[TowerTalk] Slipp-Nott

[Roger (K8RI) on TT]

On 12/20/2013 7:18 AM, John Becker wrote:
>> Tennadyne markets the Slipp-Nott.
> > Does anyone on the reflector have real world experience using this
> > item. Does it really work?
>>
>> 73
>> Dave
>> W1CTN
>
> I had one and I had a very bad experience with it. When the mast slips 
> in the rotor but not in the Slipp-Nott sleeve, the resulting forces 
> are transmitted through the Slipp-Nott brackets to the rotor U-bolts. 
> In my case, this caused the U-bolts to fail, leaving the antenna 
> totally free to rotate in the wind. The Slipp-Nott brackets were 
> totally mangled. On first glance the Slipp-Nott seems to be a good 
> idea, but when you analyze what is going on it is a bad design IMHO.


It's no different than pinning the antenna to the mast and points out 
the deficiencies of the particular rotator.  It's a good design if you 
don't want the antenna to slip.  OTOH many times having the antenna 
mounted rigidly to the mast may not be a good idea.

Although "they say" the ham series of rotators are rated for some good 
sized antennas, I see the entire series as being rather fragile and 
needing a wedge brake.  They were all I had when I put the array of a 
tribander, 7L C3i 6-meter Yagi, and the pair of 12L 144 and pair of 11L 
440 antennas up.
http://www.rogerhalstead.com/ham_files/Tower29.htm
   I went through several ham IVs and two HDR300s in less than 3 weeks 
while waiting for a PST61.

Except for small antennas (small tribander, or VHF antennas I will never 
use anything but a dual worm gear rotator again. The Ham series and HDR 
series are a good rotators for the money, but they turn far too easily 
with the brake off.
On a windy day, you have to release the brake and hit the power almost 
simultaneously and the brake needs to engage the instant the power is 
off or the antenna will spin beyond the limit switches, or stops. Yet 
there are circuits that delay the brake. These work fine on a calm day, 
but It tore the insides up on one of mine on a windy day because the 
antennas spun into the wind and were moving really fast when the brake 
engaged.

This is fine if you don't operate on windy days

I see nothing wrong with the slipp-nott design if used with enough 
rotator.  Unfortunately many rotators depend on the mast slipping to 
protect the rotator.

73,

Roger (K8RI)

>
> 73,
>
> John, K9MM
>
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