Topband: Measuring Vertical input parameters while installing radials
KB8NTY
kb8nty at wowway.com
Sat Sep 21 20:04:04 EDT 2013
Eddie,
Great Job!
I would not worry to take results any further unless an individual request.
Your results are a helpful visual, resulting in the fact that indeed you can
obtain increased DB's as a result of simple RF ground radials!
Those who re-quote the statement that a "vertical antenna radiates equally
poor in all directions" need to learn about ground radials...
The subject has been worked & re-worked by many in years past, with varied
results by those who have investigated.
N6LF - Rudy comes to mind with his very detailed study.
To keep it simple & allow the hobby to remain enjoyable-your results should
speak volumes.
Adding radials equal increased efficiency.
I have a filtered RF ground radial link available below, which should offer
those who may have interest in RF ground radials, hours & hours of good
interesting reading.
http://www.rossradio.net/
Thank you Eddie for your contribution!
-73- KB8NTY
http://www.rossradio.net/
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
----- Original Message -----
From: <topband-request at contesting.com>
To: <topband at contesting.com>
Sent: Friday, September 20, 2013 12:00 PM
Subject: Topband Digest, Vol 129, Issue 29
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> Today's Topics:
>
> 1. Re: Hairpin Matching Coil Questions - "Shunt"? (Jim GM)
> 2. 'Hairpin' matching (Tom Boucher)
> 3. Re: Hairpin Matching Coil Questions - "Shunt"? (Tom W8JI)
> 4. 'Hairpin' matching (Tom Boucher)
> 5. AutoEZ v2 with Optimizer (Dan Maguire)
> 6. Re: 'Hairpin' matching (Charlie Cunningham)
> 7. Re: Measuring Vertical input parameters while installing
> radials (Eduardo Araujo)
> 8. Re: AutoEZ v2 with Optimizer (Charlie Cunningham)
> 9. Re: 'Hairpin' matching (John Chappell G3XRJ)
> 10. Re: Measuring Vertical input parameters while installing
> radials (Charlie Cunningham)
> 11. Re: elevated radials (Mike Waters)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Thu, 19 Sep 2013 13:25:02 -0500
> From: Jim GM <jim.gmforum at gmail.com>
> To: topband <topband at contesting.com>
> Subject: Re: Topband: Hairpin Matching Coil Questions - "Shunt"?
> Message-ID:
> <CAD+2Gyv-O=LHuK6fNhwmERocfAJKc+ZGXNSkWZvQ+yLaqPB4Zg at mail.gmail.com>
> Content-Type: text/plain; charset=ISO-8859-1
>
> Thankyou Charlie.
>
> I got those Q numbers from
> http://www.m0ukd.com/Calculators/air_core_inductor_calculator/
> Maybe a decimal point was left out.
>
> Thanks Tom
>
> --
> Jim K9TF
>
>
> ------------------------------
>
> Message: 2
> Date: Thu, 19 Sep 2013 19:52:33 +0100
> From: "Tom Boucher" <tom at telemetry.demon.co.uk>
> To: "160 reflector" <topband at contesting.com>
> Subject: Topband: 'Hairpin' matching
> Message-ID: <B5E21A6FDAC14C5CB33D4039811252CC at Tom>
> Content-Type: text/plain; charset="iso-8859-1"
>
> Just to add a comment on this thread:
>
> I do not use an inductor to match my inverted 'L', just a capacitor from
> coax centre/bottom of wire to the radial point. Further I do not use big
> wide space 'toast-rack' Cs, but tiny ceramic ones rated at 6.3KV which
> will handle very decent amounts of power and are readily available over
> here. They seem to handle the high currents at the bottom of the quarter
> wave 'L' quite happily.
>
> I measure the impedance at resonance of the antenna without any matching
> network, then use
> www.sandiego.edu/~ekim/e194rfs01/jwmatcher2.html
>
> to calculate the L-network values needed. Fit the parallel capacitor then
> lengthen the antenna slightly to bring it back to the required frequency.
> This provides the inductance necessary for the L-network.
>
>
>
> Needless to say, your MFJ, or Palstar ZM-30 in my case, antenna analyser
> will probably give you the wrong sign for the reactive part of the
> antenna's impedance. This had me going for a long time before I realised
> the problem! Check this by moving the analyser frequency LF from resonance
> and the impedance should show -jX (capacitive). Moving the analyser HF
> from resonance should show inductive reactance (+jX).
>
>
>
> My inverted 'L' needs 1600pF to give me 50 + j0.
>
>
>
> I have also made switched L-networks to successfully resonate the same
> antenna on some other bands.
>
>
>
> 73
>
> Tom G3OLB
>
>
> ------------------------------
>
> Message: 3
> Date: Thu, 19 Sep 2013 16:22:57 -0400
> From: "Tom W8JI" <w8ji at w8ji.com>
> To: "Jim GM" <jim.gmforum at gmail.com>, "topband"
> <topband at contesting.com>
> Subject: Re: Topband: Hairpin Matching Coil Questions - "Shunt"?
> Message-ID: <3F7B5C34343645EF9DDACB0DCBFC62E3 at MAIN>
> Content-Type: text/plain; format=flowed; charset="iso-8859-1";
> reply-type=original
>
>> Thankyou Charlie.
>>
>> I got those Q numbers from
>> http://www.m0ukd.com/Calculators/air_core_inductor_calculator/
>> Maybe a decimal point was left out.
>
> Jim,
>
> I thought something was misleading you somewhere.
>
>
> Be careful with online calculators. The one in the link uses pi out to 39
> places (which might give the impression of accuracy), but omits many far
> more critical, important, parameters. It is a very rough guess that might
> be
> a mile off, even though the publisher implies accuracy. They would be
> better
> off to just use "3.1" for Pi, and add in some more important things.
>
> One way to evaluate an inductor calculator for design omissions is to see
> if
> it asks for:
>
> 1.) Insulation thickness and type
> 2.) Turns spacing
> 3.) Form material
> 4.) Conductor size
> 5.) Form length
> 6.) Form diameter
>
> That one grossly fails. It doesn't ask for several important things.
>
>
> To check the calculator for function, start taking a large coil up higher
> in
> frequency. If you get weird results like progressively increasing Q that
> goes over 1000 for normal good conductors, extreme inductance values (like
> values near whole Henries at HF and higher), the calculator is likely just
> junk.
>
> That one completely fails. It obviously does not consider turn-to-turn
> capacitance, skin effect, materials, or internal resonances, because I can
> "make" door bell wire inductors with Q's in the thousands and almost a
> Henry
> of inductance on 50 MHz!!
>
> Since it doesn't ask for enough things and obviously ignores many
> important
> traits of inductors, it is unreliable. It might work in some cases by pure
> luck, but who knows when it could be trusted!!
>
> Things like that can send you down the wrong path, and cause you to start
> giving out wrong numbers.
>
> 73 Tom
>
>
>
> ------------------------------
>
> Message: 4
> Date: Fri, 20 Sep 2013 07:25:18 +0100
> From: "Tom Boucher" <tom at telemetry.demon.co.uk>
> To: "160 reflector" <topband at contesting.com>
> Subject: Topband: 'Hairpin' matching
> Message-ID: <B2F6B0749DD74038A2250A2A0D97A705 at Tom>
> Content-Type: text/plain; charset="iso-8859-1"
>
> The excellent web site for calculating matching network values should have
> been:
>
> http://home.sandiego.edu/~ekim/e194rfs01/jwmatcher/matcher2.html
>
> not the one I posted yesterday.
>
> 73,
> Tom G3OLB
>
>
>
> ------------------------------
>
> Message: 5
> Date: Fri, 20 Sep 2013 01:48:17 -0700 (PDT)
> From: Dan Maguire <djm2150 at yahoo.com>
> To: topband at contesting.com
> Subject: Topband: AutoEZ v2 with Optimizer
> Message-ID:
> <1379666897.77410.YahooMailBasic at web125405.mail.ne1.yahoo.com>
> Content-Type: text/plain; charset=us-ascii
>
> AutoEZ is an Excel application that lets you automate the use of EZNEC.
> Version 2 is now available. Major changes are 1) an optimizer, 2) new
> "Create" dialog windows to easily build common antenna configurations, and
> 3) faster calculation speeds.
>
> The AutoEZ home page with revised documentation is here:
> http://ac6la.com/autoez.html
>
> For a complete list of all changes since v1 see:
> http://ac6la.com/aenewforv2.html
>
> A free demo version of AutoEZ is available for download. The demo
> includes the optimizer feature.
>
> Dan, AC6LA
>
>
> ------------------------------
>
> Message: 6
> Date: Fri, 20 Sep 2013 08:15:51 -0400
> From: "Charlie Cunningham" <charlie-cunningham at nc.rr.com>
> To: "'Tom Boucher'" <tom at telemetry.demon.co.uk>, "'160 reflector'"
> <topband at contesting.com>
> Subject: Re: Topband: 'Hairpin' matching
> Message-ID:
> <!&!AAAAAAAAAAAYAAAAAAAAAF0xXac1rOhFkn7GlcEWNIjCgAAAEAAAACgK5fVIF41BlN+usQG1Cv4BAAAAAA==@nc.rr.com>
>
> Content-Type: text/plain; charset="us-ascii"
>
> Very nice to have all of those collected into one place!
>
> Thanks for sharing, Tom! Have a god day!
>
> 73,
> Charlie, K4OTV
>
> -----Original Message-----
> From: Topband [mailto:topband-bounces at contesting.com] On Behalf Of Tom
> Boucher
> Sent: Friday, September 20, 2013 2:25 AM
> To: 160 reflector
> Subject: Topband: 'Hairpin' matching
>
> The excellent web site for calculating matching network values should have
> been:
>
> http://home.sandiego.edu/~ekim/e194rfs01/jwmatcher/matcher2.html
>
> not the one I posted yesterday.
>
> 73,
> Tom G3OLB
>
> _________________
> Topband Reflector
>
>
>
> ------------------------------
>
> Message: 7
> Date: Fri, 20 Sep 2013 05:31:47 -0700 (PDT)
> From: Eduardo Araujo <er_araujo at yahoo.com>
> To: Topband <topband at contesting.com>
> Subject: Re: Topband: Measuring Vertical input parameters while
> installing radials
> Message-ID:
> <1379680307.68664.YahooMailNeo at web160703.mail.bf1.yahoo.com>
> Content-Type: text/plain; charset=iso-8859-1
>
> Hi friends,
> ??????????????? I finished sending the measurements data to all that
> requested it. In case somebody didn?t receive it yet, please let me know.
>
> Even though I did not mention it before, I also have Field Strength
> measurement synchronized in time with the AIM measurements.
>
> As surely this was not a professional procedure, I will explain how I did
> it and you may judge if it is useful for you or not.
>
> - I installed 2 verticals antennas 3 mts long, at about 300-350 meters
> from the tower base in two opposite directions. So measurement was done at
> ground level.
> - I did not tuned up the elements in any way, they were connected to the
> FS instrument directly and as ground connection I used a 50 cm aluminum
> pipe buried in the ground
>
> - As a FS meter I used a DIGI - FIELD from IC- Engineering
>
> - First 2 radials were installed more or less in the direction of the RX
> verticals
> - From there, they were installed consecutive in counter-clock wise. (look
> from above)
> - I used 20W at 1840 during daylight, and matched the antenna input for
> every change in radial number. I used an MFJ-962B for this purpose.
> - After all readings were done, I calibrate the readings against an
> HP-8640B signal to visualize which was the change in db
>
> Botton line - the measured change at ground level between 2 and 114
> radials was between 5.2 in one direction and 5.8 db to the other.
>
> I understand this is not a professional procedure nor professional
> equipment and it was done having fun enjoying the hobby.
>
> I will like to hear from you your thought about if this kind of
> measurement done at ground level and at that distance from the antenna
> base has a correlation to actual radiated Field at the maximum vertical
> azimuth of the vertical whichever it is.
> And, also, How the procedure or elements I used could be improved
> ....still within amateur measurement accuracy and not professional level.
>
>
> '73 to all..... Eddie, LU2DKT
>
>
>
>
>
> ----------------------------------------------------------------------------------------------------------------
>
> From: Eduardo Araujo <er_araujo at yahoo.com>
>
> To: Topband <topband at contesting.com>
> Sent: Thursday, September 12, 2013 9:28 AM
> Subject: Measuring Vertical input parameters while installing radials
>
>
>
> Hi everyone, I recently complete the installation of +100 1/4 radials for
> the 1/4 vertical.
>
> I measured input vertical parameters using AIM4170 from 1600 to 2000Kc
>
> I assumed it is not something new for many of you, but I wonder if the
> information I collected may be of interest for some of the group members.
>
> I have available for sharing BMP or JPG images of each scan which were run
> at 2, 4, 8, 16, 32, 60 and +110 radials. Also, I have the .scn files for
> each scan which could be viewed using AIM4170 SW even though you don?t
> have the unit.
>
>
> The good thing looking at the files using the sw is that you can move the
> cursor and have all the values at all fcies from 1600-2000 Kc
>
> In case someone is interested, let me know and I will see the way to share
> it.
>
> ?73 to everyone.... Eddie, LU2DKT
>
> PS: By the way, what a nice toy the AIM !!!, Even though I bought it more
> than one year ago, this is the first time I use it
>
> ------------------------------
>
> Message: 8
> Date: Fri, 20 Sep 2013 08:38:44 -0400
> From: "Charlie Cunningham" <charlie-cunningham at nc.rr.com>
> To: "'Dan Maguire'" <djm2150 at yahoo.com>, <topband at contesting.com>
> Subject: Re: Topband: AutoEZ v2 with Optimizer
> Message-ID:
> <!&!AAAAAAAAAAAYAAAAAAAAAF0xXac1rOhFkn7GlcEWNIjCgAAAEAAAADW4NUZikEVNrR4r+1pbfH4BAAAAAA==@nc.rr.com>
>
> Content-Type: text/plain; charset="us-ascii"
>
>
> Thanks for sharing, Dan! I've used EZNEC a LOT over the years, and I've
> done
> a lot of useful work with it, but I was unaware of AutoEZ. I'll look into
> it
> and maybe investigate the paid version as well.
>
> Thanks, and have a good day!
>
> 73,
> Charlie, K4OTV
>
>
> -----Original Message-----
> From: Topband [mailto:topband-bounces at contesting.com] On Behalf Of Dan
> Maguire
> Sent: Friday, September 20, 2013 4:48 AM
> To: topband at contesting.com
> Subject: Topband: AutoEZ v2 with Optimizer
>
> AutoEZ is an Excel application that lets you automate the use of EZNEC.
> Version 2 is now available. Major changes are 1) an optimizer, 2) new
> "Create" dialog windows to easily build common antenna configurations, and
> 3) faster calculation speeds.
>
> The AutoEZ home page with revised documentation is here:
> http://ac6la.com/autoez.html
>
> For a complete list of all changes since v1 see:
> http://ac6la.com/aenewforv2.html
>
> A free demo version of AutoEZ is available for download. The demo
> includes
> the optimizer feature.
>
> Dan, AC6LA
> _________________
> Topband Reflector
>
>
>
> ------------------------------
>
> Message: 9
> Date: Fri, 20 Sep 2013 15:05:25 +0100
> From: John Chappell G3XRJ <john at g3xrj.com>
> To: topband at contesting.com
> Subject: Re: Topband: 'Hairpin' matching
> Message-ID: <523C5625.7070905 at g3xrj.com>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> Just measured the 'hairpin' coil for my 160m 38 foot top loaded - coil
> and 2 x 18 foot wires - antenna.
>
> Feedpoint impedance without match is 12 ohms.
> Placing shunt coil to ground of 1.7microH and tx sees 50 ohm 1:1.
>
> Only problem with the vertical being so short the bandwidth is only 12
> khz between 2:1 points.
>
> John G3XRJ
>
>
>> The excellent web site for calculating matching network values should
>> have been:
>>
>> http://home.sandiego.edu/~ekim/e194rfs01/jwmatcher/matcher2.html
>>
>> not the one I posted yesterday.
>>
>> 73,
>> Tom G3OLB
>>
>> _________________
>> Topband Reflector
>>
>
>
>
> ------------------------------
>
> Message: 10
> Date: Fri, 20 Sep 2013 10:10:33 -0400
> From: "Charlie Cunningham" <charlie-cunningham at nc.rr.com>
> To: "'Eduardo Araujo'" <er_araujo at yahoo.com>, "'Topband'"
> <topband at contesting.com>
> Subject: Re: Topband: Measuring Vertical input parameters while
> installing radials
> Message-ID:
> <!&!AAAAAAAAAAAYAAAAAAAAAF0xXac1rOhFkn7GlcEWNIjCgAAAEAAAAEGDM6c6gmhMhtQKwGvBo8IBAAAAAA==@nc.rr.com>
>
> Content-Type: text/plain; charset="iso-8859-1"
>
> Hi, Eddie
>
> Nicely done! Looks reasonably professional to me! At the very least,
> you've made a good effort to quantify your results in a meaningful and
> repeatable way, with decent tools. No need to tune your sense antennas,
> as
> long as there is enough signal level and dynamic range for your FS
> measurements.
>
> Congrats on having mad some meaningful quantitative measurements! Thanks
> for
> sharing!
>
> 73,
> Charlie, K4OTV
>
> -----Original Message-----
> From: Topband [mailto:topband-bounces at contesting.com] On Behalf Of Eduardo
> Araujo
> Sent: Friday, September 20, 2013 8:32 AM
> To: Topband
> Subject: Re: Topband: Measuring Vertical input parameters while installing
> radials
>
> Hi friends,
> ??????????????? I finished sending the measurements data to all that
> requested it. In case somebody didn?t receive it yet, please let me know.
>
> Even though I did not mention it before, I also have Field Strength
> measurement synchronized in time with the AIM measurements.
>
> As surely this was not a professional procedure, I will explain how I did
> it
> and you may judge if it is useful for you or not.
>
> - I installed 2 verticals antennas 3 mts long, at about 300-350 meters
> from
> the tower base in two opposite directions. So measurement was done at
> ground
> level.
> - I did not tuned up the elements in any way, they were connected to the
> FS
> instrument directly and as ground connection I used a 50 cm aluminum pipe
> buried in the ground
>
> - As a FS meter I used a DIGI - FIELD from IC- Engineering
>
> - First 2 radials were installed more or less in the direction of the RX
> verticals
> - From there, they were installed consecutive in counter-clock wise. (look
> from above)
> - I used 20W at 1840 during daylight, and matched the antenna input for
> every change in radial number. I used an MFJ-962B for this purpose.
> - After all readings were done, I calibrate the readings against an
> HP-8640B
> signal to visualize which was the change in db
>
> Botton line - the measured change at ground level between 2 and 114
> radials
> was between 5.2 in one direction and 5.8 db to the other.
>
> I understand this is not a professional procedure nor professional
> equipment
> and it was done having fun enjoying the hobby.
>
> I will like to hear from you your thought about if this kind of
> measurement
> done at ground level and at that distance from the antenna base has a
> correlation to actual radiated Field at the maximum vertical azimuth of
> the
> vertical whichever it is.
> And, also, How the procedure or elements I used could be improved
> ....still
> within amateur measurement accuracy and not professional level.
>
>
> '73 to all..... Eddie, LU2DKT
>
>
>
>
>
> ----------------------------------------------------------------------------
> ------------------------------------
>
> From: Eduardo Araujo <er_araujo at yahoo.com>
>
> To: Topband <topband at contesting.com>
> Sent: Thursday, September 12, 2013 9:28 AM
> Subject: Measuring Vertical input parameters while installing radials
>
>
>
> Hi everyone, I recently complete the installation of +100 1/4 radials for
> the 1/4 vertical.
>
> I measured input vertical parameters using AIM4170 from 1600 to 2000Kc
>
> I assumed it is not something new for many of you, but I wonder if the
> information I collected may be of interest for some of the group members.
>
> I have available for sharing BMP or JPG images of each scan which were run
> at 2, 4, 8, 16, 32, 60 and +110 radials. Also, I have the .scn files for
> each scan which could be viewed using AIM4170 SW even though you don?t
> have
> the unit.
>
>
> The good thing looking at the files using the sw is that you can move the
> cursor and have all the values at all fcies from 1600-2000 Kc
>
> In case someone is interested, let me know and I will see the way to share
> it.
>
> ?73 to everyone.... Eddie, LU2DKT
>
> PS: By the way, what a nice toy the AIM !!!, Even though I bought it more
> than one year ago, this is the first time I use it
> _________________
> Topband Reflector
>
>
>
> ------------------------------
>
> Message: 11
> Date: Fri, 20 Sep 2013 10:42:16 -0500
> From: Mike Waters <mikewate at gmail.com>
> To: topband <topband at contesting.com>
> Subject: Re: Topband: elevated radials
> Message-ID:
> <CA+FxYXgOdihGKak1B4CwNZj7nN93YXnX9OYyUfKVBa7q0kODiw at mail.gmail.com>
> Content-Type: text/plain; charset=ISO-8859-1
>
> Hello Jim,
>
> Thank you for this. I don't doubt for a second that my elevated 1/4 wave
> radial currents may be unequal. I should throw together an RF current
> meter
> and check them sometime, and add more radials while I'm at it. After the
> ticks and chiggers here die, though. :-)
>
> I don't have any Communications Quarterly issues, but K5IU's article
> sounds
> interesting, if anyone has a copy.
>
> 73, Mike
> www.w0btu.com
>
> **
>> Hey Mike
>>
>> Saw your post to TB reflector:
>>
>> "I suppose if you made the elevated radials long, then you could adjust
>> the current balance with series variable capacitors. You could use a
>> simple
>> clamp-on meter like W8JI has on his site to measure the relative current,
>> perhaps.I didn't bother with that myself, I was just careful to keep the
>> radial lengths the same length and height."
>>
>> My old friend K5IU had an article "Optimum Elevated Radial Vertical
>> Antennas" in Communication Quarterly, Spring 1997, pp 9 - 27. He showed
>> why 1/4 wave elevated radials are the worst length as it invariably
>> results
>> in radials having unequal currents (at least on the low bands where the
>> height is small in terms of lambda). He only concluded the pattern was
>> distorted, explicitly stating no opinion on efficiency. Dick is pretty
>> careful - he likes actual measurements. The fix was to use non-1/4 wave
>> radials with a single lumped reactance between the shield and the
>> junction
>> of all the radials to bring to resonance. Using separate reactors for
>> each
>> radial makes it too critical to adjust.
>>
>> Since some of his measurements showed next to no current in some radials,
>> I figured right off the efficiency would almost always be higher with
>> equal
>> currents, even when using shorter radials of the same number. I never
>> needed to use elevated radials, so it was all merely academic for me.
>>
>> I'll bet anything you have very unequal currents in your elevated radials
>> despite their being precisely the same physical length. Dick's article
>> shows how he measured the currents with a simple HB device. Don't know
>> if
>> it is simpler than W8JI's or not.
>>
>
>
> ------------------------------
>
> Subject: Digest Footer
>
> _______________________________________________
> Topband mailing list
> Topband at contesting.com
> http://lists.contesting.com/mailman/listinfo/topband
>
>
> ------------------------------
>
> End of Topband Digest, Vol 129, Issue 29
> ****************************************
>
>
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