"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

Buck wrote:

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

How about mounting it rightside up but putting the mount in the top and
antenna on the bottom ?

Joe
WB2JQT

I got some 1 1/2" plastic pipe threaded on one end and threaded it into a
flange that had 4 mounting holes, the piece of pipe was about 12" long, and
screwed it to the floor in my attic and mounted a "RADIO SHACK" rotator and
a small mast to the top and mounted a 2 ele 2m quad. Quad and rotator works
great!

best 73's - de Howard W3CQH

"dada" wrote in message
...


Buck wrote:

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

How about mounting it rightside up but putting the mount in the top and
antenna on the bottom ?

Joe
WB2JQT

dada wrote:

Buck wrote:


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


How about mounting it rightside up but putting the mount in the top and
antenna on the bottom ?

Joe
WB2JQT

The same problem. The thrust bearing is setup to support the upper
section of the rotor pressing on the bearing pressing on the lower
section of the rotor. (long complex sentence).

Dave WD9BDZ

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

My oppinion would be: that while it May, or May
Not work (depending on the bearings in it), The
MAIN consideration, tho, as I see it would be
WATER in the Control Cable connections, when a
Rotor is upside down (obviously NOT a factor ,when
mounted under a cover, roof, ect)! Probably will
work fine!
just DONT try this if EXPOSED to the Weather! Jim
NN7K

On Sat, 15 Jul 2006 02:39:54 GMT, Jim - NN7K
wrote:




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

My oppinion would be: that while it May, or May
Not work (depending on the bearings in it), The
MAIN consideration, tho, as I see it would be
WATER in the Control Cable connections, when a
Rotor is upside down (obviously NOT a factor ,when
mounted under a cover, roof, ect)! Probably will
work fine!
just DONT try this if EXPOSED to the Weather! Jim
NN7K


Rotors are made for use on tall towers. There quickly reaches a point
in which rain rises as well as falls. Rotors have to be made water
safe from any angle so that shouldn't be an issue.
--
73 for now
Buck
N4PGW

"dada" wrote in message
...

How about mounting it rightside up but putting the mount in the top and
antenna on the bottom ?

Joe
WB2JQT


The only problem is that the direction an postions on the controller will be
reversed.
For personal use probably no problem.

Sincerely,

Gregroy D. MELLOTT

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)

I did it years ago with a 4-bay bowtie -- lighter, obviously, than your
8-bay, but I had not a bit of trouble over several years.

I was at Ft. Meade, MD, near Baltimore. I connected two antennas in the
attic -- close, so they'd interact -- one VHF aimed toward DC and one UHF
hanging upside down on a rotor. I rotated for UHF as needed, and used the
UHF antenna to cancel ghosts on VHF. The whole stupid thing was a success
the first time -- entirely by accident. I had envisioned a WHO-O-O-LE lot
of trial-and-error, but none was needed. And the rotor did not die in about
two years of daily use.