[TowerTalk] AS25G plate

[Bruce Ferratt]

Richard-
Thanks for your email.
Instead of cutting a crossbar out of the tower and re-welding it,... I think 
I am going to go with cutting the accessory shelf down. Hard to believe that 
Rohn didn't design this shelf to slide down inside a regular section of 
tower,... only at the very top or between 10ft sections.
Thanks and 73
Bruce
K4BOF


>From: "RICHARD BOYD" <ke3q at msn.com>
>To: "Bruce Ferratt" <uglyatc at msn.com>
>Subject: Re: [TowerTalk] AS25G plate
>Date: Wed, 15 Mar 2006 09:23:34 -0500
>
>You're right that the gravity load of that heavy piece of aluminum will be 
>extraordinary!
>
>Otherwise, I'd say the downward load shouldn't be that much of a problem.  
>Many people, including professionals, prefer the tubular Rohn 25 top 
>section to the thrust bearing approach.  And you really need two thrust 
>bearings, one mounted on a second accessory plate, to keep the mast 
>straight when the rotators is taken in or out.
>
>But as to your question, yes, you can cut the Rohn plate.  Use a hacksaw 
>blade on the saw of your choice.  As to loss of strength, any time you 
>remove material you are, at a minimum, "changing" things and, probably, 
>weakening it.  The question, though, is whether sufficient strength 
>(material) remains.  And, your rotator, to some extent, once it's bolted in 
>place on the plate, is making up for some of the lost material.  The 
>rotator itself is metal too and becomes part of the mechanical structure 
>and picks up some loads.
>
>Frankly, except for an extraordinarily heavy mast, and if you put a large 
>load of antennas on the mast, the plate and rotator should be fine.
>
>If you want to go to the tubular Rohn top section, I have one to sell for 
>$50.  It would tend to make things easier I think.  And I have a couple 
>straight sections of 25 to sell too if you're interested.  Or upgrade the 
>whole thing to Rohn 45, 55, or 65, all of which I have to sell!
>
>73 - Rich, KE3Q
>   ----- Original Message -----
>   From: Bruce Ferratt<mailto:uglyatc at msn.com>
>   To: towertalk at contesting.com<mailto:towertalk at contesting.com>
>   Sent: Tuesday, March 14, 2006 10:59 PM
>   Subject: [TowerTalk] AS25G plate
>
>
>   Hello.
>   Can the Rohn AS25G accessory plate be cut easily and with what type of 
>saw?
>   Without sacrificing strength can a Yaesu rotor GS-450 be mounted on a 
>cut plate? I will be using a thrust bearing (TB3) for the vertical load.  
>Does the AS25G accommodate the Yaesu rotors without having to re-drill 
>mounting holes?
>   Thanks
>   Bruce
>   K4BOF
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