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The simplest book which covers the proper subjects with as little calculus
as I've seen is:

Surprisingly enough, MFJ has an excellent resource. I picked up a copy at
HRO a couple of years ago, well before the COVID thing. It's a bit terse
in treatments, but its pretty good:

*ANTENNAS AND TRANSMISSION LINES* by John A. Kuecken, Published: MFJ,
First edition, 2nd printing ......... no ISBN number

While one can hardly treat the subject without a little calculus, he has
kept it to a minimum. However, a solid and working knowledge of algebra
and trigonometry is required.

If you ae looking for a reference with absolutely no calculus and still
treats the necessary subjects properly, your out of luck. The book
published by MFJ is about as close to that as I've come across and is still
responsible to engineering and physics. Even the J. D. Kraus *ANTENNAS*
requires calculus. Without that math tool, you're up a creek as E&M
requires calculus. Try the MJF book. I believe it's the best on the
present market with minimal math.

Or take the plunge and learn a bit of good solid math. Life-long learning
is golden, especially in retirement.

Dave - W?LEV

--
*Dave - W?LEV*
*Just Let Darwin Work*

On 2/2/2021 3:18 PM, Jim Lux wrote:

On 2/2/21 10:17 AM, David Eckhardt wrote:

oooops.? When I send them to the files section, I shall do so.??? Thanks
for the suggestion.? I thought Apple could read .docx files. Are we back
to Apple vs. IBM?? Humbug......

I suspect it's MS Word vs something else.

docx works just fine on Mac OS, but you need MS Word.

Open Office works good with docx files.? Gave up on Microsoft stuff when they went to a subscriber model.

Eric WA3UYI

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This email has been checked for viruses by Avast antivirus software.

On 2/2/21 10:17 AM, David Eckhardt wrote:

oooops. When I send them to the files section, I shall do so. Thanks
for the suggestion. I thought Apple could read .docx files. Are we back
to Apple vs. IBM? Humbug......

I suspect it's MS Word vs something else.

.docx works just fine on Mac OS, but you need MS Word.

Dave

On Tue, Feb 2, 2021 at 6:15 PM Joe St. Clair AF5MH <saintc@...>
wrote:

I suggest that you convert the document to PDF format. The .docx format
seems to be problematic on non-Microsoft systems.

Having not seen or read that book, I can’t say. Perhaps someone else on the list can answer that.

DaveD

On Mon, Feb 1, 2021 at 10:21 AM, Dave Daniel wrote:

Does something like the Practical Antenna Handbook by Carr and Hippisley provide a good overview of antennas for a ham without a background in calculus? I can't exactly undertake a graduate-level study of the topic at the moment, haha.

There are many textbooks out there. Some are:

Any revision of John Kraus’ “Antennas” text (classic and probably the best choice when starting out)

Any revision of Balanis’ “Antenna Theory” text

Weeks’ “Antenna Engineering” (another good entry-level text)

Collin “Antennas and Microwave Propagation”

Collin and Zucker “Antenna Theory” (2 volume set)

Elliot “Antenna Theory and Design”

Lee “Vertical Antenna Handbook”

RSGB “Antennas for all Locations”

Shelkunoff of early Bell Labs fame also wrote several texts on antennas, at least one of which is advanced.

Realize that most of the above are engineering textbooks and thus are mathematically-based. Some are quite old. I would use bookfinder.com and search using the author’s name and “antenna” in the title field.

DaveD

On Feb 1, 2021, at 10:27, Cierra dubosec@... wrote:

Other than the ARRL Antenna Book, are there good resources to investigate to learn more about these topics?

I have not done so but certainly can. I take the practical approach that
it's what the system presents to the input of the L-network matching
network with the CMC between the feeder and the network input. Do I really
care what the feedpoint looks like? Yes, from a modelling and total system
characterization, I do, but from a strictly practical viewpoint, it doesn't
matter.

Dave - W?LEV

--
*Dave - W?LEV*
*Just Let Darwin Work*

And Unix and Android I think.

David:

And if you “subtract” effect of your X feet of feed using your analyzer (or Zplots or whatever) out of curiosity what are the impedances at your same various frequencies at the feedpoint of the 450 foot doublet?

Any conclusions from a comparison?


Ed McCann
AG6CX

Attachments were lost in the forward.


On Tue, 2 Feb 2021 at 18:41, Dragan Milivojevic via groups.io
<d.milivojevic@...> wrote:

On Tue, 2 Feb 2021 at 18:37, Dragan Milivojevi? <d.milivojevic@...>
wrote:

It's a SimSmith graph, I have attached the circuit and the S file that

was

used:

[image: image.png]





On Tue, 2 Feb 2021 at 18:25, David Eckhardt <davearea51a@...>

wrote:

Dragan:

I have not seen a way to plot the second chart. Please let me know and
I'll take a look at my chokes in that respect. The dotted lavender

line in

the second plot looks like series resonance somewhere near 7.5 MHz.

Dave - W?LEV

Be careful not to apply too much pressure when tightening the N Connector as it not securely fastened. The N Connector is soldered to the internal SMA. I ASSumed when I looked at mine that the N Connector was held in place to the metal chassis but it's not, only has the one nut on outside holding the plate in. You can add a thinner nut to the inside which will make the connector more secure.

oooops. When I send them to the files section, I shall do so. Thanks
for the suggestion. I thought Apple could read .docx files. Are we back
to Apple vs. IBM? Humbug......

Dave

On Tue, Feb 2, 2021 at 6:15 PM Joe St. Clair AF5MH <saintc@...>
wrote:

I suggest that you convert the document to PDF format. The .docx format
seems to be problematic on non-Microsoft systems.

--
*Dave - W?LEV*
*Just Let Darwin Work*

I suggest that you convert the document to PDF format. The .docx format seems to be problematic on non-Microsoft systems.

John:

1 SAVER- what is this, where do you get it, how do you use it?....reference
essential
NANOVNA SAVER is a SW application that runs on a PC or laptop. It was done
by the same folks who did the NANOs. It is free and downloadable at:


2. Stand-alone Procedure needed.
I can work on that if I receive other requests for that option. Once you
use SAVER, I believe you will want to use it as there are more options and
a large screen to work with.

3 Test fixture, which looks ok for HF, could have significant stray
coupling for use at v/uhf- a VHF CMC is the first project here. A plot of
the test fixture open cct coupling /loss up to the freq. limit of the vna
would be helpful. Converting everything to BNC is a GOOD idea.
I use BNCs for everything ≤ 100 watts. However, above 70-cm, I generally
use SMA connectors. The fixture I built is not appropriate for anything
much above 50 MHz. On occasion, I cal it up to 200 MHz, but that is a real
stretch and the data is not too reliable, requiring 'sanity checks' of
known standards. On an open after cal from 1 MHz through 30 MHz, it
measured into the megohms. If you really want to extend the frequency
coverage of the fixture, an entirely different design is required. I'd
suggest building a fixture using double-sided FR-4 board 0.625-inches or
160-cm thickness and cutting microstripline to/from SMA connectors at
either end of the line. The stripline width on that material for 50-ohms
Zo is roughly 0.125-inches or 0.318 cm. Leave an open gap in the center
of the line to connect (solder) your DUT (Device Under Test). Building a
reliable fixture can be done, but it is not trivial.

4 If you cite previous measurements, you should reference where they are,
or include them
I'll attach them to this post.

5 USA specific antenna wire types - not helpful to a world-wide audience,
again, reference desirable.
So far, the 'antenna' wire from DavisRF which I have sited is the most
successful for these CMCs. I wound one core with PVC insulation from Ace
Hardware. The insulation heated badly with any real power and I watched
the SWR climb on key-down at 400-watts. Not appropriate for this
application. Today I should have delivered a length of AWG #12 stranded
and Teflon insulated wire to further explore that option. The thickness of
the insulation indicates it should take as a minimum up to 20 kV so I
should not have the problem I had with arcing and coronal discharges with
the AWG #12 enameled conductor. A handy conversion chart between metric
cross section and AWG sizing can be accessed at:


I don't buy off on the 'king's foot' either. The US tried forcing
conversion to metric, but the house wives, civil engineers, . . . . . spit
it right back. Personally, I prefer metric, but I live in the world of the
'king's foot'.

6 I'm a little surprised that both wires at each end of the CMC are not
connected.
I knew I'd get this question. I've tried connecting both and the
difference is minor. Once you have things set up, try comparing single
winding vs. both in parallel. There is really very little difference which
does not justify further complication (I have 'shorting' banana plugs for
the purpose).

Dave - W?LEV

On Tue, Feb 2, 2021 at 12:17 PM John Button G8JMB via groups.io
<hornpipe112@...> wrote:

Hi Dave

Thanks for the procedure;Exactly what I want to do. It's generally clear
but as a 'new driver' of the VNA in my Santa sack, I have a couple of
comments / requests
1 SAVER- what is this, where do you get it, how do you use
it?....reference essential
2. Stand-alone Procedure needed.
3 Test fixture, which looks ok for HF, could have significant stray
coupling for use at v/uhf- a VHF CMC is the first project here. A plot of
the test fixture open cct coupling /loss up to the freq. limit of the vna
would be helpful. Converting everything to BNC is a GOOD idea.
4 If you cite previous measurements, you should reference where they are,
or include them
5 USA specific antenna wire types - not helpful to a world-wide audience,
again, reference desirable.
6 I'm a little surprised that both wires at each end of the CMC are not
connected.

73
Keep up the good work

John G8JMB

--
*Dave - W?LEV*
*Just Let Darwin Work*

@brown.beard.2020:

A ferrite core may stop noise and interference leaking?into the cable, but not that picked by the antenna itself (which will likely be your biggest problem). For this you'll need an actual bandpass filter, which is not hard to do at 13.5 MHz if you have access to a soldering iron and some hand tools.
First you need a design, which I already did for you using one of the many available online tools:

You connect one side to the antenna and the other to the device. You can buy the components from online retailers such as Newark, Digi-Key or Mouser?for about $10. To build the filter you don't need a PCB; you can simply use a strip of copper or tin, and solder the components using the dead bug construction technique. You can even use an Altoids tin, which also gives you an enclosure. The lower continuous wire in the diagram represents the copper strip or tin box, which is your "ground plane".
Maybe not as simple as a ferrite core but definitely more effective.

On Tue, 2 Feb 2021 at 18:37, Dragan Milivojevi? <d.milivojevic@...>
wrote:

It's a SimSmith graph, I have attached the circuit and the S file that was
used:

[image: image.png]





On Tue, 2 Feb 2021 at 18:25, David Eckhardt <davearea51a@...> wrote:

Dragan:

I have not seen a way to plot the second chart. Please let me know and
I'll take a look at my chokes in that respect. The dotted lavender line in
the second plot looks like series resonance somewhere near 7.5 MHz.

Dave - W?LEV

JOHN,
I have the same issue with metric-only BOMs from Europe. Cross-referencing 0.4mm wire to what we have here in US AWG.
Gary
W9TD

On 2/2/21 5:04 AM, brown.beard.2020@... wrote:

Hi All

Sorry if this is not the right place to ask. Feel free to point me to a more suitable place for my questions.

I have an antenna connected to a 13.56MHz RF signal and would like to add a ferrite core to the cable from the antenna to the device to filter out any noise coming from the environment.
How do i determine the appropriate specs for the ferrite core?

That's the ISM frequencies just below the amateur radio 20 meter band, so anything that works for 14 MHz (20m) will probably work just fine for 13.56 MHz.

In general, 31 mix is a good choice for HF - it's suitably lossy at those frequencies.? You might check out K9YC's choke cookbooks and other writeups..



You're presumably at low power for something like a badge reader, so you probably aren't as interested in low loss transmitter designs.




*RFI, Ferrites, and Common Mode Chokes For Hams <>**Most recent update April 2019.*This tutorial is directed specifically to RFI in ham radio applications. It includes an extended discussion of the use of common mode chokes in antenna systems and for suppression of RFI. A chapter on audio and computer interconnections in ham stations shows how to make bulletproof connections between a computer sound card and ham rigs for SSB, RTTY, PSK31, and SO2R contesting without expensive interface boxes, using nothing more than simple cables with the right connectors on each end. There's also a chapter on grounding and bonding.


This is a new applications note summarizing my work on *Chokes and Transformers For Receiving Antennas. <>**NEW!*October 2018

Try the ham-antennas group.

DaveD

Hi All

Sorry if this is not the right place to ask. Feel free to point me to a more suitable place for my questions.

I have an antenna connected to a 13.56MHz RF signal and would like to add a ferrite core to the cable from the antenna to the device to filter out any noise coming from the environment.
How do i determine the appropriate specs for the ferrite core?

Thanks

They are all true. :-)

Zack W9SZ

On Sun, Jan 31, 2021 at 9:48 PM Cierra <dubosec@...> wrote:

This might be a dumb question, but where are the answers listed?

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