of the T1 and the internal KX3 are about the same.

PS - why do folks insist on putting hyphens in the Elecraft model 
numbers - they do not belong, it is KX3 and not KX-3.

Look at the sales brochure or the webpage.

73,
Don W3FPR

On 3/6/2019 8:17 PM, Steve via Elecraft wrote:
I have an KX-3 with the built in tuner. How much wider range is the 
stand alone 20 QRP watt tuner? Thanks Steve kb1chu


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Re: [Elecraft] Antenna switching question

[Richard Ferch]

The KAT500 remembers its settings for each band/port combination. You can
connect several antennas to a given port through external switches, but if
two of those antennas are ever used on the same band, there is a danger
that the KAT500's settings that work with one of the antennas will be wrong
for the other antenna that you use on the same band/port combination,
requiring the KAT500 to retune every time you switch between those
antennas. To avoid this situation, you should try to make sure to the
extent possible that on any band where you use more than one antenna, those
antennas are connected to different ports on the KAT500.

Since you have three different antennas that are used on 20 and 15, you
should try to ensure that those three antennas are connected to separate
ports on the KAT500. That means that the LPDA, the vertical and the dipole
should all be on separate ports. In your case, once you have done that the
only antennas you have left are single-band antennas that you do not use on
any band that is shared with any other antenna, so you can put them on
whichever port you want.

If you are likely to be switching back and forth between two antennas
because their bands are often open at the same time, it might be best to
separate those antennas to minimize the number of times you need to operate
a manual antenna switch. That suggests putting the 160m inverted L on the
same port as the LPDA, to minimize the amount of switching back and forth
between 160 and 80/75 (where you use the other two antennas). The 6m
antenna can go anywhere; wherever you are least often likely to have to
switch back and forth, e.g. on the same port as the dipole.

73,
Rich VE3KI

WS1L wrote:

When I build the KAT500, what is the best use of the 3 ports available to
maximize it's tuning algorithm?  In other words, how can I maximize the
likelihood that a band change or QSY will result in a rapid tune due to
prior memorization, versus a somewhat longer full tune?
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Re: [Elecraft] Antenna switching question

[Joe Subich, W4TV]

Or, perhaps experienced users can tell me that the tuning works
quick enough that even if I try to confuse it the KAT500 will be
quick enough that it isn't an issue.

Since there is no overlap among the 160m inverted-L, LPDA (20-10)
and 6 meter Yagi, I would put them on the manual switch on one port.
That would leave the vertical and dipole on their own ports.

The KAT500 memorizes tuning by band and port so you should be able
to recall the memorized settings for frequency/band without any
confusion when selecting antennas/bands.

73,

   ... Joe, W4TV


On 2/22/2018 10:56 AM, Chuck Chandler wrote:

Currently I have five antennas connected to my K3S via a manual switch:

LPDA, 20 through 10
Vertical, CW on 80, low end of 40, 30, 20, 17, 15, 12 and 10.
Dipole, Phone on 75, phone on 40, 20, 15
Inverted-L on 160
Yagi on 6
Mostly the antennas are below 2:1, but they need some flattening on 160, 80
and 40 if I have to go beyond their sweet spots.

When I build the KAT500, what is the best use of the 3 ports available to
maximize it's tuning algorithm?  In other words, how can I maximize the
likelihood that a band change or QSY will result in a rapid tune due to
prior memorization, versus a somewhat longer full tune?

My thoughts were perhaps to put the 6 and 160 antennas each on their own
KAT500 port, then use the manual switch for the three that would cover HF.
Fine, except there could be a situation where the KAT500 had memorized a
tune for 7.100 that might be fine for the vertical but different for the
dipole.  The vertical is omni, so at times it would be a better choice than
the dipole.

Or, perhaps experienced users can tell me that the tuning works quick
enough that even if I try to confuse it the KAT500 will be quick enough
that it isn't an issue.

73 de Chuck, WS1L


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Re: [Elecraft] Antenna switching question

[Don Wilhelm]

Chuck,

Since you have a manual switch for your antennas --
Consider your operating habits.
Connect the 2 antennas you most frequently use to their own KAT500 port, 
then connect the others through your switch.


Since you have the vertical which covers all bands, and other bands that 
overlap band coverage, put the vertical on one KAT500 port.
Then put either the 160m or the 6 meter (whichever band you use most) on 
another port.  Connect the 3rd port to the antenna switch.
Select the vertical and the other antenna connected to the dedicated 
port with the ANT 1,2,3 selection on the KAT500, then with the antenna 
switch port selected, you switch between the other antennas.


Don't worry about the number of memories and antenna ports.  The KAT500 
will remember the tuning settings easily.  Just don't forget to operate 
the manual switch when you change to a particular band.


Another idea if it appeals to you and you have the subRX - use the 
vertical to connect to the AUX RX antenna on the K3 for the sub.  That 
allows you to use the vertical along with another horizontal antenna for 
diversity reception.


73,
Don W3FPR


On 2/22/2018 10:56 AM, Chuck Chandler wrote:

Currently I have five antennas connected to my K3S via a manual switch:

LPDA, 20 through 10
Vertical, CW on 80, low end of 40, 30, 20, 17, 15, 12 and 10.
Dipole, Phone on 75, phone on 40, 20, 15
Inverted-L on 160
Yagi on 6
Mostly the antennas are below 2:1, but they need some flattening on 160, 80
and 40 if I have to go beyond their sweet spots.

When I build the KAT500, what is the best use of the 3 ports available to
maximize it's tuning algorithm?  In other words, how can I maximize the
likelihood that a band change or QSY will result in a rapid tune due to
prior memorization, versus a somewhat longer full tune?

My thoughts were perhaps to put the 6 and 160 antennas each on their own
KAT500 port, then use the manual switch for the three that would cover HF.
Fine, except there could be a situation where the KAT500 had memorized a
tune for 7.100 that might be fine for the vertical but different for the
dipole.  The vertical is omni, so at times it would be a better choice than
the dipole.

Or, perhaps experienced users can tell me that the tuning works quick
enough that even if I try to confuse it the KAT500 will be quick enough
that it isn't an issue.

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Re: [Elecraft] Antenna tuning or matching unit

[Bob McGraw K4TAX]

I agree with Ron in that one must understand using an ATU at the transmitter 
does not change feedline loss. In fact it adds additional system loss due to 
loss incurred in the tuner.  If the transmitter can not deliver rated power 
into the load that is a different issue to resolve.  The ATU may accomplish 
this, but with added system loss. 

Bob, K4TAX


Sent from my iPhone

> On Feb 20, 2018, at 9:35 PM, Ron D'Eau Claire  wrote:
> 
> Alan your explanation opens the door to erroneous conclusions. Frequently a
> feed line does NOT have a low SWR by design. It is still a feed line in that
> it carries RF from the transmitter site to the radiator with a minimum of
> radiation from itself. A classic example is the Zepp antenna: a 1/2 wave
> long radiator fed at one end with a 1/4 wavelength long open wire feed line.
> The SWR on the feed line is intentionally very high because its function is
> to translate the very high impedance at the end of the radiator to a low
> impedance easily handled by the transmitter, nowadays generally using a
> matching network commonly called a "tuning unit" since modern transmitters
> are designed for a 50 ohm non-reactive load. 
> 
> Another example is a wire radiator fed at the center with open wire feed
> line for operation on a variety of bands. Again the SWR in the feed line
> will be very high, depending upon the length of the radiator, the length of
> the feed line and the frequency of operation. But, using a feed line with an
> impedance of 450 to 600 ohms, the SWR in a real-world H.F. installation
> where the radiator is at least 1/2 wavelength long at the lowest frequency
> of operation, the SWR on the open wire feed line will not exceed about 20:1
> so the losses will be very low. The real advantage to this setup is that the
> matching network can be in the shack and within easy reach of the operator
> instead of being mounted remotely at the center of the radiator. 
> 
> I present the use of 50 ohm coaxial line without a matching network as a
> "special case" where it possible to design a radiator or system of radiators
> that presents an impedance at its feed point that is a close enough match to
> 50 ohms without the network. However, using a low-impedance like such as the
> common coax means we must pay special attention to the SWR on the feed line
> to avoid excessive losses. For example, with 50 ohm coax in an HF
> installation, it is easy to realize an SWR of greater than 100:1 and very
> high losses. In such a case a matching network at the transmitter will not
> reduce the feed line losses.   
> 
> 73, Ron AC7AC
> 
> 
>> On 2/20/2018 8:16 PM, Alan B via Elecraft wrote:
>> This all depends on what is meant by antenna tuning.
>> When teaching newbies the wrong phrase can cause problems that are not
> seen till later.
>> Antennas are tuned with wire cutters or a hacksaw so the feed impedance is
> the desired value, ideally 50 ohm resistive or at least a match for the
> feeder concerned.
>> Of course that is not always practical so an antenna matching unit brings
> the antenna or antenna plus feeder input impedance to the value wanted by
> the transmitter.
>> Too often I have seen students believe the ATU alters the current and
> voltage distribution on the antenna so it looks exactly like the
> distribution on a dipole of the correct length for the frequency concerned.
>> Granted the currents and voltages might change as the ATU is adjusted but
> that does not make the antenna radiate more efficiently. The reflection at
> the feeder/antenna junction is unchanged.
>> In training we use the term antenna matching unit, AMU, to avoid best we
> can the students starting off with the wrong impression.
>> Amongst ourselves we can get away with slack terminology, we all know what
> is meant; in front of trainees it is a different story.
> 
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> 


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Re: [Elecraft] Antenna tuning or matching unit

[Bill Johnson]

Then there are those of us who use high ratio end fed half waves for specific 
frequencies with great luck.  I do this on 160 for 1.900 coverage.  This allows 
me to deviate marginally from that frequency with a matching unit.  Works great 
near 3.8 as well.  Now to get it further into the trees. Winter has hindered my 
latest experimental antenna.  NVIS is better than nothing :-).

73,
Bill
K9YEQ

-Original Message-
From: elecraft-boun...@mailman.qth.net <elecraft-boun...@mailman.qth.net> On 
Behalf Of Ron D'Eau Claire
Sent: Tuesday, February 20, 2018 9:36 PM
To: elecraft@mailman.qth.net
Subject: Re: [Elecraft] Antenna tuning or matching unit

Alan your explanation opens the door to erroneous conclusions. Frequently a 
feed line does NOT have a low SWR by design. It is still a feed line in that it 
carries RF from the transmitter site to the radiator with a minimum of 
radiation from itself. A classic example is the Zepp antenna: a 1/2 wave long 
radiator fed at one end with a 1/4 wavelength long open wire feed line.
The SWR on the feed line is intentionally very high because its function is to 
translate the very high impedance at the end of the radiator to a low impedance 
easily handled by the transmitter, nowadays generally using a matching network 
commonly called a "tuning unit" since modern transmitters are designed for a 50 
ohm non-reactive load. 

Another example is a wire radiator fed at the center with open wire feed line 
for operation on a variety of bands. Again the SWR in the feed line will be 
very high, depending upon the length of the radiator, the length of the feed 
line and the frequency of operation. But, using a feed line with an impedance 
of 450 to 600 ohms, the SWR in a real-world H.F. installation where the 
radiator is at least 1/2 wavelength long at the lowest frequency of operation, 
the SWR on the open wire feed line will not exceed about 20:1 so the losses 
will be very low. The real advantage to this setup is that the matching network 
can be in the shack and within easy reach of the operator instead of being 
mounted remotely at the center of the radiator. 

I present the use of 50 ohm coaxial line without a matching network as a 
"special case" where it possible to design a radiator or system of radiators 
that presents an impedance at its feed point that is a close enough match to
50 ohms without the network. However, using a low-impedance like such as the 
common coax means we must pay special attention to the SWR on the feed line to 
avoid excessive losses. For example, with 50 ohm coax in an HF installation, it 
is easy to realize an SWR of greater than 100:1 and very high losses. In such a 
case a matching network at the transmitter will not
reduce the feed line losses.   

73, Ron AC7AC


On 2/20/2018 8:16 PM, Alan B via Elecraft wrote:
> This all depends on what is meant by antenna tuning.
> When teaching newbies the wrong phrase can cause problems that are not
seen till later.
> Antennas are tuned with wire cutters or a hacksaw so the feed 
> impedance is
the desired value, ideally 50 ohm resistive or at least a match for the feeder 
concerned.
> Of course that is not always practical so an antenna matching unit 
> brings
the antenna or antenna plus feeder input impedance to the value wanted by the 
transmitter.
> Too often I have seen students believe the ATU alters the current and
voltage distribution on the antenna so it looks exactly like the distribution 
on a dipole of the correct length for the frequency concerned.
> Granted the currents and voltages might change as the ATU is adjusted 
> but
that does not make the antenna radiate more efficiently. The reflection at the 
feeder/antenna junction is unchanged.
> In training we use the term antenna matching unit, AMU, to avoid best 
> we
can the students starting off with the wrong impression.
> Amongst ourselves we can get away with slack terminology, we all know 
> what
is meant; in front of trainees it is a different story.

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Re: [Elecraft] Antenna tuning or matching unit

[Bill Johnson]

Don, thank you for the reference.  I know I read this back when you wrote it.  
I have saved as a reference for other operators, who seem to need a bit more 
understanding.

73,
Bill
K9YEQ

-Original Message-
From: elecraft-boun...@mailman.qth.net <elecraft-boun...@mailman.qth.net> On 
Behalf Of Don Wilhelm
Sent: Tuesday, February 20, 2018 8:10 PM
To: elecraft@mailman.qth.net
Subject: Re: [Elecraft] Antenna tuning or matching unit

On this subject, it may be of interest to point to the article on my website 
www.w3fpr.com "Antennas, Transmission Lines and Tuners".  This article first 
appeared in QRP Quarterly in July 2001.

I am pleased that DXzone has also recognized that article and has included it 
in its Antennas/Theory category - see 
https://www.dxzone.com/dx19232/antennas-and-transmission-lines-myths.html

There is not much math in the article, but you may find the concepts valuable.  
The sections on "SWR as a friend" and "Antenna Tuners" is particularly relevant 
to the current topic.

73,
Don W3FPR

On 2/20/2018 8:16 PM, Alan B via Elecraft wrote:
> This all depends on what is meant by antenna tuning.
> When teaching newbies the wrong phrase can cause problems that are not seen 
> till later.
> Antennas are tuned with wire cutters or a hacksaw so the feed impedance is 
> the desired value, ideally 50 ohm resistive or at least a match for the 
> feeder concerned.
> Of course that is not always practical so an antenna matching unit brings the 
> antenna or antenna plus feeder input impedance to the value wanted by the 
> transmitter.
> Too often I have seen students believe the ATU alters the current and voltage 
> distribution on the antenna so it looks exactly like the distribution on a 
> dipole of the correct length for the frequency concerned.
> Granted the currents and voltages might change as the ATU is adjusted but 
> that does not make the antenna radiate more efficiently. The reflection at 
> the feeder/antenna junction is unchanged.
> In training we use the term antenna matching unit, AMU, to avoid best we can 
> the students starting off with the wrong impression.
> Amongst ourselves we can get away with slack terminology, we all know what is 
> meant; in front of trainees it is a different story.
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Re: [Elecraft] Antenna tuning or matching unit

[Ron D'Eau Claire]

Alan your explanation opens the door to erroneous conclusions. Frequently a
feed line does NOT have a low SWR by design. It is still a feed line in that
it carries RF from the transmitter site to the radiator with a minimum of
radiation from itself. A classic example is the Zepp antenna: a 1/2 wave
long radiator fed at one end with a 1/4 wavelength long open wire feed line.
The SWR on the feed line is intentionally very high because its function is
to translate the very high impedance at the end of the radiator to a low
impedance easily handled by the transmitter, nowadays generally using a
matching network commonly called a "tuning unit" since modern transmitters
are designed for a 50 ohm non-reactive load. 

Another example is a wire radiator fed at the center with open wire feed
line for operation on a variety of bands. Again the SWR in the feed line
will be very high, depending upon the length of the radiator, the length of
the feed line and the frequency of operation. But, using a feed line with an
impedance of 450 to 600 ohms, the SWR in a real-world H.F. installation
where the radiator is at least 1/2 wavelength long at the lowest frequency
of operation, the SWR on the open wire feed line will not exceed about 20:1
so the losses will be very low. The real advantage to this setup is that the
matching network can be in the shack and within easy reach of the operator
instead of being mounted remotely at the center of the radiator. 

I present the use of 50 ohm coaxial line without a matching network as a
"special case" where it possible to design a radiator or system of radiators
that presents an impedance at its feed point that is a close enough match to
50 ohms without the network. However, using a low-impedance like such as the
common coax means we must pay special attention to the SWR on the feed line
to avoid excessive losses. For example, with 50 ohm coax in an HF
installation, it is easy to realize an SWR of greater than 100:1 and very
high losses. In such a case a matching network at the transmitter will not
reduce the feed line losses.   

73, Ron AC7AC


On 2/20/2018 8:16 PM, Alan B via Elecraft wrote:
> This all depends on what is meant by antenna tuning.
> When teaching newbies the wrong phrase can cause problems that are not
seen till later.
> Antennas are tuned with wire cutters or a hacksaw so the feed impedance is
the desired value, ideally 50 ohm resistive or at least a match for the
feeder concerned.
> Of course that is not always practical so an antenna matching unit brings
the antenna or antenna plus feeder input impedance to the value wanted by
the transmitter.
> Too often I have seen students believe the ATU alters the current and
voltage distribution on the antenna so it looks exactly like the
distribution on a dipole of the correct length for the frequency concerned.
> Granted the currents and voltages might change as the ATU is adjusted but
that does not make the antenna radiate more efficiently. The reflection at
the feeder/antenna junction is unchanged.
> In training we use the term antenna matching unit, AMU, to avoid best we
can the students starting off with the wrong impression.
> Amongst ourselves we can get away with slack terminology, we all know what
is meant; in front of trainees it is a different story.

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Re: [Elecraft] Antenna tuning or matching unit

[Don Wilhelm]

On this subject, it may be of interest to point to the article on my 
website www.w3fpr.com "Antennas, Transmission Lines and Tuners".  This 
article first appeared in QRP Quarterly in July 2001.


I am pleased that DXzone has also recognized that article and has 
included it in its Antennas/Theory category - see 
https://www.dxzone.com/dx19232/antennas-and-transmission-lines-myths.html


There is not much math in the article, but you may find the concepts 
valuable.  The sections on "SWR as a friend" and "Antenna Tuners" is 
particularly relevant to the current topic.


73,
Don W3FPR

On 2/20/2018 8:16 PM, Alan B via Elecraft wrote:

This all depends on what is meant by antenna tuning.
When teaching newbies the wrong phrase can cause problems that are not seen 
till later.
Antennas are tuned with wire cutters or a hacksaw so the feed impedance is the 
desired value, ideally 50 ohm resistive or at least a match for the feeder 
concerned.
Of course that is not always practical so an antenna matching unit brings the 
antenna or antenna plus feeder input impedance to the value wanted by the 
transmitter.
Too often I have seen students believe the ATU alters the current and voltage 
distribution on the antenna so it looks exactly like the distribution on a 
dipole of the correct length for the frequency concerned.
Granted the currents and voltages might change as the ATU is adjusted but that 
does not make the antenna radiate more efficiently. The reflection at the 
feeder/antenna junction is unchanged.
In training we use the term antenna matching unit, AMU, to avoid best we can 
the students starting off with the wrong impression.
Amongst ourselves we can get away with slack terminology, we all know what is 
meant; in front of trainees it is a different story.

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Re: [Elecraft] Antenna Analyzer (FA-VA4)

[Jim Brown]

Simple. Connect the analyzer output to one antenna, the input to the 
other.  Set the sweep range for that where you want to look at antenna 
coupling (usually one band for which the antennas are used). Make a 
sweep and tell the analyzer software to display S21 in dB.  S21 is the 
gain of a device or network.


73, Jim

On 12/3/2017 1:16 PM, Dick Green wrote:

Jim wrote:


Note also that this is a vector NETWORK analyzer. A NETWORK analyzer has input 
and output ports, so that in addition to impedance and TDR, it can also measure 
the response of any system. You can, for example, measure the effectiveness of 
filters, and the coupling between adjacent antennas.

Jim, for those of us who haven’t used a network analyzer, how do you use one to 
measure coupling between antennas?

73, Dick WC1M




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Re: [Elecraft] Antenna Analyzer (FA-VA4)

[Wes Stewart]

In this case think of the network analyzer as a transmitter with a receiver 
tuned to the same frequency.  Before testing you connect the two together and 
normalize the receiver response to unity at each test frequency. Now connect the 
transmitter port to one antenna and the receive port to the other antenna.  The 
response will be some fraction of unity, which can be presented as % 
transmitted, or more often in dB.


Wes  N7WS



On 12/3/2017 2:16 PM, Dick Green wrote:

Jim wrote:


Note also that this is a vector NETWORK analyzer. A NETWORK analyzer has input 
and output ports, so that in addition to impedance and TDR, it can also measure 
the response of any system. You can, for example, measure the effectiveness of 
filters, and the coupling between adjacent antennas.

Jim, for those of us who haven’t used a network analyzer, how do you use one to 
measure coupling between antennas?

73, Dick WC1M



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Re: [Elecraft] Antenna Analyzer (FA-VA4)

[ab2tc]

Hi,

That ought to be fairly straightforward. Connect one antenna to the the
output port of the analyzer and the other antenna to the input port. Then
set the sweep for the frequency range you want to test.

AB2TC - Knut


wc1m wrote
> Jim wrote:
> 
>> Note also that this is a vector NETWORK analyzer. A NETWORK analyzer has
>> input and output ports, so that in addition to impedance and TDR, it can
>> also measure the response of any system. You can, for example, measure
>> the effectiveness of filters, and the coupling between adjacent antennas.
> 
> Jim, for those of us who haven’t used a network analyzer, how do you use
> one to measure coupling between antennas?
> 
> 73, Dick WC1M
> 
> 
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Re: [Elecraft] Antenna Analyzer (FA-VA4)

[Dick Green]

Jim wrote:

> Note also that this is a vector NETWORK analyzer. A NETWORK analyzer has 
> input and output ports, so that in addition to impedance and TDR, it can also 
> measure the response of any system. You can, for example, measure the 
> effectiveness of filters, and the coupling between adjacent antennas.

Jim, for those of us who haven’t used a network analyzer, how do you use one to 
measure coupling between antennas?

73, Dick WC1M


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Re: [Elecraft] Antenna Analyzer

[John Perlick]

I have the SARK and have used it around the world.  It works great, is 
accurate, tiny, self contained and easy to use.  Only downside is price but 
mine has easily paid for itself (by reducing the number of times I had to climb 
my tower!). 

John Perlick
Aria Corporation
www.ariacorp.com

> On Dec 1, 2017, at 11:37 AM, "elecraft-requ...@mailman.qth.net" 
>  wrote:
> 
> Send Elecraft mailing list submissions to
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> 
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> When replying, please edit your Subject line so it is more specific
> than "Re: Contents of Elecraft digest..."
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> 
> Today's Topics:
> 
>   1.  Antenna Analyzer (John Harper)
>   2. Re: Antenna Analyzer (Dave Cole (NK7Z))
>   3. FR - KX2 max output now 12 watts (experimental) (John Oppenheimer)
>   4. Re: Antenna Analyzer (John Oppenheimer)
>   5. Re: Antenna Analyzer (Michael Walker)
>   6. Re: Antenna Analyzer (Jim Sheldon)
>   7. Re: Antenna Analyzer (Bob N3MNT)
>   8. Eleraft list (Paul (Tex) Herson)
>   9. For sale (Sid Leben)
>  10. Re: Antenna Analyzer (Dave Cole (NK7Z))
>  11. Re: Antenna Analyzer (Mike Cox)
>  12. Re: Antenna Analyzer (FA-VA4) (Peter Eijlander (PA0PJE))
>  13. Re: Antenna Analyzers (Mike Lichtman)
>  14. OT - Want to buy SideKar (Paul (Tex) Herson)
>  15. Antenna Analyzer (Dick Dickinson)
>  16. Re: Eleraft list (Charlie T)
>  17. Happiness is a new Elecraft Purchase (Mark Tosiello)
>  18. Re: Antenna Analyzer (Igor Sokolov)
>  19. Re: K3 PRE function question (Edward R Cole)
>  20. Re: K3 PRE function question (GRANT YOUNGMAN)
>  21. Re: Antenna Analyzer (FA-VA4) (Ignacy)
>  22. Re: Antenna Analyzer (FA-VA4) (Mark Goldberg)
>  23. Re: Antenna Analyzer (Doug Person)
>  24. Re: Antenna Analyzer (George Thornton)
>  25. K1 price? (Ken Alexander)
>  26. Re: Antenna Analyzer (Ronnie Hull)
>  27. Re: Antenna Analyzer (Michael Walker)
> 
> 
> --
> 
> Message: 1
> Date: Fri, 1 Dec 2017 06:57:08 -0600
> From: John Harper 
> To: Elecraft list 
> Subject: [Elecraft]  Antenna Analyzer
> Message-ID:
>

Re: [Elecraft] Antenna Analyzer

[Don Wilhelm]

Bob and all,

The "classic" formula for a wire half wave dipole (known to most hams) 
is 468/F (length in feet and frequency in MHz), and your "492 x K" 
factor is correct.  Sorry for those who use metric, you will have to 
convert)


However, that may not lead to a resonant antenna due to a number of 
factors - height above ground, proximity to other objects, diameter to 
length ratio of the wire among the most obvious factors.


In his years on this planet, L.B. Cebik long preached that "cutting 
formulas" such as 468/F were only an approximation.


Armed with an antenna analyzer and a calculator plus measuring tape, you 
can cut an antenna to be 'resonate' at the shack end of the antenna 
feedline in two tries.  The following technique appeared in QST 
Technical Correspondence for May 2017 (yes, it was my contribution).


The steps are as follows:
- Cut the antenna according to the 468/F formula and add 10%.  Write 
down the length.
- Put it into its final position and with the antenna analyzer, measure 
its resonance point (take your pick of whether that is point of lowest 
SWR or the point where the reactance goes to zero).
- Multiply the length of the antenna by the frequency you picked to call 
the resonant point.  That will yield a number to replace the "468" in 
the cutting formula.
- Use the resulting number and divide by the frequency where you want 
resonance to be.  That is the new length of the antenna.

- Cut the antenna to the new length and put it up and operate.

This works well for HF.  VHF may have other factors involved, so you may 
have to check the results again after the initial adjustment, but the 
principle remains the same.
This method takes into account the antenna surroundings and shortens the 
"cut and try" process considerably.


73
Don W3FPR


On 12/1/2017 3:22 PM, Bob McGraw K4TAX wrote:
Agreed.   I've always said hams cut an antenna a bit long and then trim 
it to get the lowest SWR at the desired frequency. This does not 
necessarily make for a resonant antenna.    My 75M antenna is resonant 
at 3.8 MHz as determined using a Grid Dip Oscillator,  but the impedance 
is about 35 ohms giving a SWR of about 1.4:1 .  At 3.9 MHz the SWR is 
1:1.  The length is actually 123 ft.  But the SWR 1:1 point indicates 
the antenna is 119.8 ft in length.


The resonant electrical length of a 1/2 wave dipole antenna is defined 
as Length being = (492 x K) / Frequency [MHz.]    This does not assure 
it will have a 1:1 SWR at the design frequency, but only that it will be 
resonant at that frequency.   {K = ratio of 1/2 wavelength to conductor 
diameter.  Typically for wire HF antennas a value of 0.95 is used.}



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Re: [Elecraft] Antenna Analyzer

[Bob McGraw K4TAX]

Agreed.   I've always said hams cut an antenna a bit long and then trim 
it to get the lowest SWR at the desired frequency. This does not 
necessarily make for a resonant antenna.    My 75M antenna is resonant 
at 3.8 MHz as determined using a Grid Dip Oscillator,  but the impedance 
is about 35 ohms giving a SWR of about 1.4:1 .  At 3.9 MHz the SWR is 
1:1.  The length is actually 123 ft.  But the SWR 1:1 point indicates 
the antenna is 119.8 ft in length.


The resonant electrical length of a 1/2 wave dipole antenna is defined 
as Length being = (492 x K) / Frequency [MHz.]    This does not assure 
it will have a 1:1 SWR at the design frequency, but only that it will be 
resonant at that frequency.   {K = ratio of 1/2 wavelength to conductor 
diameter.  Typically for wire HF antennas a value of 0.95 is used.}


Just remember, the radiation resistance of the antenna will vary 
according to height above ground.  Thus a 1/2 wave dipole at resonance 
will have its center feed impedance vary from some 20 ohms at 1/8 
wavelength above ground to over 90 ohms at 3/8 wavelength above ground.  
And at 1/2 wavelength above ground the impedance is near 70 ohms.  Of 
course ground conductivity will affect the actual results.


73

Bob, K4TAX


On 12/1/2017 1:54 PM, John Harper wrote:

Elecraft rigs, including the KX2, have an indicator for SWR that the rig
sees. Resonance can be clearly seen by moving up and down the band to
find it.

Not necessarily. Resonance and point of lowest SWR do not always coincide.

John AE5X
https://ae5x.blogspot.com
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Re: [Elecraft] Antenna Analyzer

[Bob McGraw K4TAX]

I find that Jim's thoughts and findings are similar to mine. SWR is 
really not a good indication of how well an antenna works. One of my 
coax lines has a 1:1 SWR from 160M through 6M.  It doesn't receive well 
nor transmit well.  It' has a dummy load on the distant end.


Along the same line, I have a home brew variable L network consisting of 
a tapped inductor, about 24 taps, and a 500 pf variable capacitor.  I 
find it will match about anything that is hung on one end.  If it 
doesn't match, simply turn it around and most likely a suitable match 
will be found.  In all cases, my random wire is not a resonant antenna 
but a length of wire tossed over a tree limb.   With this, the SWR 
indication on the radio is all that's needed.


73

Bob, K4TAX



On 12/1/2017 1:09 PM, Jim Brown wrote:

On 12/1/2017 4:49 AM, w5...@comcast.net wrote:
But it struck me that it might be nice to add a small antenna 
analyzer to my kit.


Why must every perceived problem be resolved by buying something? All 
Elecraft rigs, including the KX2, have an indicator for SWR that the 
rig sees. Resonance can be clearly seen by moving up and down the band 
to find it.


SWR is NOT an indicator of how well an antenna works, and antennas 
don't necessarily have to be resonant to work well! That depends on 
how we use the fundamentals of how antennas work. Especially when 
using improvised wire antennas with little or no feedline, the only 
thing that matters beyond the fundamental properties of the antenna is 
whether the rig can match it.


I'd be far more likely to drag along more "stuff" with which to rig 
improvised antennas in whatever surroundings I find myself, and to 
study the ARRL Handbook and Antenna Book to understand those 
fundamentals.


73, Jim K9YC



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Re: [Elecraft] Antenna Analyzer (FA-VA4)

[Jim Brown]

On 12/1/2017 10:30 AM, Wes Stewart wrote:

What calibrations are you doing that take an hour?

You can do a master cal with lots of points in 5 minutes.


Yes.  AND, more important, calibrations can be saved for standard 
measurement setups, so when you're always using a previous setup, 
there's no need to recalibrate -- you simply load the previous calibration.


I use mine in the field all the time using a Win 10 touch screen 
tablet.  The software is phenomenal.  I've been doing network analysis 
since the days when the calibration curve was a grease pencil line on 
a CRT.  I (my employer) bought one of the first HP8510s sold to a 
non-governmental agency.  It cost IIRC north of $200K, was in a 4-foot 
rack cabinet and probably weighed 500 pounds.  With an admittedly 
reduced frequency range, the VNWA3 is for all practical purposes the 
equal of the '8510 and I can hold it in the palm of my hand!


Like Wes, I've been doing swept complex (magnitude and phase) 
measurements since 1982, first in the audio range, later at RF.  I 
bought the VNWA3e about 4 years ago, and have found it to be the 
excellent that Wes describes.  It has an excellent TDR function. Another 
important advantage of this unit over others is that it is self-powered 
from the USB port, so no external power is required.


TDR can be VERY useful when troubleshooting an antenna or feedline 
problem, and the higher the analyzer can sweep, the more fine detail it 
can show. The VNWA can sweep to 1.3 GHz.  Few analyzers the do TDR can 
sweep nearly this high. A wideband TDR sweep can find all the splices 
and many defects in a feedline.


Another use of TDR is that it allows us to measure an antenna at the 
shack end of a feedline, find the electrical length of the feedline with 
the TDR feature, and then using Smith Chart software (free), subtract 
out the feedline to see the Z and SWR at the feedpoint.


Note also that this is a vector NETWORK analyzer. A NETWORK analyzer has 
input and output ports, so that in addition to impedance and TDR, it can 
also measure the response of any system. You can, for example, measure 
the effectiveness of filters, and the coupling between adjacent 
antennas. These plots of bandpass filter response were done with the 
VNWA 3e. Note that you can display several views of the same 
measurement. These display SWR, attenuation, and reflection loss, and 
the markers show values within the passband and on other ham bands.


http://audiosystemsgroup.com/BandpassFilterData.htm

These data were used to generate this report that ran in National 
Contest Journal in 2014.


http://k9yc.com/BandpassFilterSurvey.pdf

With a good external frequency standard (I use a Bodnar GPSDO) it 
makes an excellent frequency counter and works as a limited function 
spectrum analyzer.


Yes, and quite versatile in that mode. Inexpensive SDRs also provide 
limited spectrum analyzer functions, and some of them are quite good IF 
the user is careful to prevent overload and knows how to avoid false 
responses from aliasing.


One other thing.  On my 160-meter inverted-L antenna I receive a 
couple of AM broadcast stations at -3dBm.  If I limit the lower sweep 
frequency to 1.7 MHz the VNWA3 is unaffected.  I suspect some of these 
other boxes are not so resilient. 


This can be very important -- many analyzers get blown away by AM 
broadcast stations.


Here are links to the mfr, SDRKits. The VNWA is NOT a kit, it is built 
and fully tested. You want the model 3E or 3EC with calibration kit and 
cables.


https://www.sdr-kits.net/index.php?route=web/pages_id=29_29

https://www.sdr-kits.net/index.php?route=web/pages_id=68_68

73, Jim K9YC

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Re: [Elecraft] Antenna Analyzer

[GRANT YOUNGMAN]

Hi, Ronnie …

There are a bezillion to choose from — big, small, graphical, TDR, need a 
computer or pad,  etc, as others have pointed out.

Another one you might consider is the iP30z (or iP60z) retailed through 
Buddipole.  They’re a bit pricey compared to some options, but they have the 
advantage of being small enough to squeeze into virtually any bag or a shirt 
pocket, lightweight (7 oz) and do everything you need in the field — SWR, |Z|.  
All the advanced features that have been mentioned are good to have now and 
then, but if you’re looking for small and imminently packable for a hike into a 
noise free park or a walk to the beach, as I was, it’s a good choice.  Quick, 
easy, simple — and you don’t have to pack the manual to figure it out :-)

Grant NQ5T
K3 #2091, KX3 #8342




> On Dec 1, 2017, at 7:49 AM, w5...@comcast.net wrote:
> 
> just a quick question for the collective group here. I have built up my KX-2 
> travel kit. The first week of november I took it with me to a  cabin I leased 
> outside of Gatlinburg, TN for some portable operating when I wasn’t up in the 
> mountains hiking. I took m y Super Antenna MP-1 plus the parts to throw up a 
> full wave loop for 40M. I did throw the loop up, and it out performed the 
> MP-1 by kudo’s.  But it struck me that it might be nice to add a small 
> antenna analyzer to my kit.
> I don’t need a big full size MFJ, which I do have. But something small.  Any 
> experience here y’all?  
> 
> thanks in advance for your answers
> 
> Ronnie W5SUM
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> Message delivered to ghyoung...@gmail.com




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Re: [Elecraft] Antenna Analyzer

[Lynn W. Taylor, WB6UUT]

Because new toys are always exciting?

On 12/1/2017 11:09 AM, Jim Brown wrote:

Why must every perceived problem be resolved by buying something?

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Re: [Elecraft] Antenna Analyzer

[Jim Brown]

On 12/1/2017 4:49 AM, w5...@comcast.net wrote:

But it struck me that it might be nice to add a small antenna analyzer to my 
kit.


Why must every perceived problem be resolved by buying something? All 
Elecraft rigs, including the KX2, have an indicator for SWR that the rig 
sees. Resonance can be clearly seen by moving up and down the band to 
find it.


SWR is NOT an indicator of how well an antenna works, and antennas don't 
necessarily have to be resonant to work well! That depends on how we use 
the fundamentals of how antennas work. Especially when using improvised 
wire antennas with little or no feedline, the only thing that matters 
beyond the fundamental properties of the antenna is whether the rig can 
match it.


I'd be far more likely to drag along more "stuff" with which to rig 
improvised antennas in whatever surroundings I find myself, and to study 
the ARRL Handbook and Antenna Book to understand those fundamentals.


73, Jim K9YC



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Re: [Elecraft] Antenna Analyzer

[Mike Furrey]

I have had the Comet analyzer for a year. Although a bit pricey for the number 
of functions, what it does, it does very well and is a very solid, well built, 
and easy to use device. With that said, I will add a VNA unit to my arsenal of 
analyzers soon. 

It sure would not hurt my feeling to see what what Elecraft could do in the 
analyzer department!
73, Mike WA5POK
 

On Friday, December 1, 2017 12:35 PM, Michael Walker  
wrote:
 

 The RigExpert AA-1400 fits perfectly in a $40 Pelican 1200 case.

I have mine, charger, batteries, etc in a nice Red 1200.

I would post a pic, but you can't on this reflector.

Mike va3mw


On Fri, Dec 1, 2017 at 12:19 PM, George Thornton <
gthorn...@thorntonmostullaw.com> wrote:

> The Time Domain Reflectometer (TDR) is a hugely important feature, and is
> now available with other brands, including some of the RigExpert models.
>
> I do a lot of field work with both HF and VHF/UHF.  In my experience most
> of the problems I have encountered have been traced to cable defects of one
> kind or another.  The TDR function allows you to quickly and reliably test
> the integrity of cabling, allowing you to identify the exact location of
> the defect.
>
> I am partial to the RigExpert models, which have been reliable and
> accurate, and very easy and intuitive to use.
>
> My only quarrel with RigExpert is that they do not offer water resistant
> sealed cases.  These can get damaged in a wet environment.
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Re: [Elecraft] Antenna Analyzer

[Michael Walker]

Hi Ronnie

The TDR is a must have.  Once you start sweeping all your feedlines you
will know they are not as good as you might have thought.  :)

Twice I tossed an entire roll of heliax and twice 2 unique runs of RG213.


If anyone has feedlines older than 10 years, you might want to consider the
investment.

Mike va3mw


On Fri, Dec 1, 2017 at 12:31 PM, Ronnie Hull <w5...@comcast.net> wrote:

> Yes SMALL and PORTABLE is what I am interested in. I never wanted a TDR.
> Rig experts are fine analyzes but out of the league of what I want which is
> something to toss in my "go" bag
>
> Ronnie W5SUM
>
> Sent from my iPhone
>
> > On Dec 1, 2017, at 11:19 AM, George Thornton <
> gthorn...@thorntonmostullaw.com> wrote:
> >
> > The Time Domain Reflectometer (TDR) is a hugely important feature, and
> is now available with other brands, including some of the RigExpert models.
> >
> > I do a lot of field work with both HF and VHF/UHF.  In my experience
> most of the problems I have encountered have been traced to cable defects
> of one kind or another.  The TDR function allows you to quickly and
> reliably test the integrity of cabling, allowing you to identify the exact
> location of the defect.
> >
> > I am partial to the RigExpert models, which have been reliable and
> accurate, and very easy and intuitive to use.
> >
> > My only quarrel with RigExpert is that they do not offer water resistant
> sealed cases.   These can get damaged in a wet environment.
> >
> >
> >
> > T-Original Message-
> > From: elecraft-boun...@mailman.qth.net [mailto:elecraft-bounces@
> mailman.qth.net] On Behalf Of Jim Sheldon
> > Sent: Friday, December 1, 2017 5:39 AM
> > To: elecraft@mailman.qth.net
> > Subject: Re: [Elecraft] Antenna Analyzer
> >
> > I was introduced to the SARK-110 several years ago and besides being an
> excellent antenna analyzer, it had one feature that nobody else had (when I
> bought the SARK) and that is called a "Time Domain Reflectometer".  This
> allows you to find breaks, impedance bumps and other anomalies in cable
> runs.
> >
> > During my 20 years in the Army, I was introduced to a hugely expensive
> HP-140A oscilloscope with a TDR plug in.  We used it to find cuts in our
> buried coax where the local people were digging it up for the copper (back
> in 1967).  From that point on, I always wanted a TDR but they were way too
> expensive (even used) for a poor ham to even consider until I was
> introduced to the SARK by a good friend at the "OzarkCon" QRP convention.
> It paid for itself quickly by finding where a gopher (or
> > mole) had chewed mostly through some buried coax I had going to a
> vertical in the back yard.  The SARK's TDR pinpointed the break within a
> foot and it was probably more accurate than that as my measurements when
> following the cable were somewhat sloppy.
> >
> > It also makes a pretty decent signal generator as well, can be
> calibrated against WWV with not too much effort, but the minimum signal you
> can output is 50 microvolts (S9) so a good external step attenuator is
> needed along with double shielded cables to minimize feedthrough of
> > the SARK's output signal.   Oh yes, I did mention, it's an excellent
> > antanna analyzer as well and it will do Smith Chart plots and other
> stuff too.  You can control it with a computer via USB too.
> >
> > No financial interest in the company, just a very happy user.
> >
> > Jim - W0EB
> >
> > -- Original Message --
> > From: "John Oppenheimer" <j...@kn5l.net>
> > To: elecraft@mailman.qth.net
> > Sent: 12/1/2017 7:23:20 AM
> > Subject: Re: [Elecraft] Antenna Analyzer
> >
> >> The SARK 110 is very small with many features:
> >>
> >> http://www.sark110.com/
> >>
> >> John KN5L
> >> __
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Re: [Elecraft] Antenna Analyzer (FA-VA4)

[Wes Stewart]

What calibrations are you doing that take an hour?

You can do a master cal with lots of points in 5 minutes.

I use mine in the field all the time using a Win 10 touch screen tablet.  The 
software is phenomenal.  I've been doing network analysis since the days when 
the calibration curve was a grease pencil line on a CRT.  I (my employer) bought 
one of the first HP8510s sold to a non-governmental agency.  It cost IIRC north 
of $200K, was in a 4-foot rack cabinet and probably weighed 500 pounds.  With an 
admittedly reduced frequency range, the VNWA3 is for all practical purposes the 
equal of the '8510 and I can hold it in the palm of my hand!


With a good external frequency standard (I use a Bodnar GPSDO) it makes an 
excellent frequency counter and works as a limited function spectrum analyzer.


One other thing.  On my 160-meter inverted-L antenna I receive a couple of AM 
broadcast stations at -3dBm.  If I limit the lower sweep frequency to 1.7 MHz 
the VNWA3 is unaffected.  I suspect some of these other boxes are not so resilient.


Wes N7WS
Not associated with any of the players who designed or built this thing.  Simply 
a very satisfied customer.



On 12/1/2017 9:16 AM, Ignacy wrote:


VNWA3 covers > 1300 MHz and costs about $600 but needs a computer. Often
requires multiple calibrations requiring an hr. Has two port for filters and
beam testing. I use it only when nothing else works.


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Re: [Elecraft] Antenna Analyzer

[Mel Farrer via Elecraft]

The FG-01 is  good IF the unit has the improved 2nd harmonic suppression.  Some 
of the earlier ones only had -6 dB down 2nd.  I have two and the first one went 
back twice to fix it.
Mel, K6KBE

  From: Doug Person <d...@k0dxv.com>
 To: elecraft@mailman.qth.net 
 Sent: Friday, December 1, 2017 9:24 AM
 Subject: Re: [Elecraft] Antenna Analyzer
   
I have several antenna analyzers. The best value I think is the YouKits 
FG-01 <https://www.vibroplex.com/contents/en-us/p190.html> .  It's price 
is on the lower end of the scale. It's color display and feature set are 
outstanding. I also have the MFJ 223 which is very compact and highly 
functional. These two are particularly good for travel due to their very 
small size.

73, Doug -- K0DXV


On 12/1/17 8:34 AM, Dick Dickinson wrote:
> Thanks folks for the rundown on current small Antenna Analyzers.
>
>  
>
>  
>
> Dick - KA5KKT
>
>  
>
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Re: [Elecraft] Antenna Analyzer

[Michael Walker]

The RigExpert AA-1400 fits perfectly in a $40 Pelican 1200 case.

I have mine, charger, batteries, etc in a nice Red 1200.

I would post a pic, but you can't on this reflector.

Mike va3mw


On Fri, Dec 1, 2017 at 12:19 PM, George Thornton <
gthorn...@thorntonmostullaw.com> wrote:

> The Time Domain Reflectometer (TDR) is a hugely important feature, and is
> now available with other brands, including some of the RigExpert models.
>
> I do a lot of field work with both HF and VHF/UHF.  In my experience most
> of the problems I have encountered have been traced to cable defects of one
> kind or another.  The TDR function allows you to quickly and reliably test
> the integrity of cabling, allowing you to identify the exact location of
> the defect.
>
> I am partial to the RigExpert models, which have been reliable and
> accurate, and very easy and intuitive to use.
>
> My only quarrel with RigExpert is that they do not offer water resistant
> sealed cases.   These can get damaged in a wet environment.
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Re: [Elecraft] Antenna Analyzer

[Ronnie Hull]

Yes SMALL and PORTABLE is what I am interested in. I never wanted a TDR. Rig 
experts are fine analyzes but out of the league of what I want which is 
something to toss in my "go" bag

Ronnie W5SUM

Sent from my iPhone

> On Dec 1, 2017, at 11:19 AM, George Thornton 
> <gthorn...@thorntonmostullaw.com> wrote:
> 
> The Time Domain Reflectometer (TDR) is a hugely important feature, and is now 
> available with other brands, including some of the RigExpert models.
> 
> I do a lot of field work with both HF and VHF/UHF.  In my experience most of 
> the problems I have encountered have been traced to cable defects of one kind 
> or another.  The TDR function allows you to quickly and reliably test the 
> integrity of cabling, allowing you to identify the exact location of the 
> defect.
> 
> I am partial to the RigExpert models, which have been reliable and accurate, 
> and very easy and intuitive to use.  
> 
> My only quarrel with RigExpert is that they do not offer water resistant 
> sealed cases.   These can get damaged in a wet environment.
> 
> 
> 
> T-Original Message-
> From: elecraft-boun...@mailman.qth.net 
> [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Jim Sheldon
> Sent: Friday, December 1, 2017 5:39 AM
> To: elecraft@mailman.qth.net
> Subject: Re: [Elecraft] Antenna Analyzer
> 
> I was introduced to the SARK-110 several years ago and besides being an 
> excellent antenna analyzer, it had one feature that nobody else had (when I 
> bought the SARK) and that is called a "Time Domain Reflectometer".  This 
> allows you to find breaks, impedance bumps and other anomalies in cable runs.
> 
> During my 20 years in the Army, I was introduced to a hugely expensive 
> HP-140A oscilloscope with a TDR plug in.  We used it to find cuts in our 
> buried coax where the local people were digging it up for the copper (back in 
> 1967).  From that point on, I always wanted a TDR but they were way too 
> expensive (even used) for a poor ham to even consider until I was introduced 
> to the SARK by a good friend at the "OzarkCon" QRP convention.  It paid for 
> itself quickly by finding where a gopher (or
> mole) had chewed mostly through some buried coax I had going to a vertical in 
> the back yard.  The SARK's TDR pinpointed the break within a foot and it was 
> probably more accurate than that as my measurements when following the cable 
> were somewhat sloppy.
> 
> It also makes a pretty decent signal generator as well, can be calibrated 
> against WWV with not too much effort, but the minimum signal you can output 
> is 50 microvolts (S9) so a good external step attenuator is needed along with 
> double shielded cables to minimize feedthrough of 
> the SARK's output signal.   Oh yes, I did mention, it's an excellent 
> antanna analyzer as well and it will do Smith Chart plots and other stuff 
> too.  You can control it with a computer via USB too.
> 
> No financial interest in the company, just a very happy user.
> 
> Jim - W0EB
> 
> -- Original Message --
> From: "John Oppenheimer" <j...@kn5l.net>
> To: elecraft@mailman.qth.net
> Sent: 12/1/2017 7:23:20 AM
> Subject: Re: [Elecraft] Antenna Analyzer
> 
>> The SARK 110 is very small with many features:
>> 
>> http://www.sark110.com/
>> 
>> John KN5L
>> __
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Re: [Elecraft] Antenna Analyzer

[George Thornton]

The Time Domain Reflectometer (TDR) is a hugely important feature, and is now 
available with other brands, including some of the RigExpert models.

I do a lot of field work with both HF and VHF/UHF.  In my experience most of 
the problems I have encountered have been traced to cable defects of one kind 
or another.  The TDR function allows you to quickly and reliably test the 
integrity of cabling, allowing you to identify the exact location of the defect.

I am partial to the RigExpert models, which have been reliable and accurate, 
and very easy and intuitive to use.  

My only quarrel with RigExpert is that they do not offer water resistant sealed 
cases.   These can get damaged in a wet environment.



T-Original Message-
From: elecraft-boun...@mailman.qth.net 
[mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Jim Sheldon
Sent: Friday, December 1, 2017 5:39 AM
To: elecraft@mailman.qth.net
Subject: Re: [Elecraft] Antenna Analyzer

I was introduced to the SARK-110 several years ago and besides being an 
excellent antenna analyzer, it had one feature that nobody else had (when I 
bought the SARK) and that is called a "Time Domain Reflectometer".  This allows 
you to find breaks, impedance bumps and other anomalies in cable runs.

During my 20 years in the Army, I was introduced to a hugely expensive HP-140A 
oscilloscope with a TDR plug in.  We used it to find cuts in our buried coax 
where the local people were digging it up for the copper (back in 1967).  From 
that point on, I always wanted a TDR but they were way too expensive (even 
used) for a poor ham to even consider until I was introduced to the SARK by a 
good friend at the "OzarkCon" QRP convention.  It paid for itself quickly by 
finding where a gopher (or
mole) had chewed mostly through some buried coax I had going to a vertical in 
the back yard.  The SARK's TDR pinpointed the break within a foot and it was 
probably more accurate than that as my measurements when following the cable 
were somewhat sloppy.

It also makes a pretty decent signal generator as well, can be calibrated 
against WWV with not too much effort, but the minimum signal you can output is 
50 microvolts (S9) so a good external step attenuator is needed along with 
double shielded cables to minimize feedthrough of 
the SARK's output signal.   Oh yes, I did mention, it's an excellent 
antanna analyzer as well and it will do Smith Chart plots and other stuff too.  
You can control it with a computer via USB too.

No financial interest in the company, just a very happy user.

Jim - W0EB

-- Original Message --
From: "John Oppenheimer" <j...@kn5l.net>
To: elecraft@mailman.qth.net
Sent: 12/1/2017 7:23:20 AM
Subject: Re: [Elecraft] Antenna Analyzer

>The SARK 110 is very small with many features:
>
>http://www.sark110.com/
>
>John KN5L
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Re: [Elecraft] Antenna Analyzer

[Doug Person]

I have several antenna analyzers. The best value I think is the YouKits 
FG-01  .  It's price 
is on the lower end of the scale. It's color display and feature set are 
outstanding. I also have the MFJ 223 which is very compact and highly 
functional. These two are particularly good for travel due to their very 
small size.


73, Doug -- K0DXV


On 12/1/17 8:34 AM, Dick Dickinson wrote:

Thanks folks for the rundown on current small Antenna Analyzers.

  

  


Dick - KA5KKT

  


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Re: [Elecraft] Antenna Analyzer (FA-VA4)

[Mark Goldberg]

I have one more suggestion. I have a MiniVNA Tiny, expensive at about $600,
but it is a full two port Vector Network Analyzer in a 2.5" X 2.5" X 1" box
connected via USB. It has both a computer app and a phone app to run it. I
have taken it out in the field where I would never consider taking a 75 lb
VNA. I have used it to analyze antennas, filters, transmission lines and to
characterize caps and inductors over frequency.

73,

Mark
W7MLG

On Fri, Dec 1, 2017 at 9:16 AM, Ignacy  wrote:

> The choice of analyzers is not that simple unless cheap price is the only
> factor.
>
> I have four analyzers: Rigexpert 230Pro, FA-VA4, VNWA3 and Mini60.
>
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Re: [Elecraft] Antenna Analyzer (FA-VA4)

[Ignacy]

The choice of analyzers is not that simple unless cheap price is the only
factor.

I have four analyzers: Rigexpert 230Pro, FA-VA4, VNWA3 and Mini60.

Rigexpert covers up to 230 MHz and costs about $500. It is the easiest to
use and has the most functionality. Less accurate because it does not have
OLS calibration and is pretty big, but new models (Zoom) have calibration
and are much lighter. Seems rain resistant. Coax testing for short and
length is a blessing. I use it most of the time. 

VNWA3 covers > 1300 MHz and costs about $600 but needs a computer. Often
requires multiple calibrations requiring an hr. Has two port for filters and
beam testing. I use it only when nothing else works. 

FA-VA4 works up to 100 MHz and is very accurate after good calibration
(included 50 Ohm load is not too good). Light but not the smallest. Getting
things done takes many buttons. Not waterproof. Also. soldering is tricky
and I wonder whether bad soldering will show up one time. I use FA-VA4 for
portable measurements where accuracy is important. For instance impedance of
inv L on 160m. Measure impedance, prepare appropriate coil, and no extra
fine tuning needed. Also very useful to measure properties of toroids across
frequency. 

I also have mini60 that works up to 60 MHz, is very small, can be charged
via USB, and interfaces with Android phone, and costs $100. SWR accuracy is
good but X is not. I leave it for travel. 





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Re: [Elecraft] Antenna Analyzer

[Igor Sokolov]

+1

73, Igor UA9CDC


01.12.2017 18:23, John Oppenheimer пишет:

The SARK 110 is very small with many features:

http://www.sark110.com/

John KN5L
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Re: [Elecraft] Antenna Analyzers

[Mike Lichtman via Elecraft]

It would be nice if Elecraft had their own branded analyzer. It could be a semi 
kit like the 
graphing one being sold from Germany. 73 Mike KF6KXG 
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Re: [Elecraft] Antenna Analyzer (FA-VA4)

[Peter Eijlander (PA0PJE)]

John,

I saw that one on FunkAmateur/Box73, they sell the kit.

What appeals me is the price (155 euro), the simplicity the way it can 
be built, the features, apart form being a nice graphical analyzer it's 
much more like a signal generator from 100 kHz to 100 MHz. It's readable 
in direct sunlight due to it's LCD type (like te one on a K3 even the 
same backlight color) And the power supply: it uses two AA cells.


I have it and I can say: Highly recommended.

72/73
Peter - PA0PJE

PS No connection to FA/Box73...


Op 2017-12-01 13:57 schreef John Harper:

I highly recommend this one - cost effective, easy to build and compares
favorable to more expensive models:
https://ae5x.blogspot.com/2017/10/new-antenna-analyzer.html

More here:
https://ae5x.blogspot.com/2017/11/a-brief-comparison-of-two-antenna.html


73,
John AE5X
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Re: [Elecraft] Antenna Analyzer

[Mike Cox]

These were very useful devices from "back in the day". I see a couple 
available on ebay by searching for "Palomar noise bridge"


Mike, AB9V


On 12/1/2017 7:49 AM, w5...@comcast.net wrote:

just a quick question for the collective group here. I have built up my KX-2 
travel kit. The first week of november I took it with me to a  cabin I leased 
outside of Gatlinburg, TN for some portable operating when I wasn’t up in the 
mountains hiking. I took m y Super Antenna MP-1 plus the parts to throw up a 
full wave loop for 40M. I did throw the loop up, and it out performed the MP-1 
by kudo’s.  But it struck me that it might be nice to add a small antenna 
analyzer to my kit.
I don’t need a big full size MFJ, which I do have. But something small.  Any 
experience here y’all?

thanks in advance for your answers

Ronnie W5SUM
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Re: [Elecraft] Antenna Analyzer

[Dave Cole (NK7Z)]

Having a graph of the entire band is so helpful, The AA series make for 
a single button test...  You adjust, then hit the go button.  You then 
see exactly what happened to your SWR dip.  Did it go too far, not far 
enough, etc.


Others, you have to fuss with knobs to find the dip, then remember the 
last reading...  Seems like a small item, but it is massively helpful 
when tuning up an antenna.  Takes me 20 minutes to tune a 6BTV now.  For 
an example of charts the AA series puts to computers see a short blog 
post I did on tuning up a 6BTV at:


http://nk7z.net/notes-on-tuning-a-6btv/

73s and thanks,
Dave
NK7Z
http://www.nk7z.net

On 12/01/2017 05:25 AM, Michael Walker wrote:

I would have to agree.  the Rigexpert AA series.

Well made, drop proof and stand alone.

Mike va3mw


On Fri, Dec 1, 2017 at 8:23 AM, John Oppenheimer  wrote:


The SARK 110 is very small with many features:

http://www.sark110.com/

John KN5L
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Re: [Elecraft] Antenna Analyzer

[Bob N3MNT]

I have had good luck with this one.  Very small and works well.
https://youkits.com/products/youkits-fg-01-1-72mhz-antenna-analyser



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Re: [Elecraft] Antenna Analyzer

[Jim Sheldon]

I was introduced to the SARK-110 several years ago and besides being an 
excellent antenna analyzer, it had one feature that nobody else had 
(when I bought the SARK) and that is called a "Time Domain 
Reflectometer".  This allows you to find breaks, impedance bumps and 
other anomalies in cable runs.


During my 20 years in the Army, I was introduced to a hugely expensive 
HP-140A oscilloscope with a TDR plug in.  We used it to find cuts in our 
buried coax where the local people were digging it up for the copper 
(back in 1967).  From that point on, I always wanted a TDR but they were 
way too expensive (even used) for a poor ham to even consider until I 
was introduced to the SARK by a good friend at the "OzarkCon" QRP 
convention.  It paid for itself quickly by finding where a gopher (or 
mole) had chewed mostly through some buried coax I had going to a 
vertical in the back yard.  The SARK's TDR pinpointed the break within a 
foot and it was probably more accurate than that as my measurements when 
following the cable were somewhat sloppy.


It also makes a pretty decent signal generator as well, can be 
calibrated against WWV with not too much effort, but the minimum signal 
you can output is 50 microvolts (S9) so a good external step attenuator 
is needed along with double shielded cables to minimize feedthrough of 
the SARK's output signal.   Oh yes, I did mention, it's an excellent 
antanna analyzer as well and it will do Smith Chart plots and other 
stuff too.  You can control it with a computer via USB too.


No financial interest in the company, just a very happy user.

Jim - W0EB

-- Original Message --
From: "John Oppenheimer" <j...@kn5l.net>
To: elecraft@mailman.qth.net
Sent: 12/1/2017 7:23:20 AM
Subject: Re: [Elecraft] Antenna Analyzer


The SARK 110 is very small with many features:

http://www.sark110.com/

John KN5L
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Re: [Elecraft] Antenna Analyzer

[Michael Walker]

I would have to agree.  the Rigexpert AA series.

Well made, drop proof and stand alone.

Mike va3mw


On Fri, Dec 1, 2017 at 8:23 AM, John Oppenheimer  wrote:

> The SARK 110 is very small with many features:
>
> http://www.sark110.com/
>
> John KN5L
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Re: [Elecraft] Antenna Analyzer

[John Oppenheimer]

The SARK 110 is very small with many features:

http://www.sark110.com/

John KN5L
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Re: [Elecraft] Antenna Analyzer

[Dave Cole (NK7Z)]

The AA series from Rigexpert is also very lightweight...

73s and thanks,
Dave
NK7Z
http://www.nk7z.net

On 12/01/2017 04:53 AM, John Stengrevics wrote:

The RigExpert line is small.

73,

John
WA1EAZ


On Dec 1, 2017, at 7:49 AM,   wrote:

just a quick question for the collective group here. I have built up my KX-2 
travel kit. The first week of november I took it with me to a  cabin I leased 
outside of Gatlinburg, TN for some portable operating when I wasn’t up in the 
mountains hiking. I took m y Super Antenna MP-1 plus the parts to throw up a 
full wave loop for 40M. I did throw the loop up, and it out performed the MP-1 
by kudo’s.  But it struck me that it might be nice to add a small antenna 
analyzer to my kit.
I don’t need a big full size MFJ, which I do have. But something small.  Any 
experience here y’all?

thanks in advance for your answers

Ronnie W5SUM
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Re: [Elecraft] Antenna Analyzer

[John Stengrevics]

The RigExpert line is small.

73,

John
WA1EAZ

> On Dec 1, 2017, at 7:49 AM,   wrote:
> 
> just a quick question for the collective group here. I have built up my KX-2 
> travel kit. The first week of november I took it with me to a  cabin I leased 
> outside of Gatlinburg, TN for some portable operating when I wasn’t up in the 
> mountains hiking. I took m y Super Antenna MP-1 plus the parts to throw up a 
> full wave loop for 40M. I did throw the loop up, and it out performed the 
> MP-1 by kudo’s.  But it struck me that it might be nice to add a small 
> antenna analyzer to my kit.
> I don’t need a big full size MFJ, which I do have. But something small.  Any 
> experience here y’all?  
> 
> thanks in advance for your answers
> 
> Ronnie W5SUM
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Re: [Elecraft] Antenna 2

[Bob McGraw K4TAX]

Either put a small 50 ohm load or leave it open.  A short to ground may cause a 
PA device failure. 

Bob, K4TAX


Sent from my iPhone

> On Nov 28, 2017, at 5:19 PM, Jim Rhodes  wrote:
> 
> Well if you accidentally transmit into it an open might be better than a
> short. Did you at least disable it using the utility program?
> 
> Jim Rhodes
> K0XU
> 
>> On Nov 28, 2017 16:52, "Paul Ormandy"  wrote:
>> 
>> Thanks for the replies. Hadn't thought of its use for sub rx or dummy load.
>> I have grounded out the connector with a plug hooked directly to the
>> receiver grounding terminal.
>> 
>> Paul
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Re: [Elecraft] Antenna 2

[Jim Rhodes]

Well if you accidentally transmit into it an open might be better than a
short. Did you at least disable it using the utility program?

Jim Rhodes
K0XU

On Nov 28, 2017 16:52, "Paul Ormandy"  wrote:

> Thanks for the replies. Hadn't thought of its use for sub rx or dummy load.
> I have grounded out the connector with a plug hooked directly to the
> receiver grounding terminal.
>
> Paul
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Re: [Elecraft] Antenna 2

[Gary Smith]

I think he was asking what Don answered 
to.

Gary
KA1J

> 
> That doesn't explain how he expects the rig to short out the port for
> Ant 2 . .. WHEN IT HAS BEEN SELECTED ... just because there is no
> actual antenna connected to it.  I don't get the reasoning behind the
> original query.
> 
> Dave   AB7E
> 
> 
> On 11/28/2017 7:04 AM, K9ZTV wrote:
> > We hook dummy loads to ANT 2 on all our K3s during FD to prevent
> > inadvertent transmissions when no antenna is connected to it.  The
> > ATU TUNE button is immediately above the ANT button and
> > fat-fingered/far-sighted ops unfamiliar with the K3 have been known
> > to hit the wrong one, especially on the higher bands where the noise
> > floor makes it difficult to detect the absence of an antenna.
> >
> > 73,
> >
> > Kent  K9ZTV
> >
> >
> >
> >> On Nov 28, 2017, at 7:40 AM, David Gilbert
> >>  wrote:
> >>
> >>
> >> If you selected Ant 2 it wouldn't have been "unused".   How is the
> >> rig supposed to know you don't have anything physically connected
> >> to that port?
> >>
> >> Dave   AB7E
> >
> 
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Re: [Elecraft] Antenna 2

[Michael Eberle]

I believe he is actually operating into an antenna on Ant1 port. He 
switched to Ant2 to check the port isolation and would obviously switch 
back to Ant1 to operate.  I doubt grounding the non-selected antenna 
port would make any difference on TX and some use both ports for 
diversity RX.  If protecting the radio is the concern then I believe as 
Kent stated, the dummy load would be the best option.


Mike  KI0HA


On 11/28/2017 12:01, David Gilbert wrote:


That doesn't explain how he expects the rig to short out the port for 
Ant 2 . .. WHEN IT HAS BEEN SELECTED ... just because there is no 
actual antenna connected to it.  I don't get the reasoning behind the 
original query.


Dave   AB7E


On 11/28/2017 7:04 AM, K9ZTV wrote:
We hook dummy loads to ANT 2 on all our K3s during FD to prevent 
inadvertent transmissions when no antenna is connected to it.  The 
ATU TUNE button is immediately above the ANT button and 
fat-fingered/far-sighted ops unfamiliar with the K3 have been known 
to hit the wrong one, especially on the higher bands where the noise 
floor makes it difficult to detect the absence of an antenna.


73,

Kent  K9ZTV



On Nov 28, 2017, at 7:40 AM, David Gilbert 
 wrote:



If you selected Ant 2 it wouldn't have been "unused".   How is the 
rig supposed to know you don't have anything physically connected to 
that port?


Dave   AB7E




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Re: [Elecraft] Antenna 2

[David Gilbert]

That doesn't explain how he expects the rig to short out the port for 
Ant 2 . .. WHEN IT HAS BEEN SELECTED ... just because there is no actual 
antenna connected to it.  I don't get the reasoning behind the original 
query.


Dave   AB7E


On 11/28/2017 7:04 AM, K9ZTV wrote:

We hook dummy loads to ANT 2 on all our K3s during FD to prevent inadvertent 
transmissions when no antenna is connected to it.  The ATU TUNE button is 
immediately above the ANT button and fat-fingered/far-sighted ops unfamiliar 
with the K3 have been known to hit the wrong one, especially on the higher 
bands where the noise floor makes it difficult to detect the absence of an 
antenna.

73,

Kent  K9ZTV




On Nov 28, 2017, at 7:40 AM, David Gilbert  wrote:


If you selected Ant 2 it wouldn't have been "unused".   How is the rig supposed 
to know you don't have anything physically connected to that port?

Dave   AB7E




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Re: [Elecraft] Antenna 2

[KENT TRIMBLE]

We hook dummy loads to ANT 2 on all our K3s during FD to prevent 
inadvertent transmissions when no antenna is connected to it.


The ATU TUNE button is immediately above the ANT button and 
fat-fingered/far-sighted ops unfamiliar with the K3 have been known to 
hit the wrong one, especially on the higher bands where the noise floor 
sometimes makes it difficult to detect the absence of an antenna.


73,

Kent   K9ZTV
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Re: [Elecraft] Antenna 2

[Walter Underwood]

I keep my dummy load connected to ANT 2 on my KXPA100. Might as well have it 
connected somewhere.

wunder
K6WRU
Walter Underwood
CM87wj
http://observer.wunderwood.org/ (my blog)

> On Nov 28, 2017, at 6:22 AM, Don Wilhelm  wrote:
> 
> Paul,
> 
> There is some stray coupling between ANT1 and ANT2, but no direct path.
> The unused antenna is not grounded.  One reason is that it can be used to 
> feed the subRX AUX ANT input when using diversity.
> 
> 73,
> Don W3FPR
> 
> On 11/28/2017 2:36 AM, Paul Ormandy wrote:
>> Hi all,
>> When messing around today with antennas, I had my aerial connected only 
>> to
>> Ant 1 and discovered that when selected, Ant 2 was capable of receiving
>> signals with no antenna connected to it, albeit at a much reduced 
>> signal. I would have thought the unused
>> port would have been earthed out??
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Re: [Elecraft] Antenna 2

[Don Wilhelm]

Paul,

There is some stray coupling between ANT1 and ANT2, but no direct path.
The unused antenna is not grounded.  One reason is that it can be used 
to feed the subRX AUX ANT input when using diversity.


73,
Don W3FPR

On 11/28/2017 2:36 AM, Paul Ormandy wrote:

Hi all,

     When messing around today with antennas, I had my aerial connected 
only to
     Ant 1 and discovered that when selected, Ant 2 was capable of 
receiving
     signals with no antenna connected to it, albeit at a much reduced 
signal. I would have thought the unused

     port would have been earthed out??

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Re: [Elecraft] Antenna 2

[Bob N3MNT]

If you do not have anything on Ant 2 I suggest using the config utility to
disable Ant 2 for now.  This will prevent accidentally selecting Ant 2 and
trying to transmit.  



--
Sent from: http://elecraft.365791.n2.nabble.com/
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Re: [Elecraft] Antenna 2

[David Gilbert]

If you selected Ant 2 it wouldn't have been "unused".   How is the rig 
supposed to know you don't have anything physically connected to that port?


Dave   AB7E


On 11/28/2017 12:36 AM, Paul Ormandy wrote:

Hi all,

    When messing around today with antennas, I had my aerial connected 
only to
    Ant 1 and discovered that when selected, Ant 2 was capable of 
receiving
    signals with no antenna connected to it, albeit at a much reduced 
signal. I would have thought the unused

    port would have been earthed out??
    Paul



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Re: [Elecraft] ANTENNA QUESTION

[rich hurd WC3T]

As Wayne N6KR mentioned yesterday,

"I’ll be speaking at Pacificon's antenna symposium tomorrow (Friday, Oct.
20th). My presentation, from 3:30 to 4:30 PM, is on antennas for
ultra-portable HF operation. This talk was a late addition, a previous
speaker having dropped out.

If you’re interested in attending the symposium, check the website (
pacificon.org). Tickets must be purchase in advance.

As part of my talk I’ll be discussing a new portable antenna, the Elecraft
AX1, designed specifically for the KX2 and KX3. We’ll also be showing the
prototype at our booth.

We’re not taking orders for the AX1 yet, so please don’t call Elecraft Hq
about it :)  That said, I’ll be happy to send out an early draft of the FAQ
on request. Please email me directly.

73,
Wayne
N6KR"

---
72,
Rich Hurd / WC3T / DMR: 3142737
PA Army MARS, Northampton County RACES, EPA-ARRL Public Information Officer
for Scouting
Latitude: 40.761621 Longitude: -75.288988  (40°45.68' N 75°17.33' W) Grid:
*FN20is*


On Fri, Oct 20, 2017 at 3:51 PM, Gerry Miller  wrote:

>  WHAT IS THE AX1 THAT I HAVE READ COMMENTS ABOUT.  ARE THERE FURTHER
> DESCRIPTIONS OR PHOTO'S RE THIS ANTENNA?GERRY MILLER, aa...@juno.com
> 
> 1 Simple Trick Removes Eye Bags & Lip Lines In Seconds
> Fit Mom Daily
> http://thirdpartyoffers.juno.com/TGL3141/59ea54012a29154013571st03vuc
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Re: [Elecraft] Antenna Problems with K3 firmware 5.57

[Bill Frantz]

On 4/1/17 at 6:44 AM, elecraft@mailman.qth.net (Dick Bacon via 
Elecraft) wrote:



... that was to check and tighten the three screws on the bottom cover
for the LPA transistors (p63 in assembly manual).


I got the same advice, but mine were quite tight. If you have 
problems with erratic SWR or Power readings, check those screws 
before sending an email to support. :-)


An update on the broadcast station interference problem aka the 
antenna problem.


I looked at KLIV's data in the FCC database (thanks Jim K9YC for 
the links). It turns out that after sundown, KLIV changes the 
pattern of its antennas to put most of the power directly toward 
my QTH. 
. 
No wonder I have a problem.


Jack, W6FB wondered how long a coax stub for 1590 KHz would be. 
A quick back of the envelope calculation came up with a bit more 
than 100 feet. I pulled out a piece of RG-58 labeled 104' and 
hooked it up as a stub. The problem get a lot better, but it had 
a noticeable effect on the bottom end of the 160M band. The stub 
is far from being a notch filter.


Adding another piece of coax got it below the 160M band, but I 
worry about suppression of odd harmonics at higher frequencies. 
I think I have used the antenna for QSOs on every amateur band 
from 160M to 6M inclusive. So on to something that took longer 
than 10 minutes to try.


I dug through the junk box and found a 560 pF 1KV cap and a 
T68-2 core. Quality time with the ARRL Handbook said to use 56 
turns on the core, which I did with some #30 wire. So far, knock 
on wood, this seems to get proper power output on the entire 
160M band. And the core only gets warm if you hold the key down 
for a long time. I'll need thicker wire before the next 160M 
RTTY contest.


73 Bill AE6JV

---
Bill Frantz| Security is like Government  | Periwinkle
(408)356-8506  | services. The market doesn't | 16345 
Englewood Ave
www.pwpconsult.com | want to pay for them.| Los Gatos, 
CA 95032


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Re: [Elecraft] Antenna Problems with K3 firmware 5.57

[Dick Bacon via Elecraft]

This may not be directly related, but I had power indication problems in
that the SWR and FWD power readings on my K3 had become erratic with surging
of indicated power on CW from a setting of 50W up to 100W and over, yet a
constant tune signal was rock steady at 50W. I thought it was an
intermittent antenna problem, then switched to it being an SWR measurement
problem.  I tried everything including two updates of firmware which had
temporary benefit but didn't last. Wrote to Elecraft and carried out all
checks they recommended except (to my embarrassment) for one which I thought
unlikely.  There is a lesson here!!  Yes, it did turn out to be the real
cause and that was to check and tighten the three screws on the bottom cover
for the LPA transistors (p63 in assembly manual). 

 

My assumption now is therefore that loose mountings / grounding may have
been causing erratic reactive components in the LPA power circuitry leading
to sprogs which trigger the much improved VSWR sense circuitry to hunt but
never actually find a stable point except when on steady tune up carrier.
Incidentally it didn't show up when running low power (10W) using the LPA
only. It is so easy to jump to the wrong conclusions; in this case where
improvements in the SWR sense loop performance was masking the growing
problem with poor ground of key LPA components. After re-reading the
Elecraft advice again I did actually check the screws (they were very loose)
and tightened them up it all went back to normal.  Disconnecting the cables
from the K3 to connect to the PC for the firmware uploads must have
temporarily disturbed the seating of the LPA screws giving a false and
temporary indication of a fix.  A regular ragchew contact reported much
cleaner rf signal as seen on a pan display after the repair.

 

Dick G3WRJ

 

 

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Re: [Elecraft] Antenna Problems with K3 firmware 5.57

[Jim Brown]

I agree, and you'll need pretty high Q components. Lots of good 
capacitor choices at HSC. Another suggestion though. KLIV is omni during 
the day, but strongly directional at night. This is quite common on the 
AM band. I suggest that you make your strength measurements at night. 
Depending on where you are, a different station may be stronger at night 
when you're working 160.  Here's a link to the FCC website where you can 
look up technical details of any broadcast station.


 https://www.fcc.gov/media/radio/am-query

And here's the listing for KLIV Notice the links near the bottom of each 
listing showing pattern and coverage area.  The wild distortions in the 
coverage area are the result of varying ground conductivity -- the big 
thumb over the Bay is because it's sea water.


https://transition.fcc.gov/fcc-bin/amq?list=0=19531

Another thought, Bill.  A horizontal 160M antenna at 20 ft is a real 
worm-warmer, and while 40 ft is better, it's still very low. If you can 
do some sort of counterpoise, a top loaded vertical, even if it's short, 
could work a lot better.


Here are slides for the talk I've done several times about getting on 
160M. It's mostly about antennas and counterpoises. You might have heard 
it. :)  The K2AV folded counterpoise seems to work pretty well, and 
doesn't take a lot of space.


73, Jim K9YC

On Fri,3/31/2017 2:50 PM, Walter Underwood wrote:

Use a series-tuned “wave trap” on KLIV’s frequency across your feedline.



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Re: [Elecraft] Antenna Problems with K3 firmware 5.57

[Don Wilhelm]

Bill,

I would try an L/C series trap at the frequency of your offending BC 
band station across your antenna feedline.  That should not be dependent 
on the IN/OUT impedance requirement of the DX Engineering BC band filter.


73,
Don W3FPR

On 3/31/2017 5:36 PM, Bill Frantz wrote:



The voltage is most likely from AM broadcast stations. The strongest
station, measured with the P3, is KLIV (5000W) about 8 miles from my QTH.



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Re: [Elecraft] Antenna Problems with K3 firmware 5.57

[Walter Underwood]

Use a series-tuned “wave trap” on KLIV’s frequency across your feedline. That 
will short out the feedline at that frequency. It will add some inductive load 
above the resonant frequency, but the ATU can deal with that.

The components need to be rated for the transmission line voltages, but they 
probably won’t be handling a lot of current.

wunder
K6WRU
Walter Underwood
CM87wj
http://observer.wunderwood.org/ (my blog)

> On Mar 31, 2017, at 2:36 PM, Bill Frantz  wrote:
> 
> I have a 160M full length dipole. The center used to be at about 40 feet. 
> About the time version 5.57 of the firmware came out, the mast supporting the 
> center feed point broke and I re-rigged with the center at about 22 feet. (I 
> hate debugging when there were two changes.)
> 
> Measurement of the lowered antenna with a MFJ-259B antenna analyzer show 
> 1.2:1 SWR match at 1.87 KHz with 2,5:1 and 3.3:1 at the band edges from the 
> shack. Because of the mismatch at the band ends, I usually use the antenna 
> using the KAT3A tuner installed in my K3. (I don't have similar figures for 
> the higher antenna, but the SWR curve matches the computer model.)
> 
> I used the antenna with modest success including 10 DXCCs and 41 US states 
> confirmed.
> 
> When I installed 5.57, I noticed significant power drops on 160M, stepping 
> down from 100W to 25W and 50W. With the help of Elecraft support, we have 
> concluded that the antenna is irritating the new firmware feature:
> 
>K3 MCU 5.57 / DSP 2.88 / FPF 1.26, 2-16-2017
> 
>* FASTER RESPONSE TO HIGH REFLECTED POWER. The transceiver will now reduce
>drive more quickly when transient conditions cause excessive reflected
>power. This roll-back response does not change the set power level (PWR
>knob); instead, it reduces the drive to get below the reflected power
>limit. This means that once a better match is restored (such as when using
>an antenna tuner), the set power level will automatically be restored.
> 
> When I backed off to version 5.50, 160M performance seems to have gone back 
> to what it was.
> 
> Measuring the open-circuit voltage on the antenna feed line with a 
> oscilloscope shows about 600mV peak to peak. I estimate, based on eyeballing 
> the trace and measuring other antennas, that about 200mV of that is 60 cycle 
> hum. Elecraft support thinks this is enough voltage to affect the internal K3 
> SWR bridge.
> 
> The voltage is most likely from AM broadcast stations. The strongest station, 
> measured with the P3, is KLIV (5000W) about 8 miles from my QTH.
> 
> 
> So now, the question is what to do about the problem. Several things I have 
> been able to think of are:
> 
> * Use a broadcast band filter. DXEngineering has one that will handle 200W, 
> but it wants 50 ohms impedance on both ends. Therefore it is recommended to 
> install it between the power amp (internal to the K3) and the tuner (also 
> internal to the K3). I might be tempted to insert one in the K3, but the 
> tuner and power amp are connected through a header, not a simple cable I 
> could reroute to install the filter.
> 
> * Get a KAT500 and the filter. Expensive, but straight forward.
> 
> * Sometimes the power remains at 100W when the internal tuner is in bypass 
> mode, but not always. It might remain stable enough for QSO, but flipping 
> back and fourth seems to be a pain.
> 
> Does anyone have any suggestions?
> 
> Thanks - Bill AE6JV
> 
> ---
> Bill Frantz| Concurrency is hard. 12 out  | Periwinkle
> (408)356-8506  | 10 programmers get it wrong. | 16345 Englewood Ave
> www.pwpconsult.com |- Jeff Frantz | Los Gatos, CA 95032
> 
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Re: [Elecraft] Antenna switches

[Robert Nobis]

I use Diamond Antenna Switches originally purchased in Japan with good results. 

See http://www.diamond-ant.co.jp/english/amateur/equipment/equipment5_swi.html 
. The claimed isolation up to 200MHz 
for the two-port CX210A switch is 70dB. I have not actually measured the ones I 
have.

These are available form DX Engineering for about $50.00

Oh, I do not have any connection with either Diamond Antennas or DX Engineering.

Bob Nobis 
n7...@nobis.net


> On Jan 2, 2017, at 20:23, Don Wilhelm  wrote:
> 
> Jim,
> 
> The most important factor when talking about connecting multiple transceivers 
> to antennas is isolation.
> The real question is just how much RF energy will leak back into the 
> non-transmit transceiver.
> Yes, there is the possibility of damage to the receiving circuits and T/R 
> switch of the receive transceive that is just supposed to be listening if it 
> gets too much RF at its receive input.
> 
> That is what the real discussion is all about.  The amount of isolation 
> required in the switch depends on the power level.  If you are talking about 
> 100 watts power from the transmitter, 40 dB isolation is likely OK, but at 
> higher powers, you will need more isolation.
> 
> 73,
> Don W3FPR
> 
> On 1/2/2017 9:53 PM, Jim Miller wrote:
>> Off topic.  Sorry.  What are the functional disadvantages that make it
>> apparently undesirable to build an antenna switch that is a crossover 2
>> radios x 2 antennas?  What if you only used one path at a time but could
>> switch them easily?  Crosstalk?  Is it so strong as to damage the other
>> radio?  Is it not possible to achieve acceptable compatibility with 2 radios
>> and 2 antennas?  Or to swap amplifiers between two radios and two antennas
>> by placing one on the input and another on the output of the amplifiers?  Or
>> to swap in the better antenna for a short contact that you just can't seem
>> to make on the current one?
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Re: [Elecraft] Antenna switches

[Jim N7US]

That switch is rated at 2500W PEP but only 1000W CW.  Has anyone used them
at 1500W CW or RTTY?

73, Jim N7US

-Original Message-

Let's add some real numbers.

I have a mechanical A/B switch DIAWA Model CS-201.  Fairly inexpensive.
Internally, it has a cavity design to provide isolation between the ports.

Using an HP signal generator and an HP-3586C selective level meter the
isolation of the switch was measured.  The used port was terminated in a
50 ohm dummy load.  The "open" port went into the selective level meter
which had a input Z of 50 ohms.  The HP-3586C can measure RF power levels
accurately within a few tenths of a dBm.  Differences are at least as
accurate.

Here are some numbers:
160M/80M 80 dB isolation
20M  69 dB isolation
10M  60 dB isolation
6M (by extrapolation) 46 dB.
YMMV

Note the frequency dependence.

This switch provides the 40 dB isolation necessary.

I have no connection with DIAWA but was interested in this topic.

I suspect there is some real junk out there.  Obtaining 60+ dB isolation
isn't easy.

The slide switch "designs" described by some are likely in that junk
category.

If in doubt measure.  You have two rigs and an S meter.  Input .1 or 1 watt
to the switch terminated as above and look at the S meter for the rig on the
open port. Scale the results to 100 W. If it shows S9+80 dB or less, you are
likely OK.  Keep in mind many S meters are horribly inaccurate.  They tend
to be too generous at around S9.

Not knowing could be expensive.

73 de Brian/K3KO


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Re: [Elecraft] Antenna switches

[brian]

Let's add some real numbers.

I have a mechanical A/B switch DIAWA Model CS-201.  Fairly inexpensive.
Internally, it has a cavity design to provide isolation between the ports.

Using an HP signal generator and an HP-3586C selective level meter the 
isolation of the switch was measured.  The used port was terminated in a 
50 ohm dummy load.  The "open" port went into the selective level meter 
which had a input Z of 50 ohms.  The HP-3586C can measure RF power 
levels accurately within a few tenths of a dBm.  Differences are at 
least as accurate.


Here are some numbers:
160M/80M 80 dB isolation
20M  69 dB isolation
10M  60 dB isolation
6M (by extrapolation) 46 dB.
YMMV

Note the frequency dependence.

This switch provides the 40 dB isolation necessary.

I have no connection with DIAWA but was interested in this topic.

I suspect there is some real junk out there.  Obtaining 60+ dB isolation 
isn't easy.


The slide switch "designs" described by some are likely in that junk 
category.


If in doubt measure.  You have two rigs and an S meter.  Input .1 or 1 
watt to the switch terminated as above and look at the S meter for the 
rig on the open port. Scale the results to 100 W. If it shows S9+80 dB 
or less, you are likely OK.  Keep in mind many S meters are horribly 
inaccurate.  They tend to be too generous at around S9.


Not knowing could be expensive.

73 de Brian/K3KO

P.S.  In the past, I did the same measurements with coax relays.  My 
recollection: Obtaining 40 dB isolation at 10M was not possible with 
some of them.  Their internal design was not as good from an isolation 
standpoint. Lower power coax relays provided better isolation (smaller 
contact size?) than high power relays.  So be careful with coax relays.


On 1/3/2017 3:23 AM, Don Wilhelm wrote:

Jim,

The most important factor when talking about connecting multiple
transceivers to antennas is isolation.
The real question is just how much RF energy will leak back into the
non-transmit transceiver.
Yes, there is the possibility of damage to the receiving circuits and
T/R switch of the receive transceive that is just supposed to be
listening if it gets too much RF at its receive input.

That is what the real discussion is all about.  The amount of isolation
required in the switch depends on the power level.  If you are talking
about 100 watts power from the transmitter, >40 dB isolation is likely
OK, but at higher powers, you will need more isolation.

73,
Don W3FPR

On 1/2/2017 9:53 PM, Jim Miller wrote:

Off topic.  Sorry.  What are the functional disadvantages that make it
apparently undesirable to build an antenna switch that is a crossover 2
radios x 2 antennas?  What if you only used one path at a time but could
switch them easily?  Crosstalk?  Is it so strong as to damage the other
radio?  Is it not possible to achieve acceptable compatibility with 2
radios
and 2 antennas?  Or to swap amplifiers between two radios and two
antennas
by placing one on the input and another on the output of the
amplifiers?  Or
to swap in the better antenna for a short contact that you just can't
seem
to make on the current one?

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Re: [Elecraft] Antenna for 2nd receiver

[Vic Rosenthal]

I like the Pixel Loop (I think DX Engineering now makes it). It is vertically 
polarized and somewhat directional, which makes it work well for diversity. It 
works throughout the HF bands, can null local QRN, and has a feature to turn 
itself off when you transmit in order to protect its preamp and your receiver.

Vic 4X6GP

> On 3 Jan 2017, at 03:11, Paul Van Dyke  wrote:
> 
> I broke down and bought a K3s and now I'm going to have the second
> receiver. Can somebody tell me a good antenna to put on there as I will be
> using a TH11DX as the main antenna
> 
> Thank you
> Paul - KB9AVO
> 
> 
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