| Author |
Message |
    
Docems
New member
Username: Docems
Post Number: 1
Registered: 10-2005
| | Posted on Saturday, April 15, 2006 - 2:47 pm: | 
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I am currently assembling a 50' rohn 25 tower to install a maco shooting star (moonraker 4) and mounting the Imax 2000 above that. My question for the tech is can this be done and not cause a problem with the beam and do I need the thrust bearing. Texas towers said since the tower ends with a 2 1/8th inch pipe and my mast goes through that I do not need the bearing and the rotor company said the rotor can support 400lbs max weight and wind load of 15 sq ft.
Any input would help greatly. |
Road_warrior
Senior Member
Username: Road_warrior
Post Number: 1341
Registered: 7-2004
| | Posted on Saturday, April 15, 2006 - 8:46 pm: |
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Always use a thrust bearing. The rotor will last much longer.
As for the Imax above the Shooting Star.
Side-mount it off your tower, instead of above
the beam or locate it somewhere else.
Others may have different opinions. Good Luck! |
Marconi
Advanced Member
Username: Marconi
Post Number: 646
Registered: 11-2001
| | Posted on Sunday, April 16, 2006 - 4:35 am: |
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I agree with RW. If the beam was a single polarity on the flat side, placing the Imax above the beam would likely work out with good results. With this type of setup the Imax is setting in a current node in the beam antenna and with the Shooting Star the Imax would be positioned at a voltage node of the vertical driven element and that is not so good. |
Tech833
Moderator
Username: Tech833
Post Number: 1312
Registered: 8-2002
| | Posted on Sunday, April 16, 2006 - 9:48 am: |
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In the case when using a Moonraker style antenna, or a yagi style mounted vertically, you do NOT want to run anything above the antenna because the A99 mounting pipe will act like a reflector in the middle of the antenna.
Best bet is to so as Road Warrior suggests. |
Dx431
Senior Member
Username: Dx431
Post Number: 1169
Registered: 2-2002
| | Posted on Sunday, April 16, 2006 - 10:04 am: |
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Yes, the Imax can be nounted above the Shooting Star without any illaffects. If it was me, I'd find another mounting point for the Imax. Either a seperate tower/pole or side mount it as Road_worrior suggested. |
Tech237
Moderator
Username: Tech237
Post Number: 282
Registered: 4-2004
| | Posted on Sunday, April 16, 2006 - 10:13 am: |
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I am not sure about the length of either of teh beams mentioned but I would not side mount the vertical.
Mount it in another location. Why? Well to side mount it from the tower it will need to be at least a few inches further from the tower than the turning radius of the beam, adn I suspect that's around 8ft.
In the past I have mounted verticals above beams (mainly horizontal ones) and generally have used a dual lenght of PVC pipe - that is two piece of pipe one inside the other. THis gives lightness, strenght and a non-conductive support.
Using this method a 10m vertical did survive several cyclones bakc in Australia. The tower was 45ft and teh base of teh vertical was at 55ft. |
Thehobo
Member
Username: Thehobo
Post Number: 75
Registered: 2-2004
| | Posted on Sunday, April 16, 2006 - 10:15 am: |
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as far as thrust bearings go, to me its up to the user!! i had a set of stacked 6 hornets on a 60 foot tower with a big stick above them for over 15 years?? this was on the oridgeable ham m rotor, and i used scheudal 80 1 1/2 inch pipe for the cross boom and pipe out of the rotor!! sold set up, the person that bought it, put new grease in it and he used the set up for 20 years, and the best part, the rotor held the hole load with no problem in all of that time?? oh yes, the rotor was mounted inside the tower!! so you can see my view on the thrust bearing?? and at the prices there getting for the stuff they sell anymore?? huummm,.. lol
thehobo
274150 am
monitor ch |
Road_warrior
Senior Member
Username: Road_warrior
Post Number: 1344
Registered: 7-2004
| | Posted on Sunday, April 16, 2006 - 11:35 am: |
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I have seen large rotors fall apart here in my
area from not using a Thrust Bearing.
Price: New rotor cost + New Beam cost = $$$
Some get lucky/some don't! Gotta ask yourself/
Do i feel lucky? |
Wally38
Member
Username: Wally38
Post Number: 95
Registered: 3-2005
| | Posted on Sunday, April 16, 2006 - 12:25 pm: |
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I had to mount my Antron 99 out on the garage. I had it on the house roof, but my shooting star on the tower didn't like it. Anytime I pointed the beam towards the Antron, the SWR's would go way up. You will love the shooting star and Antron setup. I know I do lol |
Docems
New member
Username: Docems
Post Number: 2
Registered: 10-2005
| | Posted on Monday, April 17, 2006 - 5:43 pm: |
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Thanks for all of the replies. Hopefully everything will be operational this week. |
