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80 Meter loop question

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Clay Autery

80 Meter loop question

Does anyone have any information or a link to information data on an 80
meter loop's complex impedance and VSWR values across the HF bands?

R, X, VSWR from say 3.5-30MHz or better 1.0-54 MHz, measurements taken
at the loop ends with a short jumper, not a long feed-line. Preferably
with loop elevated above 45 feet or so.

--
______________________
Clay Autery, KG5LKV
MONTAC Enterprises
(318) 518-1389

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thelastdb

Re: 80 Meter loop question

Clay,

I can run an EZNEC model for you if you give me some more info about the loop. You said about 45 feet high and assume square. Did you want to feed it in the middle of one side or at the corner? I will model above average ground conductivity just to keep all my analyses consistent.

I can then put the results in SimSmith and spit out all the data you'll need, complete with any transmission line and length and complex impedance including efficiency across the whole HF frequency band.

Myron WVØH
Printed on Recycled Data

> On Apr 2, 2016, at 7:45 AM, Clay Autery <[hidden email]> wrote:
>
> Does anyone have any information or a link to information data on an 80
> meter loop's complex impedance and VSWR values across the HF bands?
>
> R, X, VSWR from say 3.5-30MHz or better 1.0-54 MHz, measurements taken
> at the loop ends with a short jumper, not a long feed-line. Preferably
> with loop elevated above 45 feet or so.
>
> --
> ______________________
> Clay Autery, KG5LKV
> MONTAC Enterprises
> (318) 518-1389
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]

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Jim Brown-10

Re: 80 Meter loop question

In reply to this post by Clay Autery

On Sat,4/2/2016 6:45 AM, Clay Autery wrote:
> Does anyone have any information or a link to information data on an 80 meter loop's complex impedance and VSWR values across the HF bands?

It's pretty easy to model with NEC, which yields this data in the form a
plot of VSWR vs frequency with data points as closely spaced as you
choose. Move the cursor to each data point and you'll see complex Z.

I've learned a lot from using NEC, not only to design antennas but also
to learn from the results of the model, changing variables, etc.

4NEC2 is free and quite powerful. I use EZNEC 5.0 because I find the UI
easier to relate to, but it costs money. :)

73, Jim K9YC

73, Jim K9YC
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Mike Dodd

P3 Panadapter size

In reply to this post by Clay Autery

While eagerly awaiting delivery of my K3s kit on Tuesday, I built a
cardboard mockup of it and the P3 panadapter to see how they will fit on
my desk. <http://n4cf.mdodd.com/rig.html#NewRig>

I was surprised to discover that the screen is the same size as the one
in the PX3 I've been using with the Kx3. Plus, the front panel layout is
essentially the same as the PX3.

What's inside the P3 that justifies a cabinet 7X larger than the PX3?

I don't see any interior photos in the P3 owner's manual, and I can't
locate a P3 kit assembly manual on Elecraft's website. Does anyone have
a link to the assembly manual?

Thanks for any info.

--
73, Mike N4CF
Louisa County, VA USA
Elecraft KX3 + KXPA100 @ 100W
Elecraft PX3 panadapter
Carolina Windom up 45'
http://n4cf.mdodd.com
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Joe Subich, W4TV-4

Re: P3 Panadapter size

> What's inside the P3 that justifies a cabinet 7X larger than the PX3?

Nothing. It is made the same depth as the K3 so the front panels will
remain parallel/coplanar when both units are used with bails extended.

73,

... Joe, W4TV

On 4/2/2016 2:16 PM, Mike Dodd wrote:

> While eagerly awaiting delivery of my K3s kit on Tuesday, I built a
> cardboard mockup of it and the P3 panadapter to see how they will fit on
> my desk. <http://n4cf.mdodd.com/rig.html#NewRig>
>
> I was surprised to discover that the screen is the same size as the one
> in the PX3 I've been using with the Kx3. Plus, the front panel layout is
> essentially the same as the PX3.
>
> What's inside the P3 that justifies a cabinet 7X larger than the PX3?
>
> I don't see any interior photos in the P3 owner's manual, and I can't
> locate a P3 kit assembly manual on Elecraft's website. Does anyone have
> a link to the assembly manual?
>
> Thanks for any info.
>

Ken G Kopp

Re: P3 Panadapter size

In reply to this post by Mike Dodd

Hi Mike!

I have both the P3 and the PX3, and your question is a
natural one to ask. There's very little space inside the
P3's box that's used. I'll wager the cabinet size was
determined by the K3's cabinet. Personally, I wouldn't
want it to be any smaller, and the depth matches the
rest of the K-line. Makes "stacking" logical and convenient.

In the situation between the KX3 nd PX3 the size seems
related to the KX3.

On Sat, Apr 2, 2016 at 12:16 PM, Mike Dodd <[hidden email]> wrote:

Elecraft mailing list

Re: 80 Meter loop question

In reply to this post by Jim Brown-10

I agree, I use ver 5 also. Easier to move stuff around. Once you try modelling you will find it consumes an incredible amount of your time, but FUN.

Mel, K6KBE

From: Jim Brown <[hidden email]>
To: [hidden email]
Sent: Saturday, April 2, 2016 10:44 AM
Subject: Re: [Elecraft] 80 Meter loop question

On Sat,4/2/2016 6:45 AM, Clay Autery wrote:
> Does anyone have any information or a link to information data on an 80 meter loop's complex impedance and VSWR values across the HF bands?

It's pretty easy to model with NEC, which yields this data in the form a
plot of VSWR vs frequency with data points as closely spaced as you
choose. Move the cursor to each data point and you'll see complex Z.

I've learned a lot from using NEC, not only to design antennas but also
to learn from the results of the model, changing variables, etc.

4NEC2 is free and quite powerful. I use EZNEC 5.0 because I find the UI
easier to relate to, but it costs money. :)

73, Jim K9YC

73, Jim K9YC
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Elliott Lawrence-5

Re: P3 Panadapter size

In reply to this post by Ken G Kopp

How about room for the SVGA board and the wattmeter and other accessories that mighty use the empty connector spots on the rear panel?

Elliott WA6TLA
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john@kk9a.com

Re: 80 Meter loop question

In reply to this post by Clay Autery

Modeling is also very educational. You may learn that a proposed antenna is
inferior to a simple dipole. I agree that EZNEC is easy to use and
reasonably accurate.

John KK9A

[Elecraft] 80 Meter loop question

Mel Farrer farrerfolks at yahoo.com
Sat Apr 2 15:20:09 EDT 2016
I agree, I use ver 5 also. Easier to move stuff around. Once you try
modelling you will find it consumes an incredible amount of your time, but
FUN.

Mel, K6KBE

From: Jim Brown <jim at audiosystemsgroup.com>
To: elecraft at mailman.qth.net
Sent: Saturday, April 2, 2016 10:44 AM
Subject: Re: [Elecraft] 80 Meter loop question

On Sat,4/2/2016 6:45 AM, Clay Autery wrote:
> Does anyone have any information or a link to information data on an 80
meter loop's complex impedance and VSWR values across the HF bands?

It's pretty easy to model with NEC, which yields this data in the form a
plot of VSWR vs frequency with data points as closely spaced as you
choose. Move the cursor to each data point and you'll see complex Z.

I've learned a lot from using NEC, not only to design antennas but also
to learn from the results of the model, changing variables, etc.

4NEC2 is free and quite powerful. I use EZNEC 5.0 because I find the UI
easier to relate to, but it costs money. :)

73, Jim K9YC

______________________________________________________________
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Phil Wheeler-2

Re: P3 Panadapter size

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

Funny thing is that when I first saw the P3 I was thinking CRT due to the depth of it :-)

Of course, it's to better match the K3/K3s in depth.

73, Phil -- Sent from my iPhone 5S

> On Apr 2, 2016, at 11:33, Joe Subich, W4TV <[hidden email]> wrote:
>
>
> > What's inside the P3 that justifies a cabinet 7X larger than the PX3?
>
> Nothing. It is made the same depth as the K3 so the front panels will
> remain parallel/coplanar when both units are used with bails extended.
>
> 73,
>
> ... Joe, W4TV
>
>
>> On 4/2/2016 2:16 PM, Mike Dodd wrote:
>> While eagerly awaiting delivery of my K3s kit on Tuesday, I built a
>> cardboard mockup of it and the P3 panadapter to see how they will fit on
>> my desk. <http://n4cf.mdodd.com/rig.html#NewRig>
>>
>> I was surprised to discover that the screen is the same size as the one
>> in the PX3 I've been using with the Kx3. Plus, the front panel layout is
>> essentially the same as the PX3.
>>
>> What's inside the P3 that justifies a cabinet 7X larger than the PX3?
>>
>> I don't see any interior photos in the P3 owner's manual, and I can't
>> locate a P3 kit assembly manual on Elecraft's website. Does anyone have
>> a link to the assembly manual?
>>
>> Thanks for any info.
>

Chuck - AE4CW

Re: 80 Meter loop question

In reply to this post by Clay Autery

Clay,

I see you've received offers for data on the feed point impedance and VSWR of an 80M loop. If you feel you need more just let me know. I have modeled, built and used a number of 80M loops very successfully. Properly sized and fed, they offer well under 2:1 SWR within all the HF bands with the exception of 60M and 30M and perhaps 80M depending on the installed height. 300 ohm window line (more nearly 265 ohm) with a 4:1 balun can work very well. If you feed a square loop 80M at 1/3 the distance from any corner, the feed point impedance at resonance will be in the 200-300 ohm range...a good match for 300 (265) ohm window line and a usable match for a 4:1 balun.

Modeling is a wonderful way to experiment with the design. You can play with loop circumference and the window line and coax lengths to optimize the SWR across the bands. We use these regularly at field day and only need a tuner on 80M.
---
Chuck, AE4CW

---
Chuck, AE4CW

Bob Darlington

Re: P3 Panadapter size

In reply to this post by Mike Dodd

All that room in there or in the external speaker enclosure is perfect for
holding a GPSDO for driving the external reference board.

-Bob
N3XKB

On Sat, Apr 2, 2016 at 12:16 PM, Mike Dodd <[hidden email]> wrote:

> While eagerly awaiting delivery of my K3s kit on Tuesday, I built a
> cardboard mockup of it and the P3 panadapter to see how they will fit on my
> desk. <http://n4cf.mdodd.com/rig.html#NewRig>
>
> I was surprised to discover that the screen is the same size as the one in
> the PX3 I've been using with the Kx3. Plus, the front panel layout is
> essentially the same as the PX3.
>
> What's inside the P3 that justifies a cabinet 7X larger than the PX3?
>
> I don't see any interior photos in the P3 owner's manual, and I can't
> locate a P3 kit assembly manual on Elecraft's website. Does anyone have a
> link to the assembly manual?
>
> Thanks for any info.
>
> --
> 73, Mike N4CF
> Louisa County, VA USA
> Elecraft KX3 + KXPA100 @ 100W
> Elecraft PX3 panadapter
> Carolina Windom up 45'
> http://n4cf.mdodd.com
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]
>

Jim Brown-10

Re: 80 Meter loop question

In reply to this post by Chuck - AE4CW

On Sat,4/2/2016 2:20 PM, Chuck - AE4CW wrote:
> Properly
> sized and fed, they offer well under 2:1 SWR within all the HF bands with
> the exception of 60M and 30M and perhaps 80M depending on the installed
> height.

BUT -- remember that SWR is NOT a measure of antenna PERFORMANCE -- that
is, how strong is the signal that it radiates, and the DESIRED angles,
both vertical and horizontal. MANY antennas that have low SWR are lousy
antennas!

73, Jim K9YC
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Sverre Holm (LA3ZA)

Re: 80 Meter loop question

I've been using an 80 m horizontal loop for as long as I have had my license, about 15 years. It's a bit irregular with two supports on my house and three in trees, height is 7-12 meters. I feed it with open wire feeder to an indoor Elecraft 4:1 balun and then use the tuner of the K2 or K3 to match it to the transceiver. I've done 8-bands CW/digital DXCC, 80 - 10 m, with the loop as the work horse.

My decision at the time I put it up was very much based on the simulations that L. B. Cebik, W4RNL published. His articles are kind of hard to find on the internet now, but his best ones that I have on my hard disk are:

Horizontally Oriented, Horizontally Polarized Large Wire Loop Antennas
My Top Five Backyard Multi-Band Wire HF Antennas
Notes on All-Band Use of Horizontal-Plane Loops
Horizontal Wire Loops How Big? How High? What Shape?

These articles answer most questions on directional performance as well as impedance and SWR.

73

Sverre, LA3ZA

K2 #2198, K3 #3391,
LA3ZA Blog: http://la3za.blogspot.com,
LA3ZA Unofficial Guide to K2 modifications: http://la3za.blogspot.com/p/la3za-unofficial-guide-to-elecraft-k2.html

Clay Autery

Re: 80 Meter loop question

In reply to this post by Jim Brown-10

Thanks Jim... I've got 4NEC2, but haven't had the time to jump on that
particular learning curve.

I plan to invest in the pay version, may be EZNEC 5.0, I don't
remember. But I'm drinking from several fire hoses at the moment.
Soon, I hope...

______________________
Clay Autery, KG5LKV
MONTAC Enterprises
(318) 518-1389

On 4/2/2016 12:44 PM, Jim Brown wrote:

> On Sat,4/2/2016 6:45 AM, Clay Autery wrote:
>> Does anyone have any information or a link to information data on an
>> 80 meter loop's complex impedance and VSWR values across the HF bands?
>
> It's pretty easy to model with NEC, which yields this data in the form
> a plot of VSWR vs frequency with data points as closely spaced as you
> choose. Move the cursor to each data point and you'll see complex Z.
>
> I've learned a lot from using NEC, not only to design antennas but
> also to learn from the results of the model, changing variables, etc.
>
> 4NEC2 is free and quite powerful. I use EZNEC 5.0 because I find the
> UI easier to relate to, but it costs money. :)
>
> 73, Jim K9YC
>
> 73, Jim K9YC
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]

DC-3

Re: 80 Meter loop question

In my opinion, conditions such as soil conductivity , slope,
orientation, height, obstacles, metal structures, length of feed line
etc. vary so much it is almost worth just putting it up without getting
too deep into modeling. I definitely would model it, I modeled mine and
then just threw it up thinking it may not work a few bands. But, after
trimming it to 3.515 (my magic number, at my location), the K3 tuner can
tune it everywhere except 160 meters. Mine is a irregular triangle of
sorts with the point at 90 to 95 feet in a pine tree and the bottom
horizontal wire at about 50 feet. It is somewhere between horizontal
and vertical (the other two tree tie-offs are at about 50 feet) and fed
about 15' up one side. I run 120 feet or so (I trimmed it a couple of
times) of 450 ohm ladder line into a high power 1 to 1 current balun
outside of my shack and a 3' piece of high quality coax to my tuner.
This loop beats my 3 element Cushcraft triband at 45' on the high bands
about 80% of the time and has exceeded my expectations on 40 and 80.
Keep in mind it does not have the back or side rejection of the triband
beam on the high bands.

FWIW, I did try to orientate it so the the modeled lobes pointed in
desirable directions on the low bands. For example, one of the lobes on
40 meters should be pointed to Europe. It does work well to Europe from
the West Coast.

Richard

>>> Does anyone have any information or a link to information data on an
>>> 80 meter loop's complex impedance and VSWR values across the HF bands?

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Nr4c

Re: P3 Panadapter size

In reply to this post by Mike Dodd

It's on the web site. But the P3 is the same height and depth as the K3.

Sent from my iPhone
...nr4c. bill

> On Apr 2, 2016, at 2:16 PM, Mike Dodd <[hidden email]> wrote:
>
> While eagerly awaiting delivery of my K3s kit on Tuesday, I built a cardboard mockup of it and the P3 panadapter to see how they will fit on my desk. <http://n4cf.mdodd.com/rig.html#NewRig>
>
> I was surprised to discover that the screen is the same size as the one in the PX3 I've been using with the Kx3. Plus, the front panel layout is essentially the same as the PX3.
>
> What's inside the P3 that justifies a cabinet 7X larger than the PX3?
>
> I don't see any interior photos in the P3 owner's manual, and I can't locate a P3 kit assembly manual on Elecraft's website. Does anyone have a link to the assembly manual?
>
> Thanks for any info.
>
> --
> 73, Mike N4CF
> Louisa County, VA USA
> Elecraft KX3 + KXPA100 @ 100W
> Elecraft PX3 panadapter
> Carolina Windom up 45'
> http://n4cf.mdodd.com
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]

Ronnie Hull

Re: 80 Meter loop question

In reply to this post by DC-3

Thank you Richard! My thoughts exactly! Just pitch your loop up in the air and USE IT instead of trying to complicate it! My 75m loops is skewed all over the place, one side is lower than the other, one side sags, oh and one more thing, I've worked 289 countries with it!!

W5sum

Sent from Ronnie's IPhone

> On Apr 2, 2016, at 20:18, Richard Collier <[hidden email]> wrote:
>
> In my opinion, conditions such as soil conductivity , slope, orientation, height, obstacles, metal structures, length of feed line etc. vary so much it is almost worth just putting it up without getting too deep into modeling. I definitely would model it, I modeled mine and then just threw it up thinking it may not work a few bands. But, after trimming it to 3.515 (my magic number, at my location), the K3 tuner can tune it everywhere except 160 meters. Mine is a irregular triangle of sorts with the point at 90 to 95 feet in a pine tree and the bottom horizontal wire at about 50 feet. It is somewhere between horizontal and vertical (the other two tree tie-offs are at about 50 feet) and fed about 15' up one side. I run 120 feet or so (I trimmed it a couple of times) of 450 ohm ladder line into a high power 1 to 1 current balun outside of my shack and a 3' piece of high quality coax to my tuner. This loop beats my 3 element Cushcraft triband at 45' on the high bands ab
out 80% of the time and has exceeded my expectations on 40 and 80. Keep in mind it does not have the back or side rejection of the triband beam on the high bands.

>
> FWIW, I did try to orientate it so the the modeled lobes pointed in desirable directions on the low bands. For example, one of the lobes on 40 meters should be pointed to Europe. It does work well to Europe from the West Coast.
>
> Richard
>
>>>> Does anyone have any information or a link to information data on an
>>>> 80 meter loop's complex impedance and VSWR values across the HF bands?
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]

Wes Stewart-2

Re: 80 Meter loop question

In reply to this post by Elecraft mailing list

If you're not using Dan's (AC6LA) AutoEZ program as a front end to Eznec, you
don't know what you're missing.

On 4/2/2016 12:20 PM, Mel Farrer via Elecraft wrote:

> I agree, I use ver 5 also. Easier to move stuff around. Once you try modelling you will find it consumes an incredible amount of your time, but FUN.
>
> Mel, K6KBE
>
>
> From: Jim Brown <[hidden email]>
> To: [hidden email]
> Sent: Saturday, April 2, 2016 10:44 AM
> Subject: Re: [Elecraft] 80 Meter loop question
>
> On Sat,4/2/2016 6:45 AM, Clay Autery wrote:
>> Does anyone have any information or a link to information data on an 80 meter loop's complex impedance and VSWR values across the HF bands?
> It's pretty easy to model with NEC, which yields this data in the form a
> plot of VSWR vs frequency with data points as closely spaced as you
> choose. Move the cursor to each data point and you'll see complex Z.
>
> I've learned a lot from using NEC, not only to design antennas but also
> to learn from the results of the model, changing variables, etc.
>
> 4NEC2 is free and quite powerful. I use EZNEC 5.0 because I find the UI
> easier to relate to, but it costs money. :)
>
> 73, Jim K9YC
>
> 73, Jim K9YC
>