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Message |
    
Sinker
Intermediate Member
Username: Sinker
Post Number: 297
Registered: 8-2005
| | Posted on Tuesday, December 06, 2005 - 12:20 pm: | 
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As you probably know by now I have had some issues with my station. I figure since I am going through it piece by piece I might as well go with a 4 element Beam Antenna with an Imax 2000 on top.
Tech291 put up a 4 element beam recently, any idea what brand etc.
The only 4 element Beam Antenna I see on Copper is shown Vertical - Can these also be installed flat / horizontally ???? Sorry if this sounds like a dumb question but I do not know. Does Copper sell a 4 element flat beam???
Think maybe a nice Maco 4 element Beam Antenna with the Imax 2000 on top would do fine for me.
Guess I also have to have something to turn the beam antenna correct? What is recommended?
How do you set up the coax so it doesn't spin around into a big knot or something.
What I really need is a step by step instruction on this.
Would 213 coax be good to use as I heard the LMR400 is to stiff?
My tower is 30' tall I run my Maco 5/8 at 40' because I added a 10' stinger but can't get away with that with the beams and Imax 2000 but may get away with an extra 5'. So will 35' be OK do you think.
Techs and Members Please give me sound advice on this as I need help, not sure where to start. Come on PLEASE....
Tim
CEF-634 |
Wildrat
Intermediate Member
Username: Wildrat
Post Number: 427
Registered: 12-2003
| | Posted on Tuesday, December 06, 2005 - 1:15 pm: |
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213 is fine, when I had a PDL2 I just used a rotator thing from them, I forgot the name used for them. It worked fine thru some harsh weather up there and it was reasonablty priced. If you go with a great big beam though you have to start getting into those real heavy duty ones. You should not have a problem with the coax twisting up, it does not keepturning in circles. It goes oneway and comes to a stop, thenyou switch it to comeback the other way. You just have enough coax up so it can makethe full travel.My pdl2 was only up about 40 feet,35 feet should be fine also.
Wildrat |
Road_warrior
Senior Member
Username: Road_warrior
Post Number: 1030
Registered: 7-2004
| | Posted on Tuesday, December 06, 2005 - 4:13 pm: |
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The Maco 4 can be mounted Verticle or Horz./
You will need a medium sized rotor or larger
to turn beam./ Your need a Thrust bearing./
Coax will get looped enough, so, beam can turn./
213 coax is fine./
Mount Beam at least 36ft./
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Wildrat
Intermediate Member
Username: Wildrat
Post Number: 429
Registered: 12-2003
| | Posted on Tuesday, December 06, 2005 - 4:29 pm: |
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Rotor, thats the word I could not remember. |
Sinker
Intermediate Member
Username: Sinker
Post Number: 298
Registered: 8-2005
| | Posted on Tuesday, December 06, 2005 - 4:31 pm: |
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OK - What is a Thrust Bearing |
Road_warrior
Senior Member
Username: Road_warrior
Post Number: 1031
Registered: 7-2004
| | Posted on Tuesday, December 06, 2005 - 5:07 pm: |
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Sinker,
What type of tower do you have? Whats the Top
section look like?
There is different ways to do this job.
One is to mount a rotor shelf INSIDE the top
section of your tower for rotor to bolt to.
A few feet above that mount a Thrust Bearing
shelf which Thrust Bearing gets mounted to.
The antenna pipe will go down through the top
of the tower, then through the mounted Thrust Bearing, then to rotor where mast bolts to.
The mast is centered in the Thrust bearing and
adjusted to keep most of the WEIGHT of the
antenna and mast OFF the rotor.
If you get high winds, get a good sized rotor
with a good braking system.
Beams have wind load specifications. Get a rotor
that will handle more than the specified wind load of the beam.
Do a web search for Rohn Tower for ideas.
Do a web search for Norms rotor service or anybody that sells rotors.
There's other ways to mount a beam also.
But, i have never tried them to comment.
Good Luck!
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Road_warrior
Senior Member
Username: Road_warrior
Post Number: 1032
Registered: 7-2004
| | Posted on Tuesday, December 06, 2005 - 5:12 pm: |
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Do a google search for (Thrust Bearing
for antenna rotors.)
JIM |
Tech808
Moderator
Username: Tech808
Post Number: 8575
Registered: 8-2002
| | Posted on Tuesday, December 06, 2005 - 5:22 pm: |
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Sinker,
A thrust bearing is what is used to support the the Mast and Antenna to keep the weight off of the rotor.
It is a LARGE Bearing mounted to a plate that fits and bolts inside of your tower that your mast pipe can run through and then you tighten the bolts in the bearing to support your mast pipe and antennas.
Below is just one example of a thrust bearing.
On our tower the Thrust Bearing is at about 40' from the ground and the Mast Pipe is all bolted together so there is a 1/2" gap between the bottom of the mast pipe and the rotor base.
And our rotor is mounted at Roof Level so we do not need to climb to the top or the tower should we have any rotor problems.
This allows us if needed to remove the rotor and the Mast pipe and antenna will stay in place if we need to work on or replace the rotor should any rotor problems occur.
Our thrust bearing supports roughly 65' of 1-1/2" mast pipe and the antenna.
Antenna Rotors are Designed to turn the antenna ONLY and NOT support the weight of your mast pipe and antennas.
Try doing a GOOGLE search for:
"Antenna Tower Thrust Bearing"
Lon
Tech808
CEF808
N9OSN
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Sinker
Intermediate Member
Username: Sinker
Post Number: 299
Registered: 8-2005
| | Posted on Tuesday, December 06, 2005 - 5:42 pm: |
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YIKES more stuff to learn. Hmmmmmmmm |
Tech291
Moderator
Username: Tech291
Post Number: 316
Registered: 11-2004
| | Posted on Tuesday, December 06, 2005 - 8:02 pm: |
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Hi Tim,
I'm not sure what brand the beam is I have up.The man I got it from was in advanced stages of altzhimers and could not recall where he got it.The only identifing markings on it were Cebik on one of the gamma straps,(do a web search for W4RNL,not sure if he marketed antennas or not).
You already got good info on the bearing,so I dont think I can add to that.
Your rg-213 will be plenty flexible for rotator use.An antenna rotator only makes 1 full turn from stop to stop,this is what keeps your cable from winding up on the mast.Most rotor controls are calibrated so that the stops(extremes)are to the north although some to the south.You being in Florida,I would imagine the majority of your 11 meter contacts will be west to north to east so a south calibrated rotator would be to your advantage.That would lessen wear and tear on the rotator and coax.You would bring the coax down the mast and anchor it about a foot above the tower,make a half loop with about 2 to 3 foot of coax then anchor it a foot below the top of the tower.That will provide the strain relief needed when the antenna turns.
If your going to use an Imax above the beam as opposed to the V-5000,mount the beam at 36'agl and the Imax just above it.That should give you about 3' of mast in the tower which would be the very minimum.
tech291
cef#291
kc8zpj
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Starface
Intermediate Member
Username: Starface
Post Number: 354
Registered: 1-2005
| | Posted on Tuesday, December 06, 2005 - 7:47 pm: |
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(Super Starface Music playing in the background)
No Need to fear Starface is here,,ahhh wait thats underdog!!
oh what the (BEEP) move over Superman and underdog!
cuz STARFACE Is Coming thru!!
Sinker just let me know when your ready to do this and I'll be back.
Till next time
Starface CEF#476
Southeast Net Control
Auburndale,FL |
