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Old June 24th 05, 05:01 PM
Bob B.
 
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Default Attic antenna: rotator upside-down work?

Hello...

Will an antenna rotator like a Radio Shack or Channel Master work if
hung upside-down from a roof beam, or should I try to come up with a
way to secure it to the attic floor?

I know rotators are designed to handle a certain weight, but I can't
guess at what they'd do with a "negative" weight...

The antenna I'm looking to rotate is a Channel Master 8-bay bowtie.
(CM4228)

Thanks,
-Bob-
N1GYL
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Old June 24th 05, 08:56 PM
Allodoxaphobia
 
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On Fri, 24 Jun 2005 11:01:20 -0400, Bob B wrote:

Will an antenna rotator like a Radio Shack or Channel Master work if
hung upside-down from a roof beam, or should I try to come up with a
way to secure it to the attic floor?

I know rotators are designed to handle a certain weight, but I can't
guess at what they'd do with a "negative" weight...


You've got a point about "negative" weight". Many rotators support
their load on the upper assy which, in turn, runs on a ball-bearing
loaded raceway. Probably a poor pratice to operate them upside down.

What you could look for is a rotator that permits the mast to run
clear through the whole works. These are often used in conjunction
with a separate load bearing supporting the weight of the mast below
the rotator. With a rotator such as this, you can mount the rotator
high in the rafters and run the mast _down_ from the _upright_ rotator.

It's a thought...

73
Jonesy
--
| Marvin L Jones | jonz | W3DHJ | linux
| Pueblo, Colorado | @ | Jonesy | OS/2 __
| | config.com | DM78rf SK
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Old June 24th 05, 11:56 PM
Chuck Olson
 
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"Bob B." wrote in message
...
Hello...

Will an antenna rotator like a Radio Shack or Channel Master work if
hung upside-down from a roof beam, or should I try to come up with a
way to secure it to the attic floor?


I know the closer you get to the roof, the smaller the permissible turning
radius, so maybe you need to cut through the attic floor and attach the
rotator to the side of a joist. There might be 6" more room that way.

73, Chuck W6PKP


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Old June 24th 05, 11:58 PM
Asimov
 
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"Bob B." bravely wrote to "All" (24 Jun 05 11:01:20)
--- on the heady topic of "Attic antenna: rotator upside-down work?"

BB From: Bob B.
BB Xref: aeinews rec.radio.amateur.antenna:33120

BB Hello...

BB Will an antenna rotator like a Radio Shack or Channel Master work if
BB hung upside-down from a roof beam, or should I try to come up with a
BB way to secure it to the attic floor?

BB I know rotators are designed to handle a certain weight, but I can't
BB guess at what they'd do with a "negative" weight...

BB The antenna I'm looking to rotate is a Channel Master 8-bay bowtie.
BB (CM4228)

BB Thanks,
BB -Bob-
BB N1GYL


I think it might work because rotators are rated for a large wind load
and hanging upside down doesn't even seem to come close to that.
However, I'd call the mfr first to ask for their recommendation
before doing it. I doubt any gears in the rotator depend on gravity to
stay in place. OTOH do you think fix mounting the rotator shaft and
having the antenna hanging off the mast fixture instead might work?

A*s*i*m*o*v

.... Thank Thor Friday Nears!

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Old June 27th 05, 06:06 AM
Leonard Kubiak
 
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How about buying a rotor manufactured in Austrailla......Problem
solved.,........





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Old June 27th 05, 08:29 AM
Blue Dawg
 
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Once you hang the antenna upside down, make yourself a daisywheel, like
on the dinner table. Then jack the daisy table upwards until it has
all of the weight of the antenna on it. Then you will not have any
weight hanging down from the rotor.

Where can a person take a look at this "Channel Master 8 bay bowtie
antenna?

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Old June 27th 05, 01:39 PM
Buck
 
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On Fri, 24 Jun 2005 11:01:20 -0400, Bob B. wrote:

Hello...

Will an antenna rotator like a Radio Shack or Channel Master work if
hung upside-down from a roof beam, or should I try to come up with a
way to secure it to the attic floor?

I know rotators are designed to handle a certain weight, but I can't
guess at what they'd do with a "negative" weight...

The antenna I'm looking to rotate is a Channel Master 8-bay bowtie.
(CM4228)

Thanks,
-Bob-
N1GYL



Chances are that the bearings are created for a right-side up force
and there will be insufficient bearings for upside down operation.

If your attic is like mine, you may consider getting a board to cross
a couple of rafters and mount the rotor on the floor from that.

Good luck.

73
N4PGW
Buck
--
73 for now
Buck
N4PGW
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Old June 27th 05, 03:49 PM
Bob B.
 
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Thanks for the responses, everyone! I'm going to explore the
possibility of attaching to a floor joist, though the suggestion of
getting the rotator from Australia wasn't half-bad!

btw, Blue Dawg,

Some links to this particular antenna:

sold he
http://www.solidsignal.com/prod_disp...=&PROD=ANC4228

UHF TV antenna comparison chart
(I like the fact that the CM4228 actually has "some" gain for VHF
9-13)
http://www.hdtvprimer.com/ANTENNAS/comparing.html


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Old March 24th 06, 03:38 PM posted to rec.radio.amateur.antenna
Buck
 
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Default Attic antenna: rotator upside-down work?



BB Will an antenna rotator like a Radio Shack or Channel Master work if
BB hung upside-down from a roof beam, or should I try to come up with a
BB way to secure it to the attic floor?



Do you have a break-down of the assembly of the rotor? If there are
no bearings when held upside down, you may damage the rotor by hanging
it that way.

Buck
--
73 for now
Buck
N4PGW
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Old March 24th 06, 04:13 PM posted to rec.radio.amateur.antenna
kd5sak
 
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Default Attic antenna: rotator upside-down work?


"Buck" wrote in message
...


BB Will an antenna rotator like a Radio Shack or Channel Master work if
BB hung upside-down from a roof beam, or should I try to come up with a
BB way to secure it to the attic floor?



Do you have a break-down of the assembly of the rotor? If there are
no bearings when held upside down, you may damage the rotor by hanging
it that way.

Buck
--

Don't know about some of the newer inexpensive TV type rotors, but my old
AR-40 has lubricated ball bearings running in a groove. Don't know if
running that upside down would
be a problem or not. I believe I'd work out an attic floor mount that would
allow it to operate in the normal orientation. If cost is not a priority,
however, running it upside down might make for an interesting experiment.

Harold
KD5SAK


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