[TowerTalk] 90 degree coax bend atop a crankup tower

[Patrick Greenlee]

At $22 each I'd just as soon Whip up a DIY solution.

First thing that comes to mind is a short length of galvanized steel 
tubing like EMT or similar, larger in ID than the OD of the coax. I'd 
drill a some holes in the tube in the bottom 1/4 of its length to accept 
some sheet metal screws and another hole say 3/8 of an inch from the end 
opposite the screws.  This last hole is sized to take a length of wire 
with which  the assembly is suspended  (I'd size the hole to take 3-4 
passes of the "seizing wire.")

With a grinder, file, or other means, dull (remover the sharp point) 
from the sheet metal screws so that when screwed into the aforementioned 
holes (don't have to be screwed in all the  way) room is left for the 
coax.  Tap the end with the screws with a hammer to make for a snug but 
not tight enough fit so as to deform the coax.
Roughen the coax jacket for good traction (60-80 grit) where it will 
contact the potting compound. Insert the coax, adjust the screws so they 
are not deforming the coax.  Pour in your catalyzed potting compound. 
You could use the polyester fiberglass type resin, or epoxy or the 
"Hobby Lobby"  grape casting stuff...

Howzit work?

The potting compound grips the roughened coax jacket.  The weight of the 
suspended coax pulls down on the coax inside the do-dad trying to pull 
the potting  compound and coax out the  bottom.  The screws are in 
shear, resisting the downward motion of the potting compound.  The ID of 
the EMT or whatever is less at the bottom of the do-dad than the top 
thanks to your  hammer taps so any attempt at downward motion of the 
potting compound  relative to the EMT results in radial  compression of 
the potting compound making it grip the coax tighter for better traction.

This is a first cut at a cheap coax hanger.  Please feel free to improve 
on it but please don't run the cost up a bunch.

If I could whip this out in 5 min off the top of my head then surely 
some of you smart guys could polish it up sufficiently to prep it for 
use. I think it should be doable for a couple bucks or so each. A few 
minutes of messing about with simple tools could make for a decent 
savings while making for a little shop fun.

No claim is made for having any beneficial effect on center conductor creep.

Patrick    N5G

On 6/5/2015 12:04 PM, Robert Harmon wrote:
> Me again.
> FWIW,  these are the cable strain relief grips I use.  One nice thing about these is you dont have to
> rull the cable through to attach as you do with the braided ones.
> These install right on the side of the cable easily and the sliding tapered clamp grips very well from the
> weight of the cable.  I have been using them for years and no problems.
> They are made by Hubbell I believe rather than Kellem.
>
> http://www.amazon.com/GARVIN-CHOKR1-WEDGE-CLAMP-ACSR/dp/B007886EDO <http://www.amazon.com/GARVIN-CHOKR1-WEDGE-CLAMP-ACSR/dp/B007886EDO>
>
> Bob
> K6UJ
>
>
>
>> On Jun 5, 2015, at 8:43 AM, Robert Harmon <k6uj at pacbell.net> wrote:
>>
>> I agree Rick.
>> I use the Kellems and they work great.
>> BTW,  I want order some more but I use the sliding clamp type not the braided ones.
>> Only see the braided ones now when I search on line.
>> They only make the braided ones now ?
>>
>> Bob
>> K6UJ
>>
>>
>>
>>
>>> On Jun 5, 2015, at 7:39 AM, Richard (Rick) Karlquist <richard at karlquist.com> wrote:
>>>
>>>
>>>
>>> On 6/5/2015 7:20 AM, Patrick Greenlee wrote:
>>> educe damage to the coax.
>>>> I haven't done/tried the following but solicit comments from those who
>>>> have:
>>>>
>>>> Use a large radius of curvature 90 degree section of conduit to increase
>>>> the area of contact between the coax and conduit.  Use an adhesive
>>>> (spray adhesive sold for attaching auto trim or other good adhesive) to
>>> why go to all this trouble when you can use a Kellems grip to hold
>>> the coax?
>>>
>>> Rick N6RK
>>> _______________________________________________
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