On 9/23/2010 10:54 AM, Jim Thomson wrote:
> <snip>
> ## Much easier to just use .058" wall tubing, and just go up in 1/8" steps.
Agreed, if you are building one.
> My 20m els
> use 3/8" 1/2" 5/8" 3/4" 7/8" 1" 1.125" The 1.125" stuff is
> double wall. ZERO
> vortex shedding,
Actually the vortex shedding still exists, but without the major change
in diameter and short overlap the element is no longer subject to the
effects of the vortex shedding. IOW the swaged part has a very short
overlap that adds leverage to the element end without the damping or
support of "slip joints" where one section just slides inside the other.
The "slip joints" are just plain stronger and less prone to vibration.
> hurray, success at last. If ele truss lines are used, like on some 40m
> eles, and also booms, the truss line will kill the vortex shedding.
>
> ## Roger, how did you manage to strip out a SS hose clamp ?
Just a plain old Excelite nut driver...The small one that comes in a
set, not the larger Yellow handled ones.
> I have never see one strip
> ever. I only use Tridon SS hose clamps [ made in the usa] . I only use a
> nut driver, and crank em
> as tight as I can, and NEVER use a small socket wrench, open end wrench, etc.
Same here.
73
Roger (K8RI)
> Jim VE7RF
>
> Later... Jim VE7RF
>
>
>
>
>
> I've thought of trying this, but on a larger scale using rollers on
> larger tubing. The problem with swaging or working Aluminum is the
> stuff work hardens FAST. But at-any-rate, Those who have worked with
> lathes are probably familiar with the hand held knurling tool. It's
> hinged at the outer end, then back in a ways are two wheels on one side
> and one on the other. The piece to be knurled is held in and turned by
> the lathe. The knurling tool is placed over the tube with pressure
> applied to the handles, impressing the knurl into the Aluminum surface.
>
> If the rollers were replaced with smooth rollers the tool could be used
> to compress the swaged end of the element. Carefully done the entire
> swaged end could be smoothly compressed to fit snugly on the inner
> section. This would have to be done carefully and only a few thousandths
> at a time, but should work. OTOH it's going to a lot of work for a
> little gain. Me? I'd think it's worth it, but it's certainly not worth
> the expense of going out and purchasing a lathe and the tools to go with
> it.<:-))
>
>
>> Plus: as I noted here before, the clamps Hygain ships are no good. They are
>> cheapest of the cheap and will strip easily.
>> I will bet two cents there is no recognizable manufacturer name on the
>> clamps. (look)
>>
>> So: you want better clamps, so you can get more torque without stripping.
>> And you might want to double clamp just
>> because the swaging is bad.
>>
>> Maybe someone can comment about whether they've riveted the slit Hygain
>> swaged ends. I would think it wouldn't work as
>> well as normal telescoping tubing.
> I've had good luck with the Hy-gain joints and connectors, but the last
> ones I used were nearly 5 years ago. The looked a bit "tent like" made
> of SS strip, with a screw in the center. I've never stripped one of
> those but I sure have stripped a bunch of the SS hose clamps. I don't
> know what they use now that they've been "bought out".
> 73
>
> Roger (K8RI)
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