[TowerTalk] Orion 2800

[Jim Thomson]

Date: Thu, 6 May 2010 12:08:54 -0400
From: "Mark Robinson" <markrob at mindspring.com>
Subject: [TowerTalk] Orion 2800

Will the Orion 2800 rotator fit through the side rails of the Rohn 45 or do 
you need to cut/bend the rails. If it doesn't I might get the top base plate 
BPL45G and fit it to a standard section 10 foot instead of getting the 
special flat top section 45AG4.



Mark N1UK

##  It should fit just fine.  I have 2 x OR-2800's  but don't use em on rohn-45G.    The distance  from
base of OR-2800 to flat plate is 9".    You may have to remove that 1/4-20  SS bolt... and remove the 
jumbo plate /mast clamp 1st.   Then install the OR-2800..1st.   Then stuff the plate /mast clamp in
after the fast... then  lower down onto mating splines.. then insert the 1/4-20  SS bolt back in...done. 

## Total height of that rotor is 15"... which may be a bit much to easily get into the sides of 45-g...
with out 1st removing the plate.   IMO... it would be far easier to remove the  1/4"-20  SS bolt...
and separate the 2 x halves... VS   removing 4 x  3/8"  bolts.. and just removing the jumbo 2 x piece clamp
from the oval plate. 

##  K7LXC is correct.  That stock OR-2800 jumbo 2 x piece mast clamp  will eventually slip on any mast..
and chew up any AL mast.  It will also rip the zinc off off any galvanized mast.  A far better replacement
is the mast clamps offered by K7NV... [ which are  custom  designed to fit the OR-2800].  They come in 2"
or 3"  variety.  He can also make em for odd ball mast diams... like  1.9"  or  2.875" or  2.5" etc, etc.  
K7LXC  also makes a OR-2800  replacement mast clamp.. all hot dip galvanized.... for 2"  mast only.
The small  K7NV Prop pitch I have  uses a similar  mast clamp... this one for a 2"  mast.    The 2"  mast
JUST squeaks into it.   Just barely tighten the 5 x bolts.. and the clamp  pinch's the 2"  mast  a full
350 degs... it will not budge.

The stock  OR-2800 mast clamp will handle any mast from 1.9"  to 3.125".  The problem is.. the teeth
have hardly any surface area..and will not bite into steel mast.  The 6 x bolts will also eventually loosen
up too.  The surfaces under both the head and nut of the 6 x 3/8"  bolts  is uneven at best, and does not
provide a good bearing surface.   My conclusion is.. a mast clamp can only be made for one mast diam only.

later............ Jim   VE7RF