The catch here is in your last line. 4 inches diameter PVC pipe as a
coil form is probably well less than the minimum rated bend radius.
The coil will most likely see somewhat wide voltage/current swings as
well. Heating from inside and out will most likely be a problem.
But, I wouldn't let that stop me. I'd build it anyways with the
realization that in a few years the traps would need to be replaced.
By then we might come up with a better solution!
On Jul 20, 2008, at 8:11 AM, Steve Davis -Davis RF Co. wrote:
>
> Hi Jack, Your discussion is not over technical as your points are
> well put and fundamentally germane to the basics of coaxial design
> and function. The only catch is that it appears that you are
> skeptical that all cable jacket PVC's, and their PE dielectrics
> (both ref. RG-213 and many other similars) will not hold up to
> heating by the sun and resulting ambient transferred through the
> shield to the dielectric. There are many compounds of PVC jacket
> and PE dielectric used in cable extrusion. Choosing the proper
> types as I noted (or relying on the mfr.; distributor; or design
> engr), will hold up very well in any sunlight scenario for many
> years. PVC compounds certified at 60 deg. C., and UV resistant,
> are my requirement for outdoor applications of our RG-213 and
> similar cable.
> Your concerns are not uncommon and have been noticed in some of
> our commercial inquiries where they have spec'd Teflon outer
> jackets when the ambient would never reach in excess of 60 C, thus
> we've been able to save them a lot of money by using the correct
> grade of PVC.
> I agree completely with you ref. the electrical degradation due to
> center cond. concentricity misalignment, IF there is enough ambient
> heat combined with spiral exertion to cause this...however I do not
> expect the heating factor to be involved if the proper cable
> materials are utilized, inherent in a quality cable, and if the
> rated min. bend radius is adhered to.
> 73, Steve , K1PEK,
>
> DAVIS RF Co.
>
> Wire, Cable, RF Connectors and wire aerial parts. LMR, Heliax, Eupen
>
> Commercial / Military / & Custom Cable Design
>
> tel: 978-369-1738 Fax: 978-369-3484
> www.davisRF.com
>
>
>
> ----- Original Message ----- From: "Jack Brindle"
> <jackbrindle@earthlink.net>
> To: "Steve Davis -Davis RF Co." <sdavis@davisrf.com>
> Cc: <towertalk@contesting.com>
> Sent: Sunday, July 20, 2008 1:35 AM
> Subject: Re: [TowerTalk] Paintg Traps-Coax issues-Respon fr DAVIS
> RF Co.
>
>
>> It's not the outer jacket that would be the life-limiter in this
>> design, but it definitely contributes to the eventual problem.
>> Heat absorbed by the outer conductor and also that dissipated
>> between the center conductor and the shield will cause distortion
>> of the dielectric. The coax is wound in a loop with the
>> dielectric holding the center conductor in place. As the
>> dielectric softens due to the heat, it will allow the center
>> conductor to migrate outwards to its more natural form
>> (straighter, in less tension). Eventually the center conductor
>> will contact the shield and the trap will be useless. This
>> phenomenon happens faster in hot areas (i.e. the South) than in
>> more moderate climates, but it does happen in time over all.
>>
>> OK, so this was overly technical in the discussion, but the gist
>> is that the dielectric will melt and the center conductor will
>> short to the shield. The sun will heat darker colors more than
>> light colors, but in time the trap will fail. Anyone have a good
>> reference as to how long it will take? I have seen this happen in
>> just months in South Florida...
>>
>> On Jul 19, 2008, at 10:15 PM, Steve Davis -Davis RF Co. wrote:
>>
>>> Hi Dave, not sure if I am completely qualified to answer your
>>> question,
>>> but not seeing any response, I will throw my thoughts in. I can
>>> only say
>>> that from the prospective of the outer winding of RG-213, as
>>> long as you are
>>> using an RG-213 which has a Type-IIA outer jacket
>>> (PVC Type IIA), which is inherently a non-migrating type, AND if
>>> it ALSO is
>>> UV resistant (not all IIA is UV resistant, but all we supply for
>>> outdoor is
>>> both IIA and UV resistant, both of which is the ONLY way to go),
>>> then I
>>> wouldn't worry at all for some 15-20 years of jacket and
>>> internal life of
>>> the cable. There is a supplier, possibly suppliers, that sell
>>> a PVC jacket
>>> for outdoors that is NOT IIA , and also they CLAIM that it is
>>> buriable, but
>>> strictly by definition, if the jacket is PVC, there is no PVC
>>> being used
>>> currently that is truly buriable (another subject) . Ref. ur
>>> sched 40 trap
>>> core, whether or not the 213 outer winding is covering all or
>>> most of that
>>> core, I wouldn't be concerned with degradation of the sched 40,
>>> enough to
>>> make any difference in the assembly/function of the trap,
>>> certainly for the
>>> life period of the coax itself (15-20 years). The wall is more
>>> than thick
>>> enough to handled any UV that might hit it for such a period.
>>> Having said
>>> all that, I haven't actually seen the configuration you
>>> describe...if you
>>> have a picture or dwg, etc I'd be glad to look at it further.
>>> 73, Steve
>>> K1PEK JS/KJ/CC
>>> DAVIS RF Co.
>>> Wire, Cable, RF Connectors and wire aerial parts. LMR, Heliax,
>>> Eupen
>>>
>>> Commercial / Military / & Custom Cable Design
>>>
>>> tel: 978-369-1738 Fax: 978-369-3484
>>> www.DavisRF.com
>>>
>>>
>>>
>>>
>>> ----- Original Message -----
>>> From: <towertalk-request@contesting.com>
>>> To: <towertalk@contesting.com>
>>> Sent: Saturday, July 19, 2008 3:31 PM
>>> Subject: TowerTalk Digest, Vol 67, Issue 64
>>>
>>>
>>>> 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
>>>> towertalk-request@contesting.com
>>>>
>>>> You can reach the person managing the list at
>>>> towertalk-owner@contesting.com
>>>>
>>>> When replying, please edit your Subject line so it is more specific
>>>> than "Re: Contents of TowerTalk digest..."
>>>>
>>>>
>>>> Today's Topics:
>>>>
>>>> 1. Yagi Balun (walnutcreek@appstate.net)
>>>> 2. Re: Yagi Balun (Peter Voelpel)
>>>> 3. Re: another stupid guywire question (K5MLC (Mike))
>>>> 4. Fw: Tower MFG help (jody.n7ert)
>>>> 5. Fw: Tower MFG help (jody.n7ert)
>>>> 6. Fw: Tower MFG help (jody.n7ert)
>>>> 7. Fw: Tower MFG help (jody.n7ert)
>>>> 8. Painting Traps... (R. David Eagle)
>>>> 9. Re: Yagi Balun (Wes Attaway (N5WA))
>>>> 10. Long cable pull (K4SAV)
>>>> 11. Re: Long cable pull (John Ammeter)
>>>>
>>>>
>>>> -------------------------------------------------------------------
>>>> -- -
>>>>
>>>> Message: 1
>>>> Date: Sat, 19 Jul 2008 12:27:47 -0400
>>>> From: <walnutcreek@appstate.net>
>>>> Subject: [TowerTalk] Yagi Balun
>>>> To: <towertalk@contesting.com>
>>>> Message-ID: <1718503415.20080719122747@appstate.net>
>>>> Content-Type: text/plain; charset="iso-8859-1"
>>>>
>>>> I beg to differ...
>>>> I changed the baluns on my Telrex Monobanders, and a TB5EM to
>>>> 1:1 Ferrite
>>>> Choke Baluns that I built and they are working great with a 1:1
>>>> SWR and a
>>>> max at band edge of 1.6:1 SWR. They're all down and in stroage
>>>> right
>>>> now....moved.
>>>> Worked for me, just my experience.
>>>> 73 from afar,
>>>> Cam WA4JKW
>>>>
>>>>
>>>> I do believe that the Telrex monoband yagis employed the use of
>>>> a T match
>>>> in
>>>> the driven element. The impedance of a T match is not 50 ohms
>>>> but 400 to
>>>> 600 ohms. You would probably need a 9:1 Balun. A 1:1 Balun
>>>> will not
>>>> work.
>>>>
>>>> Bob W6TR
>>>>
>>>>
>>>>> Three 29 year old TELREX MONOBAND yagi's are off the towers
>>>>> and on the
>>>>> ground for maintenance and repairs. The factory made and
>>>>> installed coax
>>>>> baluns will be replaced. If the baluns are replaced with a
>>>>> ferrite-bead
>>>>> type 1:1 balun such as the Force-12 brand, will the antenna
>>>>> pattern or
>>>>> other factors be changed?
>>>>>
>>>>> Thanks.
>>>>>
>>>>> Bee K4JLD
>>>>> k4jld@juno.com
>>>>> __________________________________________________________
>>>>
>>>>
>>>>
>>>> ------------------------------
>>>>
>>>> Message: 2
>>>> Date: Sat, 19 Jul 2008 19:06:36 +0200
>>>> From: "Peter Voelpel" <df3kv@t-online.de>
>>>> Subject: Re: [TowerTalk] Yagi Balun
>>>> To: <towertalk@contesting.com>
>>>> Message-ID: <15D89687D24A408CA7130F6125518605@ap200>
>>>> Content-Type: text/plain; charset="us-ascii"
>>>>
>>>> Typically with a t-match the matching arms are adjusted for an
>>>> impedance
>>>> of
>>>> 200 ohms and then a halfwave coax 4:1 transformer is used for
>>>> matching to
>>>> 50
>>>> ohms unbalanced feedline.
>>>>
>>>> 73
>>>> Peter
>>>>
>>>> -----Original Message-----
>>>> From: towertalk-bounces@contesting.com
>>>> [mailto:towertalk-bounces@contesting.com] On Behalf Of Bob Maser
>>>> Sent: Samstag, 19. Juli 2008 04:09
>>>> To: towertalk@contesting.com; Bee Walton
>>>> Subject: Re: [TowerTalk] Yagi Balun
>>>>
>>>> I do believe that the Telrex monoband yagis employed the use of
>>>> a T match
>>>> in
>>>> the driven element. The impedance of a T match is not 50 ohms
>>>> but 400 to
>>>> 600 ohms. You would probably need a 9:1 Balun. A 1:1 Balun
>>>> will not
>>>> work.
>>>>
>>>> Bob W6TR
>>>> ----- Original Message -----
>>>> From: "Bee Walton" <k4jld@juno.com>
>>>> To: <towertalk@contesting.com>
>>>> Sent: Friday, July 18, 2008 6:24 PM
>>>> Subject: [TowerTalk] Yagi Balun
>>>>
>>>>
>>>>> Three 29 year old TELREX MONOBAND yagi's are off the towers
>>>>> and on the
>>>>> ground for maintenance and repairs. The factory made and
>>>>> installed coax
>>>>> baluns will be replaced. If the baluns are replaced with a
>>>>> ferrite-bead
>>>>> type 1:1 balun such as the Force-12 brand, will the antenna
>>>>> pattern or
>>>>> other factors be changed?
>>>>>
>>>>> Thanks.
>>>>>
>>>>> Bee K4JLD
>>>>> k4jld@juno.com
>>>>> ____________________________________________________________
>>>>> Need cash? Click to get a cash advance.
>>>>>
>>>> http://thirdpartyoffers.juno.com/TGL2141/fc/
>>>> Ioyw6i3mKeticKh9mZBzKeQwXuyJWoov
>>>> M4PBqFzJWojut7VXNbYh9C/
>>>>> _______________________________________________
>>>>>
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> TowerTalk mailing list
>>>>> TowerTalk@contesting.com
>>>>> http://lists.contesting.com/mailman/listinfo/towertalk
>>>>
>>>> _______________________________________________
>>>>
>>>>
>>>>
>>>> _______________________________________________
>>>> TowerTalk mailing list
>>>> TowerTalk@contesting.com
>>>> http://lists.contesting.com/mailman/listinfo/towertalk
>>>>
>>>>
>>>>
>>>> ------------------------------
>>>>
>>>> Message: 3
>>>> Date: Sat, 19 Jul 2008 10:10:27 -0700 (PDT)
>>>> From: "K5MLC \(Mike\)" <k5mlc@sbcglobal.net>
>>>> Subject: Re: [TowerTalk] another stupid guywire question
>>>> To: "Michael Fox \(K5MEF\)" <k5mef@mefox.org>
>>>> Cc: towertalk <towertalk@contesting.com>
>>>> Message-ID: <862535.94925.qm@web81907.mail.mud.yahoo.com>
>>>> Content-Type: text/plain; charset=iso-8859-1
>>>>
>>>> Very good question.? In my case, Michael, I just want something
>>>> with high
>>>> tensile strength?that is comparable with EHS specifications and
>>>> I found
>>>> that I could get the galvanized "aircraft cable" with the same
>>>> tensile
>>>> strength for about 2/3 of the cost of EHS. Yes, the
>>>> Phillistrand would be
>>>> an excellent alternative if I wanted?and had the extra cash to
>>>> spend. I've
>>>> researched?Rohn 25 tower guying specifications on the Rohn site and
>>>> made?my guying decisions based on that.?
>>>> OTOH, I live in an area that is subject to high winds from tropical
>>>> disturbances so I want to try to support the tower as much as I
>>>> can within
>>>> financial reason and good common sense.?I don't think guywire
>>>> with higher
>>>> tensile strength than EHS would have any benefit for me with a 51'
>>>> tower.?If we get a really big blow, survivability of the tower
>>>> is in
>>>> question -?chances are the tower is going to come down. I plan
>>>> on insuring
>>>> it and the rest of my equipment through the insurance plan with
>>>> the ARRL.
>>>> End of story. ?
>>>> 73 de K5MLC
>>>> Mike
>>>>
>>>> ----- Original Message ----
>>>> From: Michael Fox (K5MEF) <k5mef@mefox.org>
>>>> To: towertalk@contesting.com
>>>> Sent: Friday, July 18, 2008 5:02:47 PM
>>>> Subject: Re: [TowerTalk] another stupid guywire question
>>>>
>>>> I've been following the discussion about guy wires with great
>>>> interest.?
>>>> The
>>>> Phillystrand product is also very interesting.
>>>>
>>>> Please excuse my ignorance.? How does one go about determining
>>>> which
>>>> tensile
>>>> strength of Phillystrand (or any other material) is needed for a
>>>> particular
>>>> application?
>>>>
>>>> Michael K5MEF
>>>>
>>>>
>>>> _______________________________________________
>>>>
>>>>
>>>>
>>>> _______________________________________________
>>>> TowerTalk mailing list
>>>> TowerTalk@contesting.com
>>>> http://lists.contesting.com/mailman/listinfo/towertalk
>>>>
>>>>
>>>> ------------------------------
>>>>
>>>> Message: 4
>>>> Date: Sat, 19 Jul 2008 10:10:01 -0700
>>>> From: "jody.n7ert" <jody.n7ert@gmail.com>
>>>> Subject: [TowerTalk] Fw: Tower MFG help
>>>> To: <towertalk@contesting.com>
>>>> Message-ID: <000401c8e9c2$64225d00$d200a8c0@EchoTest>
>>>> Content-Type: text/plain; charset="iso-8859-1"
>>>>
>>>> Anyone seen this tower?? Seeking help to identify the
>>>> fabricator of a
>>>> tower.. I appears not to be Valmont/Pirod, ERI, or Radian/Rohn.
>>>> Each
>>>> section is bolted together with 6 ea 10" long 1" bolts, 2 per
>>>> leg... Top
>>>> section is marked with number 332142-2 and bottom section is
>>>> marked with
>>>> 332142-1,which has a 4 bolt flanges that mounts it to the
>>>> concrete tower
>>>> base 8'x8'x6'.. Face on tower is approx 36", Tower leg is 2"
>>>> solid rod.
>>>> Attached is link to picture that shows the metal ID tag and one
>>>> mounting
>>>> bolt section
>>>> Thanks, Jody N7ERT http://www.orednet.org/~jcross/tower1.jpg
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> ------------------------------
>>>>
>>>> Message: 5
>>>> Date: Sat, 19 Jul 2008 10:10:56 -0700
>>>> From: "jody.n7ert" <jody.n7ert@gmail.com>
>>>> Subject: [TowerTalk] Fw: Tower MFG help
>>>> To: <towertalk@contesting.com>
>>>> Message-ID: <000b01c8e9c2$6b496b00$d200a8c0@EchoTest>
>>>> Content-Type: text/plain; charset="iso-8859-1"
>>>>
>>>> Anyone seen this tower?? Seeking help to identify the
>>>> fabricator of a
>>>> tower.. I appears not to be Valmont/Pirod, ERI, or Radian/Rohn.
>>>> Each
>>>> section is bolted together with 6 ea 10" long 1" bolts, 2 per
>>>> leg... Top
>>>> section is marked with number 332142-2 and bottom section is
>>>> marked with
>>>> 332142-1,which has a 4 bolt flanges that mounts it to the
>>>> concrete tower
>>>> base 8'x8'x6'.. Face on tower is approx 36", Tower leg is 2"
>>>> solid rod.
>>>> Attached is link to picture that shows the metal ID tag and one
>>>> mounting
>>>> bolt section
>>>> Thanks, Jody N7ERT http://www.orednet.org/~jcross/tower1.jpg
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> ------------------------------
>>>>
>>>> Message: 6
>>>> Date: Sat, 19 Jul 2008 10:11:10 -0700
>>>> From: "jody.n7ert" <jody.n7ert@gmail.com>
>>>> Subject: [TowerTalk] Fw: Tower MFG help
>>>> To: <towertalk@contesting.com>
>>>> Message-ID: <001201c8e9c2$73937530$d200a8c0@EchoTest>
>>>> Content-Type: text/plain; charset="iso-8859-1"
>>>>
>>>> Anyone seen this tower?? Seeking help to identify the
>>>> fabricator of a
>>>> tower.. I appears not to be Valmont/Pirod, ERI, or Radian/Rohn.
>>>> Each
>>>> section is bolted together with 6 ea 10" long 1" bolts, 2 per
>>>> leg... Top
>>>> section is marked with number 332142-2 and bottom section is
>>>> marked with
>>>> 332142-1,which has a 4 bolt flanges that mounts it to the
>>>> concrete tower
>>>> base 8'x8'x6'.. Face on tower is approx 36", Tower leg is 2"
>>>> solid rod.
>>>> Attached is link to picture that shows the metal ID tag and one
>>>> mounting
>>>> bolt section
>>>> Thanks, Jody N7ERT http://www.orednet.org/~jcross/tower1.jpg
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> ------------------------------
>>>>
>>>> Message: 7
>>>> Date: Sat, 19 Jul 2008 10:12:50 -0700
>>>> From: "jody.n7ert" <jody.n7ert@gmail.com>
>>>> Subject: [TowerTalk] Fw: Tower MFG help
>>>> To: <towertalk@contesting.com>
>>>> Message-ID: <000c01c8e9c2$ae639c30$d200a8c0@EchoTest>
>>>> Content-Type: text/plain; charset="iso-8859-1"
>>>>
>>>> Anyone seen this tower?? Seeking help to identify the
>>>> fabricator of a
>>>> tower.. I appears not to be Valmont/Pirod, ERI, or Radian/Rohn.
>>>> Each
>>>> section is bolted together with 6 ea 10" long 1" bolts, 2 per
>>>> leg... Top
>>>> section is marked with number 332142-2 and bottom section is
>>>> marked with
>>>> 332142-1,which has a 4 bolt flanges that mounts it to the
>>>> concrete tower
>>>> base 8'x8'x6'.. Face on tower is approx 36", Tower leg is 2"
>>>> solid rod.
>>>> Attached is link to picture that shows the metal ID tag and one
>>>> mounting
>>>> bolt section
>>>> Thanks, Jody N7ERT http://www.orednet.org/~jcross/tower1.jpg
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> ------------------------------
>>>>
>>>> Message: 8
>>>> Date: Sat, 19 Jul 2008 12:13:24 -0700 (PDT)
>>>> From: "R. David Eagle" <kb8nnu@yahoo.com>
>>>> Subject: [TowerTalk] Painting Traps...
>>>> To: Tower Talk List <towertalk@contesting.com>
>>>> Message-ID: <963807.55399.qm@web51706.mail.re2.yahoo.com>
>>>> Content-Type: text/plain; charset=iso-8859-1
>>>>
>>>> Hello all...
>>>> I am in the process of putting a Battle Creek Special (trapper
>>>> edt.)
>>>> together and was wondering if I should paint the traps since
>>>> they will be
>>>> exposed to UV.? The traps are made out of 4'' PVC drain pipe
>>>> and is wound
>>>> with rg-213.? Will painting the traps affect the performance of
>>>> the traps
>>>> or should I not worry about it?
>>>> Thanks,
>>>> Dave
>>>> KB8NNU
>>>>
>>>>
>>>>
>>>>
>>>> ------------------------------
>>>>
>>>> Message: 9
>>>> Date: Sat, 19 Jul 2008 14:38:37 -0500
>>>> From: "Wes Attaway \(N5WA\)" <wesattaway@bellsouth.net>
>>>> Subject: Re: [TowerTalk] Yagi Balun
>>>> To: <walnutcreek@appstate.net>, <towertalk@contesting.com>
>>>> Message-ID: <65A63AB7F3E344D7831A9D34B8E490B1@OFFICE>
>>>> Content-Type: text/plain; charset="us-ascii"
>>>>
>>>> My 5-el Telrex 20M beam used a 4:1 transformer. I no longer
>>>> have that
>>>> antenna but I do know that was what it used.
>>>>
>>>> ------------------ Wes Attaway (N5WA) ------------------
>>>> 1138 Waters Edge Circle - Shreveport, LA 71106
>>>> 318-797-4972 (office) - 318-393-3289 (cell)
>>>> Computer Consulting and Forensics
>>>> -------------- EnCase Certified Examiner ---------------
>>>>
>>>> -----Original Message-----
>>>> From: towertalk-bounces@contesting.com
>>>> [mailto:towertalk-bounces@contesting.com] On Behalf Of
>>>> walnutcreek@appstate.net
>>>> Sent: Saturday, July 19, 2008 11:28 AM
>>>> To: towertalk@contesting.com
>>>> Subject: [TowerTalk] Yagi Balun
>>>>
>>>> I beg to differ...
>>>> I changed the baluns on my Telrex Monobanders, and a TB5EM to
>>>> 1:1 Ferrite
>>>> Choke Baluns that I built and they are working great with a 1:1
>>>> SWR and a
>>>> max at band edge of 1.6:1 SWR. They're all down and in stroage
>>>> right
>>>> now....moved.
>>>> Worked for me, just my experience.
>>>> 73 from afar,
>>>> Cam WA4JKW
>>>>
>>>>
>>>> I do believe that the Telrex monoband yagis employed the use of
>>>> a T match
>>>> in
>>>>
>>>> the driven element. The impedance of a T match is not 50 ohms
>>>> but 400 to
>>>> 600 ohms. You would probably need a 9:1 Balun. A 1:1 Balun
>>>> will not
>>>> work.
>>>>
>>>> Bob W6TR
>>>>
>>>>
>>>>> Three 29 year old TELREX MONOBAND yagi's are off the towers
>>>>> and on the
>>>>> ground for maintenance and repairs. The factory made and
>>>>> installed coax
>>>>> baluns will be replaced. If the baluns are replaced with a
>>>>> ferrite-bead
>>>>> type 1:1 balun such as the Force-12 brand, will the antenna
>>>>> pattern or
>>>>> other factors be changed?
>>>>>
>>>>> Thanks.
>>>>>
>>>>> Bee K4JLD
>>>>> k4jld@juno.com
>>>>> __________________________________________________________
>>>>
>>>> _______________________________________________
>>>>
>>>>
>>>>
>>>> _______________________________________________
>>>> TowerTalk mailing list
>>>> TowerTalk@contesting.com
>>>> http://lists.contesting.com/mailman/listinfo/towertalk
>>>>
>>>>
>>>>
>>>> ------------------------------
>>>>
>>>> Message: 10
>>>> Date: Sat, 19 Jul 2008 17:13:53 -0500
>>>> From: K4SAV <RadioIR@charter.net>
>>>> Subject: [TowerTalk] Long cable pull
>>>> To: towertalk@contesting.com
>>>> Message-ID: <48826721.2060703@charter.net>
>>>> Content-Type: text/plain; charset=us-ascii; format=flowed
>>>>
>>>> After being disappointed in the direct burial method, I am
>>>> planning on
>>>> adding some conduit to access my low band receiving antennas. I
>>>> have
>>>> one section of conduit that is 500 feet. Can I do this with
>>>> one pull,
>>>> or will I be wishing a I had added an access box and broken the
>>>> pull up
>>>> into two parts? I have never pulled a 500 ft run before. Since
>>>> it is
>>>> unlikely that I will ever want to add another cable into this
>>>> conduit, I
>>>> was planning on using 1.5 inch conduit. The run will be
>>>> straight except
>>>> for a couple of very long curves and then the curve at the exit
>>>> out of
>>>> the ground at the ends. I need to pull one run of RG6 and one
>>>> run of 16
>>>> ga landscape lightning cable for dc.
>>>>
>>>> Before someone suggests sending the dc down the RG6 to eliminate a
>>>> cable, the dc resistance of 635 ft of RG6 is about 22 ohms.
>>>> (It's 625
>>>> ft total to get to the operating position.) Besides the RG6
>>>> already has
>>>> dc controls signals on it as well as RF.
>>>>
>>>> Second question: What is a good method of putting the pull
>>>> string in a
>>>> conduit this long? I have put it there when building the
>>>> conduit, but
>>>> that is a pain. I have used an air compressor to blow a string
>>>> tied to
>>>> a rag thru the conduit, but never on a conduit this long. Is that
>>>> likely to work?
>>>>
>>>> Jerry, K4SAV
>>>>
>>>>
>>>> ------------------------------
>>>>
>>>> Message: 11
>>>> Date: Sat, 19 Jul 2008 15:31:17 -0700
>>>> From: John Ammeter <jammeter@cablespeed.com>
>>>> Subject: Re: [TowerTalk] Long cable pull
>>>> To: K4SAV <RadioIR@charter.net>
>>>> Cc: towertalk@contesting.com
>>>> Message-ID: <48826B35.2080507@cablespeed.com>
>>>> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>>>>
>>>> You can probably use a "mouse" and a shop vacuum to get the first
>>>> lightweight pull string down the conduit. Use the lightweight
>>>> string to
>>>> pull a stronger pull rope. I've never pulled 500 feet but with
>>>> virtually a straight run I doubt you'll have any trouble. I'm
>>>> not sure
>>>> if pulling grease is compatible with RG6 and you probably won't
>>>> need it
>>>> anyway.
>>>>
>>>> I used 1 1/2" conduit to run 4 10 gauge conductors with two
>>>> sharp 90's
>>>> and one gradual 90 bend over 100 feet with no trouble. Also, 3
>>>> 12 gauge
>>>> solid conductors 125 feet through a 3/4" conduit with two
>>>> 90's. Didn't
>>>> use any pulling grease...
>>>>
>>>> John KE7JGB
>>>>
>>>> K4SAV wrote:
>>>>> After being disappointed in the direct burial method, I am
>>>>> planning on
>>>>> adding some conduit to access my low band receiving antennas.
>>>>> I have
>>>>> one section of conduit that is 500 feet. Can I do this with
>>>>> one pull,
>>>>> or will I be wishing a I had added an access box and broken
>>>>> the pull up
>>>>> into two parts? I have never pulled a 500 ft run before.
>>>>> Since it is
>>>>> unlikely that I will ever want to add another cable into this
>>>>> conduit, I
>>>>> was planning on using 1.5 inch conduit. The run will be
>>>>> straight except
>>>>> for a couple of very long curves and then the curve at the
>>>>> exit out of
>>>>> the ground at the ends. I need to pull one run of RG6 and one
>>>>> run of 16
>>>>> ga landscape lightning cable for dc.
>>>>>
>>>>> Before someone suggests sending the dc down the RG6 to eliminate a
>>>>> cable, the dc resistance of 635 ft of RG6 is about 22 ohms.
>>>>> (It's 625
>>>>> ft total to get to the operating position.) Besides the RG6
>>>>> already has
>>>>> dc controls signals on it as well as RF.
>>>>>
>>>>> Second question: What is a good method of putting the pull
>>>>> string in a
>>>>> conduit this long? I have put it there when building the
>>>>> conduit, but
>>>>> that is a pain. I have used an air compressor to blow a
>>>>> string tied to
>>>>> a rag thru the conduit, but never on a conduit this long. Is that
>>>>> likely to work?
>>>>>
>>>>> Jerry, K4SAV
>>>>> _______________________________________________
>>>>>
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> TowerTalk mailing list
>>>>> TowerTalk@contesting.com
>>>>> http://lists.contesting.com/mailman/listinfo/towertalk
>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>>>
>>>> ------------------------------
>>>>
>>>> _______________________________________________
>>>> TowerTalk mailing list
>>>> TowerTalk@contesting.com
>>>> http://lists.contesting.com/mailman/listinfo/towertalk
>>>>
>>>>
>>>> End of TowerTalk Digest, Vol 67, Issue 64
>>>> *****************************************
>>>>
>>>>
>>>
>>>
>>> _______________________________________________
>>>
>>>
>>>
>>> _______________________________________________
>>> TowerTalk mailing list
>>> TowerTalk@contesting.com
>>> http://lists.contesting.com/mailman/listinfo/towertalk
>>
>> - Jack Brindle, W6FB
>> ---------------------------------------------------------------------
>> --- ---------------------
>>
>>
>>
>
>
- Jack Brindle, W6FB
------------------------------------------------------------------------
---------------------
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|
