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Bevrboy
New member
Username: Bevrboy
Post Number: 1
Registered: 4-2012
| | Posted on Friday, April 20, 2012 - 7:02 pm: | 
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ok i just picked up a 4 element Maco FREE i have been around CB sence 1993 roughly i know the answer to this question.. but im now on my own and looking for a cheap way out.. I DO NOT LIVE in a windy area in town the beam is only going 30-40ft the mastpipe is going to sit on a bearing.. can i use a nice TV rotor to get by with this. i see some HAM guys say yes you can get away with this then i see some cb guys say yes then i see NOWAY u will rip the gears out quick.. what do you guys think?? |
Starface
Senior Member
Username: Starface
Post Number: 3143
Registered: 1-2005
| | Posted on Saturday, April 21, 2012 - 11:46 pm: |
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You need to know what the square feet wind load area is of the antenna.
Once you know that you need to match it with a rotor of equal square feet wind load area or a bit higher to be safe that the rotor does not burn out. |
Tech833
Moderator
Username: Tech833
Post Number: 2154
Registered: 8-2002
| | Posted on Tuesday, April 24, 2012 - 10:28 am: |
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The small TV antenna rotors are designed to turn very lightweight, low windload antennas. Even a large TV antenna is too much for a TV antenna rotor.
I have seen a 3 element 10m yagi on a TV antenna rotor before. It didn't last long before it became a "weather vane". Even in a low-wind area, I wouldn;t put anything bigger than a 3 element horizontal-only yagi on a TV rotor. Bearing or not, that isn't the issue. All a bearing does is take the shearing forces off the rotor case. The issue here is braking and torque forces. Starting and stopping that antenna turning is the real rotor killer, not the wind.
A Ham IV would be prefect for your antenna. If you cannot afford a Ham IV rotor, then just put it up without a rotor, turn it by hand. Or, ignore us (what do we know?) and use a TV antenna rotor and let us know what happens. We'll do our best to keep the "I told you so" to a minimum.
Your radio 'Mythbuster' since 1998
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Press_man
Intermediate Member
Username: Press_man
Post Number: 487
Registered: 5-2008
| | Posted on Tuesday, April 24, 2012 - 10:43 am: |
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George is right especialy so if you mount it Vertical, Horizontal isn't quit as bad because the wind doesn't see to entire beam, but you are still dealing with beam weight and holding/braking power. If you mount horz you can kind of go cheap on the rotor. Contact Maco and get their input and specs on the beam. Or just ask the folks at Copper. They should know the specs on the rotors and beam.
73
Pressman/KC4ZWM
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Allagator
Advanced Member
Username: Allagator
Post Number: 861
Registered: 9-2002
| | Posted on Tuesday, April 24, 2012 - 7:59 pm: |
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i ran a small rotor for 5 years till we had a ice storm and the mast pipe froze in the tower and thats when the gears went south on the rotor !
if the beam is Horizontal it will work if you dont have alot of wind !!
CEF 115 / CEF HAM 290 /KC9OKX
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Tech237
Moderator
Username: Tech237
Post Number: 1569
Registered: 4-2004
| | Posted on Wednesday, April 25, 2012 - 8:31 am: |
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In short - Tech833 is correct. It will not last long. How do I know? Personal experience. A TV rotor I used lasted just 12 months in a low wind area turning a 4 element 2m yagi. which is a whole heap smaller and lighter than a 10/11m yagi.
To save yourself money ion the long run, buy a better rotorN NOW.
Tech237
N7AUS
God made me an athiest, who are you to question his wisdom?
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Press_man
Advanced Member
Username: Press_man
Post Number: 500
Registered: 5-2008
| | Posted on Monday, April 30, 2012 - 9:38 am: |
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So Bevr Boy, what was or is your final choice?
Inquiring minds want to know.
Pressman/KC4ZWM
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Roadking07
Junior Member
Username: Roadking07
Post Number: 14
Registered: 7-2011
| | Posted on Sunday, May 20, 2012 - 8:34 pm: |
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Beverboy,
I have the same beam you have so save yourself the aggrevation and go with an AR-40 it will totaly turn a 16 foot boom with no problem
Confidence Is The Feeling You Have Before You Know The Situation.
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