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

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

"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

"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!

How about buying a rotor manufactured in Austrailla......Problem
solved.,........

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

"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

"kd5sak" wrote in message
om...

"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
I don't think it will work right. There will be no force on the ball
bearings at all, they will just be floating. All the friction will show up
on whatever is on the other end of the shaft that keeps the unit from
falling apart.

Tam/WB2TT

"Tam/WB2TT" wrote in message
. ..

"kd5sak" wrote in message
om...

"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
I don't think it will work right. There will be no force on the ball
bearings at all, they will just be floating. All the friction will show up
on whatever is on the other end of the shaft that keeps the unit from
falling apart.

Tam/WB2TT



Caution, ancient history: In the early 1970's, I hung a rotor upside down
in an attic. It only had a 4-bay bowtie UHF TV antenna on it, but it was
rotated at least daily and never gave me a bit of trouble in about two
years.

No, I don't recall the brand but it was the kind with the wirewound resistor
and wiper for position information. Alliance may have been the company
that did it that way.

John
KD6VKW

On Friday, 24 Jun 2005 16:58:38 -500, "Asimov"
wrote:

"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!

I don't think it would work. The reason is that the bearings that
must turn will likely only be located on the bottom section expecting
the antenna weight feeding down in that direction. Twisting left and
right is a different problem from hanging upside down. The top of the
rotor may not have the kind of thrust support for any bearing that may
be there.

I can't say for sure whether or not it will work without actually
looking at the specific rotor's construction, but I can easily imagine
that the engineers would not have included an upside down option as it
would add significant cost to hundreds of thousands of rotors only to
be used by a dozen or so....

Rather than speculate, I would suggest contacting the manufacture of
the specific rotor in mind.


--
73 for now
Buck
N4PGW