[TowerTalk] Saddle clamps (muffler clamps)

[Jim Thomson]

Date: Fri, 30 Jun 2017 01:00:01 -0400
From: "Roger (K8RI) on TT" <K8RI-on-TowerTalk at tm.net>
To: towertalk at contesting.com
Subject: Re: [TowerTalk] Saddle clamps (muffler clamps)

<I'd stay away from muffler clamps and stick with real saddle clamps. 
<Check DXE. They have an excellent assortment.

<73, Roger (K8RI)

##  Muffler clamps, with their razor thin sheet metal saddles, are
designed for  exhaust systems, and thats  it.   IF you are using
em for plumbers delight construction, where the ele is attached to the
al plate..via  muffler clamps, you have to toss the saddles, and only use
the U bolts.  The sheet metal saddles, even galvanized, are a piss poor 
conductor of RF. This is the case where you want  the eles  bonded directly 
to the al plate.   Even then, you only have a tiny fraction of the curved 
ele actually touching the AL plate. 

## You have another issue with saddles, and thats the max thickness plate
you can get the threads of the U  bolts through.   Typ you can only use a max of
.1875 thick plate with the smaller muffler clamps + sheet metal saddles. The
larger muffler clamps + sheet metal saddles  will allow for aprx a max of a 
.25 thick plate.  Toss the saddles, and you can use a slightly thicker plate.

##  DXE has solved these issues with their  SAD  series saddle clamps.  SS  U bolts
with loads of thread.... really long, so they will fit any thickness plate, even .5 inch
with ease.   The textured  SOLID AL saddles are a real treat.  You require hardly any 
tq on the mating SS nuts  to get a tight connection. The solid AL saddles are really wide things
with loads of surface area.   IF you wanted a solid RF, bonded connection  from al ele  to al 
plate, you will easily achieve that via the al textured solid saddle, which are typ 1 inch wide. 

#  Then you end up with the lower 180 degs of each ele in direct contact with the solid al saddle,
and also being 1 inch wide,  now you have loads of surface area.   Muffler clamps + sheet metal
saddles just have a tendency to  crush ele tubing, and also booms.   They are also useless for
a mast.  The surface area of the edges of the sheet metal saddles is virtually nothing.   The portion of the
inside of the U bolt also has next to nothing for surface area.   This is why the DXE mast clamps are used,
which are just a pair of huge solid al saddles, but even wider, like  2- 2.5 inches..with loads of surface area. 

## Both m2  + JK ants  + optibeam will use back to back solid al saddles to mount the ele plates to the boom.
DXE also sells these types, but onky in 6 sizes. 
https://www.dxengineering.com/search/department/clamps-and-fasteners/product-line/dx-engineering-heavy-duty-saddle-clamps?autoview=SKU&N=4294950919&sortby=Default&sortorder=Ascending




https://www.dxengineering.com/search/department/clamps-and-fasteners/product-line/dx-engineering-saddle-clamps?autoview=SKU&N=4294950919&sortby=Default&sortorder=Ascending

https://www.dxengineering.com/search/department/clamps-and-fasteners/product-line/dx-engineering-super-duty-saddle-clamps?autoview=SKU&N=4294950919&sortby=Default&sortorder=Ascending

Jim   VE7RF