[TowerTalk] 90 degree coax bend atop a crankup tower

Sat Jun 6 17:48:40 EDT 2015

There is a tool (forgot the name) that will put a substantial flair 
...flare...in the ends of the EMT. Easy to make.  Actually, one of the 
tools used for flare fittings would suffice. Not as big a flare, but 
sufficient.  Easier to use, too!

73

Roger (K8RI)

On 6/6/2015 10:43 AM, Patrick Greenlee wrote:
> 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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-- 

73

Roger (K8RI)

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