Lifting a 20 foot 200 lb chrome molly mast with a 5 el 20 and a 2 el 40 is
not easy to "lift up a few feet" either.
chet N6zo
----- Original Message -----
From: "Doug Renwick" <ve5ra@sasktel.net>
To: <towertalk@contesting.com>
Sent: Monday, October 25, 2004 5:08 PM
Subject: Re: [TowerTalk] Re: Thrust Bearing Usage
> Here we go again...making assumptions. When you are using an
> undersized thrust bearing I can see your point Kelly. Not
> everyone is using a CDE (MFJ) Ham or Tailtwister rotor.
> Have you ever seen the bearing inside a HDR-300 rotor?
> It is dinky and I feel not designed to take a lot of weight...so
> the thrust bearing takes most if not all the weight. Different
> rotor/mast/antenna combinations require different designs.
> BTW I place a saddle clamp on top of the thrust bearing for
> safety purposes just in case I have a senior's moment.
>
> Doug
>
> ve4xt@mts.net wrote:
>
> > As much as it pains me to see this thread revived so
> > quickly after it died out the last time (this is well covered
> > in the archives)...
> >
> > I'm in the bear-the-weight-on-the-rotator camp.
> >
> > As one has suggested, many bearings have screws
> > designed only to centre the mast. Also, as far as even
> > the HyGain CD45II is concerned, there are more
> > bearings on more races in rotators than in typical thrust
> > bearings.
> >
> > If this makes rotator failure more frequent, so be it.
> > Think about it: if I have to change out the rotator, that's a
> > fairly simple procedure, even on one that's bearing
> > weight. If I have to change out the thrust bearing, I have
> > to make one end of the mast pass through the thrust
> > bearing. I'd rather lift the antenna-mast assembly the
> > 1/8-inch or so it will take to remove the weight from the
> > rotator than the two feet or more it will take to have the
> > lower end of the mast come out of the tower... From that
> > standpoint, I'd want to make sure the thrust bearing
> > lasts as long as possible. No matter how you cut it,
> > replacing a thrust bearing is a big job, perhaps even
> > mandating lowering all the antennas to the ground.
> >
> > 73, kelly
> > ve4xt
>
>
> --
> Doug Renwick VA5DX
> PO Box 50, Clavet, Saskatchewan, Canada S0K 0Y0
> VE5RA@sasktel.net
> First VE5 9BDXCC
> What profit it a ham if he gains all the awards yet forfeits his soul?
> I'll run the race and I will never be the same again.
>
> _______________________________________________
>
> See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless
Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any
questions and ask for Sherman, W2FLA.
>
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_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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