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Re: [TowerTalk] Fw: Coax, conduit and toroids

To: "Marlon K. Schafer \(509-982-2181\)" <ooe@odessaoffice.com>, <towertalk@contesting.com>
Subject: Re: [TowerTalk] Fw: Coax, conduit and toroids
From: "Jim Hargrave" <w5ifp@gvtc.com>
Date: Thu, 28 Jun 2012 10:46:55 -0500
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
Try "Reply to all". works for me (Outlook)

    73s de Jim
       W5IFP


  > -----Original Message-----
  > From: towertalk-bounces@contesting.com
  > [mailto:towertalk-bounces@contesting.com]On Behalf Of Marlon K. Schafer
  > (509-982-2181)
  > Sent: Thursday, June 28, 2012 10:35 AM
  > To: towertalk@contesting.com
  > Subject: [TowerTalk] Fw: Coax, conduit and toroids
  >
  >
  > UG!  I sure wish this list responded to the list vs. the sender.
  >
  > Resending the below, to the right place this time....
  > marlon
  >
  >
  > ----- Original Message -----
  > From: "Marlon K. Schafer (509-982-2181)" <ooe@odessaoffice.com>
  > To: "K8RI" <K8RI-on-TowerTalk@tm.net>
  > Sent: Thursday, June 28, 2012 8:19 AM
  > Subject: Re: [TowerTalk] Coax, conduit and toroids
  >
  >
  > > According to Timesmicrowave the LMR 600 cable has a bend radius of 6".
  > >
  > >
  > http://www.google.com/url?sa=t&rct=j&q=&esrc=s&frm=1&source=web&;
  > cd=2&ved=0CGMQFjAB&url=http%3A%2F%2Fwww.timesmicrowave.com%2Fpro
  > ducts%2Flmr%2Fdownloads%2F28-31.pdf&ei=K3XsT_nxFIXKqgHH5pjVBQ&us
  > g=AFQjCNFPxXUVsHTlB1c558cLq3U2F9gvIQ&sig2=rXQk7FCCNeaaM1wS5LrmIA
  > >
  > > I think LMR 400 is 2 or 3".  I'd not be worried about using standard
  > > sweeps for the turns.
  > >
  > > Where it may get a bit tougher would be if you tried to use
  > an LB to enter
  > > a building.  Might need to look at a really big one or some other
  > > mechanism.
  > >
  > > marlon
  > >
  > > ----- Original Message -----
  > > From: "K8RI" <K8RI-on-TowerTalk@tm.net>
  > > To: <towertalk@contesting.com>
  > > Sent: Tuesday, June 26, 2012 5:57 PM
  > > Subject: Re: [TowerTalk] Coax, conduit and toroids
  > >
  > >
  > >> On 6/26/2012 8:30 PM, Rick Kiessig wrote:
  > >>> I'm interested in suggestions for how to best segment the
  > coax running
  > >>> between my shack and tower-mounted antenna. I'm thinking of
  > something
  > >>> like
  > >>> this: (1) from shack to the base of the tower through
  > conduit, tied to
  > >>> ground rod via lightning protector, (2) up the tower, (3)
  > from the top
  > >>> of
  > >>> the tower to the antenna, tied to #2 using a barrel connector and
  > >>> wrapped
  > >>> with weatherproof tape. The runs are fairly short, roughly
  > 20m from the
  > >>> shack to the base of the tower and 10m up the tower. Have I missed
  > >>> anything?
  > >>
  > >> Grounding to the tower at the top and bottom is a good idea.
  > >>
  > >>>
  > >>>
  > >>>
  > >>> I'm thinking of using LMR-600 for the first two segments
  > (seems easier
  > >>> to
  > >>> handle than Heliax),
  > >>
  > >> It is, but unless you are running QRO and/or UHF it's quite a bit of
  > >> overkill.
  > >>
  > >>>   and LMR-400UF for #3,
  > >>
  > >> From personal experience with both LMR 400 and 600 UF the UF versions
  > >> do not stand up well out in the elements.
  > >> I use Davis BuryFlex(TM). It's almost as flexible as the UF
  > cables and a
  > >> lot more durable.
  > >>
  > >>>   with UHF-style connectors for
  > >>
  > >> UHF connectors are difficult to find for LMR-600.  Davis was the only
  > >> company I found who would get them for me.  They were a clamp type.
  > >> Using UHF connectors and UF cable I'm going to assume you are talking
  > >> about feeding a tribander or something similar.
  > >>
  > >>> each. For my current setup, I ground the coax before it enters the
  > >>> shack.
  > >>> The new tower will be right next to the house, so the tower
  > ground and
  > >>> the
  > >>> before-entering-the-shack ground will be the same thing.
  > >>>
  > >>>
  > >>>
  > >>> What should I do to help ensure that the inside of the
  > conduit stays
  > >>> dry? Is
  > >>> applying some sort of weatherproof sealing compound to each
  > end enough?
  > >>>
  > >>>
  > >>
  > >> It's probably impossible to insure it'll stay dry, but a good start
  > >> would be http://www.rogerhalstead.com/ham_files/cablebox.htm
  > >> It's how I run the coax from both the shop and house to the
  > tower. Check
  > >> the 3rd and 4th photos from the top and the bottom two rows. This
  > >> presents a good way to terminate the coax out of the weather
  > as well as
  > >> entering the house without damaging concrete.  I really don't worry
  > >> about the conduit staying dry inside unless I have
  > connectors some where
  > >> inside the stuff.  IIRC I included an explanation of what I
  > did as well.
  > >>
  > >>
  > >>>
  > >>> I'm planning two coax runs and two control cable runs, in
  > two separate
  > >>> conduits, coax in one, control in the other. What's a reasonable
  > >>> diameter
  > >>> and turning radius for the conduit? The Times Microwave
  > >>> specifications/limits are one thing, but I also want to do
  > what I can to
  > >>> ease/simplify the process of pulling the coax through the
  > conduit once
  > >>> it
  > >>> gets installed.
  > >>
  > >> Use lots of cable pulling soap! Note the last photo in the
  > above link.
  > >> I also used two sweep 45s in place of a single 90.
  > >> Size wise make the conduit large enough to hold at least
  > twice as much
  > >> as you plan on putting in. That's for ease of pulling and unexpected
  > >> future events.
  > >> Also, don't forget to install a pull cable.
  > >>
  > >>>
  > >>>
  > >>>
  > >>> Are there any precautions I should take with regard to
  > running the coax
  > >>> or
  > >>> control lines near existing electrical wiring for the
  > house? I'm trying
  > >>> to
  > >>> avoid proximity as much as I can, but I'm wondering how far
  > I should go.
  > >>>
  > >>
  > >> I'd keep them at least 3 to 5 feet apart if possible. Farther in very
  > >> dry conditions, but often we have to make do with what we have.  I
  > >> actually have my control wiring and coax in the same conduits.
  > >>
  > >>>
  > >>>
  > >>> Is it a good idea to create a coil of coax in or near the
  > base of the
  > >>> tower,
  > >>> run through ferrite toroids? I do this at the base of my
  > vertical, but
  > >>> I'm
  > >>> not sure if it's as useful for a horizontal antenna.
  > >>
  > >> I have a one of these current chokes/baluns on each of my sloping
  > >> dipoles. On 75 I still had so much feedback that all the LEDs in the
  > >> shack would light by the time I reached a KW out let alone 1.5 KW. I
  > >> added a second choke in the 75 meter feed line at the tower and it
  > >> cleaned it up to where I can not detect any common mode
  > voltage making
  > >> it back to the shack.  If you need one, use one, if you
  > don't then save
  > >> your money.
  > >>>   I am planning to
  > >>> continue to use toroids at the shack end of the cable.
  > Should I also run
  > >>> the
  > >>> antenna and rotator control cables through toroids at both ends?
  > >>
  > >> 73
  > >>
  > >> Roger (K8RI)
  > >>
  > >>
  > >>
  > >> _______________________________________________
  > >>
  > >>
  > >>
  > >> _______________________________________________
  > >> TowerTalk mailing list
  > >> TowerTalk@contesting.com
  > >> http://lists.contesting.com/mailman/listinfo/towertalk
  > >
  >
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