This post is the best evidence ever that "Top Posting" is a good Idea.
Bill--W4BSG
----- Original Message -----
From: "gw3jxn" <gw3jxn@tiscali.co.uk>
To: <topband@contesting.com>
Sent: Sunday, May 06, 2012 3:27 AM
Subject: Re: Topband: Topband Digest, Vol 113, Issue 8
>
> ----- Original Message -----
> From: <topband-request@contesting.com>
> To: <topband@contesting.com>
> Sent: Saturday, May 05, 2012 7:00 PM
> Subject: Topband Digest, Vol 113, Issue 8
>
>
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>>
>> Today's Topics:
>>
>> 1. Re: Fwd: radals fer 160m vertcal (Jim WA9YSD)
>> 2. Re: Fwd: radals fer 160m vertcal (ZR)
>> 3. Re: Fwd: radals fer 160m vertcal (Charlie Young)
>> 4. Re: Fwd: radals fer 160m vertcal (Richard Fry)
>> 5. Re: Fwd: radals fer 160m vertcal (James Rodenkirch)
>> 6. Radials on top band (John Harden)
>> 7. Re: Fwd: radals fer 160m vertcal (Mike Waters)
>>
>>
>> ----------------------------------------------------------------------
>>
>> Message: 1
>> Date: Sat, 5 May 2012 07:00:08 -0700 (PDT)
>> From: Jim WA9YSD <wa9ysd@yahoo.com>
>> Subject: Re: Topband: Fwd: radals fer 160m vertcal
>> To: Top Band <topband@contesting.com>
>> Message-ID:
>> <1336226408.63699.YahooMailNeo@web111714.mail.gq1.yahoo.com>
>> Content-Type: text/plain; charset=iso-8859-1
>>
>> Keep in mind this Sole purpose of a BC station is to get coverage of
>> about
>> 60 miles running 5KW day time and 1 KW night time with no fad and quality
>> signal not to work DX.
>>
>> I read in some posts or on some web site that it does not matter if the
>> ends are tied to a ground rod or not.??Note then ends not at the base of
>> the vertical.
>>
>> My backyard is only 35 by 36 feet.??You guys only think you have a small
>> back yard.??Compare it with this one.
>>
>> The City water pipe system sure works as the good ground I guess so does
>> the neighbors plumbing cause their house in only 8 feet from mine :-)
>>
>> Jim K9TF
>> ?
>> Stay on course, fight a good fight, and keep the faith.?Jim K9TF/WA9YSD
>>
>> ------------------------------
>>
>> Message: 2
>> Date: Sat, 5 May 2012 10:34:06 -0400
>> From: "ZR" <zr@jeremy.mv.com>
>> Subject: Re: Topband: Fwd: radals fer 160m vertcal
>> To: "Richard Fry" <rfry@adams.net>, <topband@contesting.com>
>> Message-ID: <F637FEFE70F444C692A62D16142B015F@computer1>
>> Content-Type: text/plain; format=flowed; charset="iso-8859-1";
>> reply-type=original
>>
>> There have been several reports of established AM stations that the FCC
>> gave
>> permission to replace a decayed or destroyed inground radial system with
>> elevated radials or an elevated mesh/radial arrangement.
>>
>> In all the cases I read the FS measurements exceed the original and power
>> had to be reduced to the original level.
>>
>> Carl
>> KM1H
>>
>>
>> ----- Original Message -----
>> From: "Richard Fry" <rfry@adams.net>
>> To: <topband@contesting.com>
>> Sent: Saturday, May 05, 2012 8:07 AM
>> Subject: Re: Topband: Fwd: radals fer 160m vertcal
>>
>>
>>> James Rodenkirch wrote:
>>>>What about radials above the ground?
>>>
>>> This link http://www.commtechrf.com/documents/nab1995.pdf leads to a
>>> paper
>>> by Clarence Beverage with some real-world results for monopoles with
>>> elevated wires used as a counterpoise. Here is a quote from it:
>>>
>>>
>>> \ \The antenna system consisted of a lightweight, 15 inch face tower,
>>> 120
>>> feet in height, with a base insulator at the 15 foot elevation and six
>>> elevated radials, a quarter wave in length, spaced evenly around the
>>> tower
>>> and elevated 15 feet above the ground. The radials were fully insulated
>>> from
>>> ground and supported at the ends by wooden tripods.
>>>
>>> Power was fed to the system through a 200 foot length of coaxial cable
>>> with
>>> the cable shield connected to the shunt element of the T network and to
>>> the
>>> elevated radials. A balun or RF choke on the feedline was not employed
>>> and
>>> the feedline was isolated from the lower section of the tower. The
>>> system
>>> operated on 1580 kHz at a power of 750 watts.
>>>
>>> The efficiency of the antenna was determined by radial field intensity
>>> measurements along 12 radials extending out to a distance of up to 85
>>> kilometers. The measured RMS efficiency was 287 mV/m for 1 kW, at one
>>> kilometer, which is the same measured value as would be expected for a
>>> 0.17
>>> wave tower above 120 buried radials. / /
>>>
>>>
>>> So while such "elevated" installations are rare for AM broadcast
>>> stations,
>>> their performance has been measured to be about the same as when using
>>> an
>>> r-f ground consisting of 120 buried wires, each 1/4-wave long (free
>>> space
>>> length).
>>>
>>> These elevated systems are readily modeled using NEC-2. However the
>>> radiation patterns shown by a typical NEC far-field analysis do not
>>> accurately show the fields actually "launched" by them, or by any
>>> vertical
>>> radiator with its base near the earth, because they do not include the
>>> surface wave.
>>>
>>> The fields radiated in and near the horizontal plane by any vertical
>>> monopole of 5/8 wavelength height and less are the greatest fields it
>>> radiates in the entire elevation plane, regardless of earth
>>> conductivity.
>>> Those fields from very low elevation angles (say, less then 5 degrees)
>>> can
>>> reach the ionosphere, and under the right conditions return to the earth
>>> as
>>> a useful skywave.
>>>
>>> The link below illustrates this concept.
>>>
>>> http://i62.photobucket.com/albums/h85/rfry-100/Space_Surface_Wave_Compare.gif
>>>
>>>
>>> _______________________________________________
>>> UR RST IS ... ... ..9 QSB QSB - hw? BK
>>>
>>>
>>> -----
>>> No virus found in this message.
>>> Checked by AVG - www.avg.com
>>> Version: 10.0.1424 / Virus Database: 2411/4978 - Release Date: 05/04/12
>>>
>>
>>
>>
>> ------------------------------
>>
>> Message: 3
>> Date: Sat, 5 May 2012 09:50:31 -0500
>> From: Charlie Young <weeksmgr@hotmail.com>
>> Subject: Re: Topband: Fwd: radals fer 160m vertcal
>> To: <rfry@adams.net>, <topband@contesting.com>
>> Message-ID: <SNT121-W31A9696DD0956B08138ADAD82D0@phx.gbl>
>> Content-Type: text/plain; charset="iso-8859-1"
>>
>>
>> Dick, thanks very much for posting the link for the Beverage elevated
>> counterpoise article. Very interesting reading.
>>
>> Also thanks for the surface wave vs skywave graphic.
>>
>>
>> 73 Chas N8RR
>>
>>
>>> From: rfry@adams.net
>>> To: topband@contesting.com
>>> Date: Sat, 5 May 2012 07:07:11 -0500
>>> Subject: Re: Topband: Fwd: radals fer 160m vertcal
>>>
>>> James Rodenkirch wrote:
>>> >What about radials above the ground?
>>>
>>> This link http://www.commtechrf.com/documents/nab1995.pdf leads to a
>>> paper
>>> by Clarence Beverage with some real-world results for monopoles with
>>> elevated wires used as a counterpoise. Here is a quote from it:
>>>
>>>
>>> \ \The antenna system consisted of a lightweight, 15 inch face tower,
>>> 120
>>> feet in height, with a base insulator at the 15 foot elevation and six
>>> elevated radials, a quarter wave in length, spaced evenly around the
>>> tower
>>> and elevated 15 feet above the ground. The radials were fully insulated
>>> from
>>> ground and supported at the ends by wooden tripods.
>>>
>>> Power was fed to the system through a 200 foot length of coaxial cable
>>> with
>>> the cable shield connected to the shunt element of the T network and to
>>> the
>>> elevated radials. A balun or RF choke on the feedline was not employed
>>> and
>>> the feedline was isolated from the lower section of the tower. The
>>> system
>>> operated on 1580 kHz at a power of 750 watts.
>>>
>>> The efficiency of the antenna was determined by radial field intensity
>>> measurements along 12 radials extending out to a distance of up to 85
>>> kilometers. The measured RMS efficiency was 287 mV/m for 1 kW, at one
>>> kilometer, which is the same measured value as would be expected for a
>>> 0.17
>>> wave tower above 120 buried radials. / /
>>>
>>>
>>> So while such "elevated" installations are rare for AM broadcast
>>> stations,
>>> their performance has been measured to be about the same as when using
>>> an
>>> r-f ground consisting of 120 buried wires, each 1/4-wave long (free
>>> space
>>> length).
>>>
>>> These elevated systems are readily modeled using NEC-2. However the
>>> radiation patterns shown by a typical NEC far-field analysis do not
>>> accurately show the fields actually "launched" by them, or by any
>>> vertical
>>> radiator with its base near the earth, because they do not include the
>>> surface wave.
>>>
>>> The fields radiated in and near the horizontal plane by any vertical
>>> monopole of 5/8 wavelength height and less are the greatest fields it
>>> radiates in the entire elevation plane, regardless of earth
>>> conductivity.
>>> Those fields from very low elevation angles (say, less then 5 degrees)
>>> can
>>> reach the ionosphere, and under the right conditions return to the earth
>>> as
>>> a useful skywave.
>>>
>>> The link below illustrates this concept.
>>>
>>> http://i62.photobucket.com/albums/h85/rfry-100/Space_Surface_Wave_Compare.gif
>>>
>>>
>>> _______________________________________________
>>> UR RST IS ... ... ..9 QSB QSB - hw? BK
>>
>>
>> ------------------------------
>>
>> Message: 4
>> Date: Sat, 5 May 2012 09:57:53 -0500
>> From: "Richard Fry" <rfry@adams.net>
>> Subject: Re: Topband: Fwd: radals fer 160m vertcal
>> To: "ZR" <zr@jeremy.mv.com>, <topband@contesting.com>
>> Message-ID: <48160BBF32D34941B2939C7D44EEC6C4@ToshLaptop>
>> Content-Type: text/plain; format=flowed; charset="iso-8859-1";
>> reply-type=response
>>
>> Carl KM1H wrote:
>>> There have been several reports of established AM stations that the FCC
>>> gave permission to replace a decayed or destroyed inground radial system
>>> with elevated radials or an elevated mesh/radial arrangement.
>>>
>>> In all the cases I read the FS measurements exceed the original and
>>> power
>>> had to be reduced to the original level.
>>
>> The FCC requires minimum "efficiencies" for the radiators of various
>> classes
>> of licensed AM broadcast stations, expressed as the r.m.s. field
>> intensity
>> of the ground wave produced at 1 km for 1 kW of power applied to the
>> antenna
>> system. The FCC doesn't have an upper limit for AM broadcast field
>> intensities except when a directional radiation pattern is required.
>>
>> For an example of the non-directional case, there are stations licensed
>> for
>> 1 kW on 1400 kHz that use 1/2-wave monopoles instead of 1/4-wave (or
>> shorter) monopoles. Such stations using 1/2-wave monopoles still use 1
>> kW
>> transmitters, produce higher fields at all distances, and have larger
>> useful
>> groundwave coverage areas than those using 1/4-wave and shorter
>> monopoles.
>> This is all perfectly legal.
>>
>>
>>
>> ------------------------------
>>
>> Message: 5
>> Date: Sat, 5 May 2012 09:12:18 -0600
>> From: James Rodenkirch <rodenkirch_llc@msn.com>
>> Subject: Re: Topband: Fwd: radals fer 160m vertcal
>> To: <rfry@adams.net>, <topband@contesting.com>
>> Message-ID: <SNT137-W17B94AC6B37214734AACD0F02D0@phx.gbl>
>> Content-Type: text/plain; charset="iso-8859-1"
>>
>>
>> Thank you, Richard, fore passing the paper on....looks like I won't
>> "suffer" by having elevated radials in the least. Jim R. K9JWV
>>
>>
>>
>> > From: rfry@adams.net
>>> To: topband@contesting.com
>>> Date: Sat, 5 May 2012 07:07:11 -0500
>>> Subject: Re: Topband: Fwd: radals fer 160m vertcal
>>>
>>> James Rodenkirch wrote:
>>> >What about radials above the ground?
>>>
>>> This link http://www.commtechrf.com/documents/nab1995.pdf leads to a
>>> paper
>>> by Clarence Beverage with some real-world results for monopoles with
>>> elevated wires used as a counterpoise. Here is a quote from it:
>>>
>>>
>>> \ \The antenna system consisted of a lightweight, 15 inch face tower,
>>> 120
>>> feet in height, with a base insulator at the 15 foot elevation and six
>>> elevated radials, a quarter wave in length, spaced evenly around the
>>> tower
>>> and elevated 15 feet above the ground. The radials were fully insulated
>>> from
>>> ground and supported at the ends by wooden tripods.
>>>
>>> Power was fed to the system through a 200 foot length of coaxial cable
>>> with
>>> the cable shield connected to the shunt element of the T network and to
>>> the
>>> elevated radials. A balun or RF choke on the feedline was not employed
>>> and
>>> the feedline was isolated from the lower section of the tower. The
>>> system
>>> operated on 1580 kHz at a power of 750 watts.
>>>
>>> The efficiency of the antenna was determined by radial field intensity
>>> measurements along 12 radials extending out to a distance of up to 85
>>> kilometers. The measured RMS efficiency was 287 mV/m for 1 kW, at one
>>> kilometer, which is the same measured value as would be expected for a
>>> 0.17
>>> wave tower above 120 buried radials. / /
>>>
>>>
>>> So while such "elevated" installations are rare for AM broadcast
>>> stations,
>>> their performance has been measured to be about the same as when using
>>> an
>>> r-f ground consisting of 120 buried wires, each 1/4-wave long (free
>>> space
>>> length).
>>>
>>> These elevated systems are readily modeled using NEC-2. However the
>>> radiation patterns shown by a typical NEC far-field analysis do not
>>> accurately show the fields actually "launched" by them, or by any
>>> vertical
>>> radiator with its base near the earth, because they do not include the
>>> surface wave.
>>>
>>> The fields radiated in and near the horizontal plane by any vertical
>>> monopole of 5/8 wavelength height and less are the greatest fields it
>>> radiates in the entire elevation plane, regardless of earth
>>> conductivity.
>>> Those fields from very low elevation angles (say, less then 5 degrees)
>>> can
>>> reach the ionosphere, and under the right conditions return to the earth
>>> as
>>> a useful skywave.
>>>
>>> The link below illustrates this concept.
>>>
>>> http://i62.photobucket.com/albums/h85/rfry-100/Space_Surface_Wave_Compare.gif
>>>
>>>
>>> _______________________________________________
>>> UR RST IS ... ... ..9 QSB QSB - hw? BK
>>
>>
>> ------------------------------
>>
>> Message: 6
>> Date: Sat, 05 May 2012 13:02:26 -0400
>> From: John Harden <jhdmd@bellsouth.net>
>> Subject: Topband: Radials on top band
>> To: topband@contesting.com
>> Message-ID: <4FA55D22.6030408@bellsouth.net>
>> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>>
>> I can work anything I can hear on 160. That's the whole deal... If I
>> can't hear it on the Hi-Z 4-square I can't work it......
>>
>> I have a 45G 100 foot tower shunt fed with an Omega match of vacuum
>> variables. I am always flat as the variable to ground is motor driven. I
>> have 32 radials..... At this point the curve starts to become
>> asymptotic. But, I still plan to add 32 more before the next top band
>> season....
>>
>> I've really enjoyed hearing all of the theory. It is in the books...all
>> of it...
>>
>> I have one book here entitled "Electromagnetics" by the late John Krause
>> (W8JK, SK) of the EE department of Ohio State Univ. The book has all of
>> the theory (if you can do calculus and differential equations) to
>> substantiate the fact that 120 radials is optimal.... He goes way beyond
>> opinions and assertions. All of his statements are guided by double
>> blind scientific studies..
>>
>> I had a quiz question at GA Tech eons ago. The question was "why is the
>> sky blue"? You couldn't BS those guys there. It took 5 pages of calculus
>> to answer it... It had to do with electrons going from one energy level
>> to another....
>>
>> Go get 'em on top band..
>>
>> 73,
>>
>> John, W4NU
>> K4JAG (1959 to 1998)
>>
>>
>>
>>
>> ------------------------------
>>
>> Message: 7
>> Date: Sat, 5 May 2012 13:33:35 -0500
>> From: Mike Waters <mikewate@gmail.com>
>> Subject: Re: Topband: Fwd: radals fer 160m vertcal
>> To: topband <topband@contesting.com>
>> Message-ID:
>> <CA+FxYXicETxooHVBnLm__5vDkcAKEFerR74v1542L5ztXkVJtg@mail.gmail.com>
>> Content-Type: text/plain; charset=ISO-8859-1
>>
>> Thanks for the wisdom, Rich. :-)
>>
>> However, I've always wondered about the following statement. My question
>> is, on what amateur bands is this common? And on what amateur bands is
>> this
>> possible?
>>
>> On Sat, May 5, 2012 at 7:07 AM, Richard Fry <rfry@adams.net> wrote:
>>
>>> Those fields from very low elevation angles (say, less then 5 degrees)
>>> can
>>> reach the ionosphere, and under the right conditions return to the earth
>>> as
>>> a useful skywave.
>>>
>>
>> 73, Mike
>> www.w0btu.com
>>
>>
>> ------------------------------
>>
>> _______________________________________________
>> Topband mailing list
>> Topband@contesting.com
>> http://lists.contesting.com/mailman/listinfo/topband
>>
>>
>> End of Topband Digest, Vol 113, Issue 8
>> ***************************************
>
> _______________________________________________
> UR RST IS ... ... ..9 QSB QSB - hw? BK
>
_______________________________________________
UR RST IS ... ... ..9 QSB QSB - hw? BK
|
