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Re: [TowerTalk] Pulling coax through PVC pipe

To: Patrick Greenlee <patrick_g@windstream.net>
Subject: Re: [TowerTalk] Pulling coax through PVC pipe
From: Dave Sublette <k4to.dave@gmail.com>
Reply-to: k4to@arrl.net
Date: Mon, 29 Jan 2018 10:01:04 -0500
List-post: <mailto:towertalk@contesting.com>
Patrick and all --

Patrick makes a very good point and I am planning to remove both the old
coax and the 14-2 wiring.  To clarify (again) there was never 117VAC on
that 14-2.  I used it because it is a large diameter wire and the run is
250 feet between the control box in the shack and the base of the tower.
There has never been more than 15 VDC on that cable.

I am planning to replace the 14-2 with a multipair control cable.  It will
have several pairs and I can double up if the voltage drop is too much.
This newer cable is smoother and should be easier to pull.

Now I must wait for good weather.

Thanks and 73,

Dave, K4TO

On Mon, Jan 29, 2018 at 8:40 AM, Patrick Greenlee <patrick_g@windstream.net>
wrote:

> Yes there are wire pulling lubricants available at your local big box
> store.  Use plenty, be lavish, it won't hurt your wires or conduit and it
> will make the job easier. You don't have a real tight fit (cables to ID of
> conduit) but you can cause yourself a problem if you make a bulge where you
> connect the old to the new if you use the old to pull the new.
>
> If it were me I would consider using the existing cable to pull a stout
> string which in turn would pull a stout rope or wire cable which would be
> used to pull the new cable. Another consideration is wether to leave the
> old 14-2 in the conduit or to remove it and put it back with the new coax.
> I recommend removing the 14-2 when removing the old coax and re-pulling it
> at the same time as the new coax. Why, you say?
>
> Pulling the coax into the conduit with 14-2 already in it has friction
> between the irregular 14-2 and the new coax that can cause problems pulling
> the new coax. When re-pulling the 14-2 at same time as coax there is no
> relative motion between the coax and 14-2, only between the coax plus 14-2
> vs the ID of the conduit which is much smoother than the 14-2.  Is this
> last bit of "finesse" required?  Maybe. You might be lucky and not need to
> use the above approach and have everything just go easy and smooth. Doesn't
> happen often for me, hence the "self defense" strategy.
>
> I recommend the Chinese finger grabbers to connect pulling ropes or wire
> cables to the coax and 14-2.
>
> Best of luck to you.
>
> Patrick        NJ5G
>
>
>
> On 1/27/2018 10:16 AM, Dave Sublette wrote:
>
>> Good morning,
>>
>> 28 years ago I buried a 1.5 inch schedule 40 PVC pipe in the ground and
>> ran some low loss coax and a three wire electrical control cable (14-2
>> house wiring cable).  The 14-2 is used to operate a remotely control
>> phasing box for my 80 meter four square.  The coax feeds either my 160
>> vertical or the 80M array.
>>
>> Well it’s time to replace the coax.  The PVC pipe is 250 feet long and in
>> a straight line(thankfully).  I suspect I will have to pull both cables
>> with the new cables tied to the end.  I’ve never done this before and could
>> use a little advice.  I googled but most of what I found started with empty
>> pipe and ran a “string mouse” through with a shopvac. When I installed the
>> cables initially, I laid them out on the ground and slipped the pipe over
>> them ten feet at a time. Fortunately, there is a fair amount of room left
>> in the pipe.  The two cables did not fill up the space entirely.
>>
>> My first question is if there is some sort of lubricant I should use to
>> reduce friction?
>>
>> That’s also my last question, but I know there must be several things to
>> consider I am betting that this group has the answers. I have a come-along,
>> a tractor, and a fair amount of tools.  I’m just not sure how to proceed.
>>
>> I am eager to see what you all have to say.
>>
>> Thanks.
>>
>> Dave, K4TO
>> _______________________________________________
>>
>>
>>
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