Hi Jeff,
I MAY be able to find you one of these and will check Monday a.m. We
normally refer tower stuff to Tex Tower but I have a source that handled
this same part in past. I don't know why these are not prevalent but I'm
guessing that the demand is very low and/or hams might resort to the less
expensive
base plate for guyed tower, not that this is recommended by any means. I
will contact your direct email on Monday.
73, Steve , K1PEK,
DAVIS RF Co.
Wire, Cable, RF Connectors and wire aerial parts. LMR, Heliax, Eupen,
PolyPhaser
Tel: 978-369-1738 Fax: 978-369-3484
www.davisRF.com
Message: 10
> Date: Sat, 14 Jun 2008 18:34:56 -0700
> From: Jeff Stevens <jeff@mossycup.com>
> Subject: [TowerTalk] Why is the 25GSSB Base Plate Difficult to Find?
> To: towertalk@contesting.com
> Message-ID: <1213493696.7016.26.camel@smoker.int.mossycup.com>
> Content-Type: text/plain
>
> I'm looking to put up a 28' bracketed Rohn 25 tower for some VHF/UHF
> antennas. There is definitely an ample supply of used tower sections,
> house brackets, top sections, etc. in good to excellent condition. So
> far, however, I haven't found anyone willing to part with a base plate.
>
> Looking online for the 25GSSB self supporting base plate I've found they
> are not easily purchased new either. Why is this? Neither tessco nor
> Texas Towers sells them. Both the BPC25G pinned base plate and BPH25G
> tilt over base plate are readily available. Does anybody know why the
> 25GSSB is so difficult to find new?
>
> -Jeff
> KE7FRJ
>
----- Original Message -----
From: <towertalk-request@contesting.com>
To: <towertalk@contesting.com>
Sent: Sunday, June 15, 2008 12:24 AM
Subject: TowerTalk Digest, Vol 66, Issue 40
> Send TowerTalk mailing list submissions to
> towertalk@contesting.com
>
> To subscribe or unsubscribe via the World Wide Web, visit
> http://lists.contesting.com/mailman/listinfo/towertalk
> or, via email, send a message with subject or body 'help' to
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>
> When replying, please edit your Subject line so it is more specific
> than "Re: Contents of TowerTalk digest..."
>
>
> Today's Topics:
>
> 1. Re: Vert. 1/2 wave dipole vs Hori. 1/2 wave dipole?
> (Peter Voelpel)
> 2. Re: Vert. 1/2 wave dipole vs Hori. 1/2 wave dipole? (Kim Elmore)
> 3. FS 3 el 40m beam (Peter)
> 4. Re: Vert. 1/2 wave dipole vs Hori. 1/2 wave dipole?
> (Peter Voelpel)
> 5. Turn Buckles (AD5VJ Bob)
> 6. Re: dipole in space question (Jim Brown)
> 7. Dutton-Lainson Brake Winch (John Hudson)
> 8. Re: Dutton-Lainson Brake Winch (Alan NV8A)
> 9. Re: Vert. 1/2 wave dipole vs Hori. 1/2 wave dipole? (Richards)
> 10. Why is the 25GSSB Base Plate Difficult to Find? (Jeff Stevens)
> 11. Tri Ex MW 65 Tower (Larrbeard@aol.com)
> 12. Re: Vert. 1/2 wave dipole vs Hori. 1/2 wave dipole? (Rob Atkinson)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Sat, 14 Jun 2008 18:01:22 +0200
> From: "Peter Voelpel" <df3kv@t-online.de>
> Subject: Re: [TowerTalk] Vert. 1/2 wave dipole vs Hori. 1/2 wave
> dipole?
> To: <towertalk@contesting.com>
> Message-ID: <5043E331FEAD4BC498D465EEF6EE5E62@ap200>
> Content-Type: text/plain; charset="us-ascii"
>
>
> A 1/4 wave 80m vertical series fed on 40m is nothing else then a halve
> wave
> vertical on 40m which was questioned about.
> A vertical dipol can be fed at one end, center feed is no must.
> Radials are useful below ALL kinds of vertical antennas anyway.
>
> 73
> Peter
>
> -----Original Message-----
> From: Richards [mailto:jruing@ameritech.net]
> Sent: Samstag, 14. Juni 2008 17:28
> To: Peter Voelpel
> Cc: towertalk@contesting.com
> Subject: Re: [TowerTalk] Vert. 1/2 wave dipole vs Hori. 1/2 wave dipole?
>
> Are you talking apples to apples?
>
> I thought the question was a vertical dipole vs a horizontal dipole of the
> same size.
>
> It sounds to me like you have a vertical with radials vs a horizontal
> dipole
> ...
>
> /////////////// K8JHR ///////////////
>
>
> Peter Voelpel wrote:
>
>> I used a L-tuner with my 1/4 80m vertical above 3km of radials 20-30m
>> long and used an inverted-V dipol at 30m height, ends at 20m. Distance
>> between antennas 150m with negiable line losses.
>
>
> ===================================================================
>
>
>
> ------------------------------
>
> Message: 2
> Date: Sat, 14 Jun 2008 12:03:11 -0500
> From: Kim Elmore <cw_de_n5op@sbcglobal.net>
> Subject: Re: [TowerTalk] Vert. 1/2 wave dipole vs Hori. 1/2 wave
> dipole?
> To: towertalk@contesting.com
> Message-ID: <20080614170314.4479A1B607F7@dayton.contesting.com>
> Content-Type: text/plain; charset="us-ascii"; format=flowed
>
> I dare say that radials are useful under *any* kind of antenna.
> Anything we can do to decrease ground losses is a Good Thing.
>
> A vertical 1/2 wave antenna isn't fed "against" ground as is a 1/4
> wave vertical. Ground currents are a minimum at the base of a 1/2
> wave vertical, and the current loop is distributed much further out,
> over more area, which means that the current density is reduced, So,
> the magnitude of the current is less, which means that the ground
> losses are proportionately reduced. though not eliminated. Current at
> the base of a 1/4 wave vertical is a maximum, and ground losses are a
> much more immediate concern.
>
> Ideally, we'd place our antennas on an infinitely flat plane made of
> copper, but the expense tends to be the zero-order limit on our
> ability to do that.
>
> Kim N5OP
>
>
>
> At 11:01 AM 6/14/2008, you wrote:
>
>>A 1/4 wave 80m vertical series fed on 40m is nothing else then a halve
>>wave
>>vertical on 40m which was questioned about.
>>A vertical dipol can be fed at one end, center feed is no must.
>>Radials are useful below ALL kinds of vertical antennas anyway.
>>
>>73
>>Peter
>>
>>-----Original Message-----
>>From: Richards [mailto:jruing@ameritech.net]
>>Sent: Samstag, 14. Juni 2008 17:28
>>To: Peter Voelpel
>>Cc: towertalk@contesting.com
>>Subject: Re: [TowerTalk] Vert. 1/2 wave dipole vs Hori. 1/2 wave dipole?
>>
>>Are you talking apples to apples?
>>
>>I thought the question was a vertical dipole vs a horizontal dipole of the
>>same size.
>>
>>It sounds to me like you have a vertical with radials vs a horizontal
>>dipole
>>...
>>
>>/////////////// K8JHR ///////////////
>>
>>
>>Peter Voelpel wrote:
>>
>> > I used a L-tuner with my 1/4 80m vertical above 3km of radials 20-30m
>> > long and used an inverted-V dipol at 30m height, ends at 20m. Distance
>> > between antennas 150m with negiable line losses.
>>
>>
>>===================================================================
>>
>>_______________________________________________
>>
>>
>>
>>_______________________________________________
>>TowerTalk mailing list
>>TowerTalk@contesting.com
>>http://lists.contesting.com/mailman/listinfo/towertalk
>
>
>
> ------------------------------
>
> Message: 3
> Date: Sat, 14 Jun 2008 17:25:32 +0000
> From: Peter <pc2a@pi4cc.nl>
> Subject: [TowerTalk] FS 3 el 40m beam
> To: Towertalk List <towertalk@contesting.com>
> Message-ID: <4853FF0C.5080102@pi4cc.nl>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> Hi
>
> Due problems with a new landlord I have for sale a all most finished
> home made full size 3 el 40 meter beam per description in ON4UN lowband
> dx-ing
> Prefer pick-up in The Netherlands.
>
> Pictures on request.
>
> Peter
> PC2A
>
>
> ------------------------------
>
> Message: 4
> Date: Sat, 14 Jun 2008 21:23:23 +0200
> From: "Peter Voelpel" <df3kv@t-online.de>
> Subject: Re: [TowerTalk] Vert. 1/2 wave dipole vs Hori. 1/2 wave
> dipole?
> To: <towertalk@contesting.com>
> Message-ID: <37D6480C959440A087D571355A011651@ap200>
> Content-Type: text/plain; charset="iso-8859-1"
>
> The bobtail curtain array as well as the halfsquare is using vertical
> elements a 1/4 wave high.
> Feeding a half wave vertical from top or bottom makes no difference at
> all,
> it is high impedance at the ends.
>
> 73
> Peter
>
> -----Original Message-----
> From: KZ4USA [mailto:videorov@verizon.net]
> Sent: Samstag, 14. Juni 2008 20:52
> To: Peter Voelpel
> Subject: Re: [TowerTalk] Vert. 1/2 wave dipole vs Hori. 1/2 wave dipole?
>
> Try feedig at top like a bobtail curtain vertical array.
>
>
> http://www.hamradioclassifieds.com
> List Your Equipment with Pictures.
> Jack
> Bradenton, Florida
> West Coast Of Florida
> http://www.hamradioclassifieds.com/webcams.html
> KZ4USA
>
> http://www.camradio.net/Page1CAMS.html
> ----- Original Message -----
> From: "Peter Voelpel" <df3kv@t-online.de>
> To: <towertalk@contesting.com>
> Sent: Saturday, June 14, 2008 3:37 AM
> Subject: Re: [TowerTalk] Vert. 1/2 wave dipole vs Hori. 1/2 wave dipole?
>
>
> I did that comparison on 40m with dx stations only and it was a big
> difference.
> I used a L-tuner with my 1/4 80m vertical above 3km of radials 20-30m long
> and used an inverted-V dipol at 30m height, ends at 20m. Distance between
> antennas 150m with negiable line losses.
> The dipol always outperformed the vertical by at least 6dbs in any
> direction, on some signals the difference was approaching 10db.
> The feedpoint of the vertical was very close to ground. I guess that it
> was
> attenuated by the near ground and should have been much higher with it?s
> feed point to perform better.
>
> 73
> Peter
>
>
>
> -----Original Message-----
> From: towertalk-bounces@contesting.com
> [mailto:towertalk-bounces@contesting.com] On Behalf Of fraz1
>
> I am very familiar with the "models". Does anyone have hands-on A/B
> experience with these two antennas that can share their actual findings?
> I'm talking in the 40M-20M range.
>
>
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>
>
>
> ------------------------------
>
> Message: 5
> Date: Sat, 14 Jun 2008 14:23:45 -0500
> From: "AD5VJ Bob" <rtnmi@sbcglobal.net>
> Subject: [TowerTalk] Turn Buckles
> To: <towertalk@contesting.com>
> Message-ID: <01ac01c8ce54$2a840910$6601a8c0@RAD9FBHB71>
> Content-Type: text/plain; charset="US-ASCII"
>
> What determines the length on turnbuckles 8", 12", 18" ect
>
> and if I am using 3/16 EHS cable what to I want for eye size?
>
>
> 73 fer nw es gud DX,
> QSL VIA: LotW, BUR, e-QSL
> Bob AD5VJ
> http://www.ad5vj.com/
> Old Calls WB5ZQU, WY5L/KH3, KE5CTY, N5IET
>
>
>
>
> ------------------------------
>
> Message: 6
> Date: Sat, 14 Jun 2008 12:52:58 -0700
> From: "Jim Brown" <jim@audiosystemsgroup.com>
> Subject: Re: [TowerTalk] dipole in space question
> To: "towertalk@contesting.com" <towertalk@contesting.com>
> Message-ID: <20080614195300.2DAF5593A1@gw1.nlenet.net>
> Content-Type: text/plain; charset="us-ascii"
>
> On Thu, 12 Jun 2008 08:59:20 -0700, Al Williams wrote:
>
>>Yes the current is strongest at the center, but why?
>
>>From a current/voltage point of view, an antenna can be thought of
> as a transmission line of that length. Current and voltage along a
> line varies as a standing wave and repeat in half-wavelengths. Since
> the END of the antenna is an open circuit, the current MUST be zero
> at the end, and the voltage is a maximum. A mathematician would call
> this a "boundary condition" for the equations he would write.
>
> 1/4 wavelength from the end the CURRENT reaches its maximum and the
> VOLTAGE drops to its minimum. The dipole is resonant at the
> frequency where it's a quarter-wave length to each end (or an odd
> number of quarter wavelengths to each end) because this makes the
> standing wave patterns "nice" -- that is, they reinforce each other.
> It's like a resonant circuit, where energy is traded back and forth
> between the L and the C when XL = XC.
>
> 73,
>
> Jim Brown K9YC
>
>
>
>
>
>
>
> ------------------------------
>
> Message: 7
> Date: Sat, 14 Jun 2008 15:02:37 -0500
> From: "John Hudson" <jd_hudson@comcast.net>
> Subject: [TowerTalk] Dutton-Lainson Brake Winch
> To: <towertalk@contesting.com>
> Message-ID: <000f01c8ce59$99221ce0$cb6656a0$@net>
> Content-Type: text/plain; charset="us-ascii"
>
> Anyone have good/bad experience with the Dutton-Lainson Brake Winch 2,500
> lbs vs. the Fulton K2550. sells for 142.00 from one website. The DL is
> 12:1
> ratio
>
>
>
> Going on a TX-455 for cranking up/down and another for raising/lowering
> with
> a homebrew fixture.
>
>
>
> Thanks for any input
>
>
>
>
>
> 73
>
>
>
> John
>
> KO4XJ
> www.w4nja.org/ko4xj.htm
>
>
>
>
>
> ------------------------------
>
> Message: 8
> Date: Sat, 14 Jun 2008 17:10:13 -0400
> From: Alan NV8A <nv8a@att.net>
> Subject: Re: [TowerTalk] Dutton-Lainson Brake Winch
> To: towertalk reflector <towertalk@contesting.com>
> Cc: John Hudson <jd_hudson@comcast.net>
> Message-ID: <485433B5.60506@att.net>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> On 06/14/08 04:02 pm John Hudson wrote:
>
>> Anyone have good/bad experience with the Dutton-Lainson Brake Winch 2,500
>> lbs vs. the Fulton K2550. sells for 142.00 from one website. The DL is
>> 12:1
>> ratio
>>
>> Going on a TX-455 for cranking up/down and another for raising/lowering
>> with
>> a homebrew fixture.
>
> I have never heard of that brand, but the K2550 is only $179.95 at
>
> http://www.crofttrailer.com/site/products/199/201/1477/details.html
>
> -- maybe less than you were thinking you would have to pay.
>
> 73
>
> Alan NV8A
>
>
>
> ------------------------------
>
> Message: 9
> Date: Sat, 14 Jun 2008 19:07:55 -0400
> From: Richards <jruing@ameritech.net>
> Subject: Re: [TowerTalk] Vert. 1/2 wave dipole vs Hori. 1/2 wave
> dipole?
> To: Peter Voelpel <df3kv@t-online.de>
> Cc: towertalk@contesting.com
> Message-ID: <48544F4B.9000904@ameritech.net>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
>
> thanks -- I am learning all the time. Thanks for knowing it
> was a serious question.
>
> Happy trails. // K8JHR //
>
> ============================================================
>
> Peter Voelpel wrote:
>> A 1/4 wave 80m vertical series fed on 40m is nothing else then a halve
>> wave
>> vertical on 40m which was questioned about.
>> A vertical dipol can be fed at one end, center feed is no must.
>> Radials are useful below ALL kinds of vertical antennas anyway.
> =============================================================
>
>
> ------------------------------
>
> Message: 10
> Date: Sat, 14 Jun 2008 18:34:56 -0700
> From: Jeff Stevens <jeff@mossycup.com>
> Subject: [TowerTalk] Why is the 25GSSB Base Plate Difficult to Find?
> To: towertalk@contesting.com
> Message-ID: <1213493696.7016.26.camel@smoker.int.mossycup.com>
> Content-Type: text/plain
>
> I'm looking to put up a 28' bracketed Rohn 25 tower for some VHF/UHF
> antennas. There is definitely an ample supply of used tower sections,
> house brackets, top sections, etc. in good to excellent condition. So
> far, however, I haven't found anyone willing to part with a base plate.
>
> Looking online for the 25GSSB self supporting base plate I've found they
> are not easily purchased new either. Why is this? Neither tessco nor
> Texas Towers sells them. Both the BPC25G pinned base plate and BPH25G
> tilt over base plate are readily available. Does anybody know why the
> 25GSSB is so difficult to find new?
>
> -Jeff
> KE7FRJ
>
>
>
> ------------------------------
>
> Message: 11
> Date: Sat, 14 Jun 2008 20:56:29 EDT
> From: Larrbeard@aol.com
> Subject: [TowerTalk] Tri Ex MW 65 Tower
> To: towertalk@contesting.com
> Message-ID: <c96.269b8bab.3585c2bd@aol.com>
> Content-Type: text/plain; charset="US-ASCII"
>
> Does anyone have any installation data on the Tri Ex MW 65? - wind loads,
> how big a chunk of concrete is needed for a base, details of recommended
> re-bar
> structure in the base.
>
> de WB9UFS/LarrBeard@aol.com
>
>
> **************
> Vote for your city's best dining and
> nightlife. City's Best 2008.
>
> (http://citysbest.aol.com?ncid=aolacg00050000000102)
>
>
> ------------------------------
>
> Message: 12
> Date: Sat, 14 Jun 2008 23:24:04 -0500
> From: "Rob Atkinson" <ranchorobbo@gmail.com>
> Subject: Re: [TowerTalk] Vert. 1/2 wave dipole vs Hori. 1/2 wave
> dipole?
> To: towertalk@contesting.com
> Message-ID:
> <d2bb1cb80806142124i338792f8w18da77aa3d3904e1@mail.gmail.com>
> Content-Type: text/plain; charset=ISO-8859-1
>
> <<<A 1/4 wave 80m vertical series fed on 40m is nothing else then a halve
> wave
> vertical on 40m which was questioned about.>>>
>
> No, the question had to do with one half wave length DIPOLEs,
> vertically and horizontally polarized. They may be symmetric or
> asymmetric but a DIpole has two poles right? a conductor fed at the
> end (base fed vertically polarized in this case) that is 1/2 wave
> length against a ground screen is not a DIpole, but it IS 180 degrees
> long (tall) for some frequency.
>
> <<<A vertical dipol can be fed at one end, center feed is no must.>>>
> Center feed is not necessary; feed point can be off-center, but it's
> NOT a DIPOLE if fed at one end; what you have is a MONOpole which is
> not what the question was about.
>
> <<<Radials are useful below ALL kinds of vertical antennas anyway.>>>
>
> Especially on sand. : )
>
> 73
>
> rob / k5uj
>
>
> ------------------------------
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>
>
> End of TowerTalk Digest, Vol 66, Issue 40
> *****************************************
>
>
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