Sounds like you have your work cut out for you with that long pull but it is
doable if you plan ahead. First thing you need to do is suck a string into the
pipe using some light pull string ,Ideal make a product specifically for that
purpose with a 200# breaking strength ,a large Shopvac on one end of the pipe
sealed with a rag works good ,on the other end end use a light weight grocery
bag tied to the string and it should go no problem.Use the pull string to pull
in a larger rope 1/2' ,you can use a Kellum grip or just use half hitches on
the rope several feet back on the coax, it is a hell of a lot easier to pull
ALL the cables together to avoid twisting. The cables should be staggered when
you make the head and taped either with scotch or duct tape or both for
several feet. Use plenty of lube preferably Yellow 77 rather than the clear
lube and use lots of it particularly at the head as the cables enter the pipe
or dump a bunch into the pipe before you put the cables in ,probably need 2
gallons and lube the cables all the way during the pull. Its a lot easier to
lay all the cables on the ground rather than pulling off spools as you will
have less tangle. Two people at each end of the pull and use a steady
continuous pull till the cables come out the far end. The first two or three
feet of coax may be damaged due to the half hitches from the rope but a small
price to pay. If you can remove the first and last 90 degree bend it will make
it a lot easier with less drag ,45 degree elbows are a lot easier to pull even
if you have to use two of them to make a 90 degree turn once they are spaced
apart.Good luck and drop me an email if you have any more questions.
Andy N9TGR/EI6KG
From: "towertalk-request@contesting.com"
<towertalk-request@contesting.com>
To: towertalk@contesting.com
Sent: Saturday, September 3, 2016 8:47 AM
Subject: TowerTalk Digest, Vol 165, Issue 15
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Today's Topics:
1. Re: Tri-Ex LM 470 Sheaves (Roger (K8RI) on TT)
2. FW: UST Sheaves (Matt)
3. Alfa Spid rotors in Rohn 25 (n4jbk@comcast.net)
4. DIN to coax connector? (Jim Thomson)
5. Re: Pulling long length of 7/8 hardline in conduit (Grant Saviers)
----------------------------------------------------------------------
Message: 1
Date: Fri, 2 Sep 2016 22:11:58 -0400
From: "Roger (K8RI) on TT" <K8RI-on-TowerTalk@tm.net>
To: towertalk@contesting.com
Subject: Re: [TowerTalk] Tri-Ex LM 470 Sheaves
Message-ID: <95a0dc58-60f5-b51c-6b90-9e2ad521ddb9@tm.net>
Content-Type: text/plain; charset=utf-8; format=flowed
Check your local machine shops. They can probably make one for less
that the LM470 replacement cost.
Is the bushing shot? If so, the machinist can probably fit a sealed
bearing in place of the bushing.
73
Roger (K8RI)
On 9/2/2016 Friday 8:27 AM, Glen Turner wrote:
> Gentlemen;
>
> I realize this is a long shot, but I am in need of ONE sheave for my LM 470
> tower. They all appear to be the same size. Anybody have one laying around
> or know of a reasonable off the shelf source? Have got a call into Tash
> Towers.
>
> Glen W5IF
---
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Message: 2
Date: Fri, 2 Sep 2016 22:45:31 -0500
From: "Matt" <maflukey@gmail.com>
To: <towertalk@contesting.com>
Subject: [TowerTalk] FW: UST Sheaves
Message-ID: <013f01d20595$9f44fc10$ddcef430$@gmail.com>
Content-Type: text/plain; charset="us-ascii"
I have serviced the bearings in several of my crank-ups for the last 15
years by drilling a small hole in the side shield of the bearing just large
enough to allow insertion of a grease gun needle fitting - essentially a
hypodermic needle with a grease fitting on it. I think they sell them at
auto parts stores to refill things like CV joint grease boots without having
to disassemble the joint. Anyway, I just remove the pulley, pump the
bearing full of new grease till the old grease all squeezes out around the
perimeter of the side seals, clean up the mess, and reassemble the pulley.
In the case of older bearings that have become stiff, I flush them out
thoroughly in the parts washer first while working the races and they loosen
up pretty quick. The side seals are not 100% effective which allows solvent
to get inside and thin the grease. I also flush the bearings out in the
washer after drilling the needle hole to remove any metal shavings that may
fall to the inside of the seal. Just be sure to pump the bearing full of
grease after washing with solvent.
Hope this info is useful and good luck.
Matt
KM5VI
-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces@contesting.com] On Behalf Of Bob
K6UJ
Sent: Thursday, September 01, 2016 10:03 AM
To: towertalk@contesting.com
Subject: Re: [TowerTalk] UST Sheaves
That's interesting. With the correct selection, possibly lifetime
bearings..........
I would love to have sheave bearings with a little grease fitting so I could
grease them as I do the other grease fittings on the tower. We
discussed this
in the past but couldn't come up with anything. After replacing two sheaves
after they froze up I would like to improve the stock design if possible.
Bob
K6UJ
On 9/1/16 6:36 AM, charlie@thegallos.com wrote:
> <snip>
>> Will take them to my local machine shop and have new waterproof
>> sealed bearings pressed in as we discussed earlier.
> <snip>
>
> I sort of worry about the idea of any kind of ball/roller bearing in what
> is basically a static situation
>
> One of the big issues they found in cars was there was more damage done to
> a car's wheel bearings when shipping them on trains than actually running
> them. The vibrations/shock on the bearings in a fixed location caused all
> sorts of issues
>
> Believe it or not, in intermittent motion use (we aren't constantly
> cranking our towers up and down), Bronze bearings can be great BUT you
> have to keep them lubed!!
>
> What is often used today, and properly designed is probably the best is
> some of the exotic PLASTIC bearings. Going to one of the thin wall
> plastic bushings can give you GREATER load without creep, and will NEVER
> have to be lubed. Think of it as "reinforced Teflon", but some of the
> plastics are way better than that, all the way up to things like
> torlon/vespil etc (which are insanely expensive)
> If you are going to get a Sheave re-bushed, I'd look into some of the thin
> wall plastic bushings out there, and then bore the bronze to just fit the
> new bushing in there, and run that. Never need lube, picking the right
> product, and you'll never have an issue
> (Picking the right product = knowing the load on the bearing - so if you
> know the weight of the tower/antenna etc and the diameter of the
> bearing....)
> Look at igus.com (just first I found )
> Heck, depending on load, something as simple as acetal (aka delrin) or
> glass filled/reinforced acetal is probably enough (or even glass/Molly
> filled nylon)
>
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com
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>
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------------------------------
Message: 3
Date: Sat, 3 Sep 2016 05:02:58 +0000 (UTC)
From: n4jbk@comcast.net
To: towertalk@contesting.com
Subject: [TowerTalk] Alfa Spid rotors in Rohn 25
Message-ID:
<888979536.10955222.1472878978027.JavaMail.zimbra@comcast.net>
Content-Type: text/plain; charset=utf-8
Has anyone on this page used or known someone who has used an Alfa Spid rotor
on or more properly in a Rohn 25 tower? If so can you please let me know which
rotor and which top section you use? I need something more substantial than the
Yaesu G1000DXA. Since mother nature seems bent on stress testing all tall
things in my area I need something much better than this Yaesu thing. Thank you
for your help. 73, JOE N4JBK.
------------------------------
Message: 4
Date: Sat, 3 Sep 2016 03:42:34 -0700
From: "Jim Thomson" <jim.thom@telus.net>
To: <towertalk@contesting.com>
Subject: [TowerTalk] DIN to coax connector?
Message-ID: <1962303633154A9D9F95A8CA5E7FCF06@JimPC>
Content-Type: text/plain; charset="iso-8859-1"
Date: Fri, 2 Sep 2016 19:03:50 -0700
From: Bob K6UJ <k6uj@pacbell.net>
To: towertalk@contesting.com
Subject: Re: [TowerTalk] Message-ID:
<93b47c3c-0de9-264d-7e3d-5f9f7ad1139b@pacbell.net>
Gerald,
Thanks for the info !
Bob
K6UJ
## I got a bunch of 7-16 din chassis connectors from this outfit in peabody
mass, forget the name of the place,
well known though. Bought the din crimp type connectors for my 393 coax from
DAVIS RF...along with the crimping tool.
same crimping tool also does a bunch of other size coax cable.
## My make dins for my LMR-1200 DB cames from times microwave, they are clamp
type for the braid only, They used an expanding
ferrule thingy, on the inside of the hollow cu tubing center conductor.
## You can get 7-16 dins for everything from RG-174 / RG-58 /59...to rg 393,
rg-6, rg-213, lmr 400-500-600-900-1200-1800.
and every size heliax cable ever made.
## Nobody makes a din to uhf adaptor, only Type N to din. I used a din
male... to type N female adaptor... then a N male to uhf female...as
a quick way to attach test gear /MFJ-259 etc to stuff.
## They also make a 7-16 Din chassis connector..... that is unique, tapered
down at chassis end, such that the 4 x mounting holes are 1 inch square,
the exact same hole pattern as used on a type N female chassis connector......
and also a UHF chassis connector. The idea here of course, is a simple
method to easily convert any former type N female chassis conncetor to a
7-16 din, in minutes flat. Normal 7-16 din chassis female uses a 1.25
inch square flange with a bigger 4 x hole c-c spread than a type N / SO-239.
## and yes you can stuff 20 kw through a 7-16 din.
Jim VE7RF
------------------------------
Message: 5
Date: Sat, 3 Sep 2016 06:47:13 -0700
From: Grant Saviers <grants2@pacbell.net>
To: mskobier@charter.net, towertalk@contesting.com
Subject: Re: [TowerTalk] Pulling long length of 7/8 hardline in
conduit
Message-ID: <57CAD461.3060403@pacbell.net>
Content-Type: text/plain; charset=windows-1252; format=flowed
I think this is all great advice - I'd add a bit more
Use pull tape or braided rope so you don't put twist into the cables
when being pulled. Pull tape comes in various sizes and strengths,
something around 3/4" sounds right. 7/16" braid would be ok. Polyester
lines are fairly cheap on ebay.
Most important: install the biggest radius sweeps you can buy for the
hardline. At least 48", 60" might be available. If the larger ones are
only available sch 80 then the couplings might leave an edge to catch
the pull so check the ID match. I second the idea of a separate conduit
for other lines. With three x 3" conduit x 120' I have 2x LDF5 + 1x
LDF4 in one, 2 x LDF4 and 1x LDF5, and control wires in a third.
There are end bushings that chafe guard the open ends, use them as the
bare conduit edge easily strips insulation from wires. If you can
suspend the hardline reel above the feed-in point this is much better.
If the 7/8 is AVA5 you need to be *extremely* careful because the very
thin shield is easy to dent. LDF5 is much more forgiving. In either
case the number of large radius bends you have isn't a problem, check
the specs for minimum radius repeat bending life. I'm not a fan of
adding conduit to the full length, too many chances for a dent or glue
in the wrong place or dirt, especially with the length you are
installing. Feeding thru the sweeps is tricky.
One post from a cell installer said they refuse delivery of any AVA
reels shipped on their side since it is so easy to damage. Direct
burial of 7/8 and larger AVA sounds very risky to me unless in a full
sand bedding. You didn't mention the hardline you will install.
If you can borrow a capstan winch with a foot switch that is the most
controllable means to adjust the pull rate and tension. How the pros do
it. With a car or lawn tractor you have little feel for the tension.
Another choice is to rig some blocks or chain fall above the pull out
and pull in segments. If the tower is at the exit then this is easier.
I'd use a Kellems pull grip for the bundle. The pull Kellems have a
swivel that further reduces the chance for twisting, check ebay for used
ones.
A team of 4 or so is needed, talk it through and go slow with plenty of
lube.
Something I haven't tried but might help is to prelube the conduit with
a several mouse pulls both ways. Maybe a grouting sponge would be a
good mouse.
Good luck,
Grant KZ1W
On 9/2/2016 12:23 PM, Mike Smith VE9AA wrote:
> Having been an apprentice electrician in a former life for a few yrs, and
> having only a 160' run of 4" conduit with wires and hardline I can only
> offer
>
> some partial advice. Take it as offered.
>
>
>
> -Use more lube than you think you'll need. (lube it ever 30-40', not just
> the nose of the pull)
>
> -Tape everything really really really good.
>
> -Leave a flap of tape so when you unwrap the hardline from the rope it'll be
> easy (unless you plan on just cutting the hardline and rope)
>
> -If you can, pull all the wires at the same time.
>
> -Pull a pull string in with your hardline (instead of trying to put a mouse
> or fish tape through next)
>
> -Keep your hardline and 2nd pull string on spools if at all possible. (don't
> ask)
>
> -Put a 2nd conduit down for your other wires?
>
> -If you can see both ends, you can yell to the guy driving the lawn tractor
> (or otherwise controlling the pull) otherwise, handi-talki's are manadatory.
> I've seen pulls go bad
>
> and wires having to be replaced as something got tangled and wrecked (even
> on a manual pull) so communication is key.
>
> -When doing the pull it will be imperative to have someone feeding (pushing
> almost) the hardline in so it doesn't get gouged, scraped or bent, while
> someone else is pulling.
>
> Likely you're looking at a lawn tractor or car or something doing the pull.
>
>
>
> This sounds like a real doozy of a pull. Reminds me of an electrical job we
> did pulling 300+' of 3 x 0 cable, but we had a special electric motor with a
> huge reel in the electrical room to do the pull.
>
> GL !
>
>
>
> YMMV,
>
>
>
> I stand to be corrected.
>
>
>
> Mike VE9AA
>
>
>
> Mike, Coreen & Corey
>
> Keswick Ridge, NB
>
>
>
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>
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