[TowerTalk] RMC 1000 Remote cable

[Joe Subich, W4TV]

If one wanted to avoid the rotary joints and "hose reels" it is 
possible to copy from what the broadcasters have been doing on 
TV news (microwave) vans for 30 years.  They use a "nycoil" which 
is simply a long, flexible conduit wrapped around the mast.  
The microwave masts generally extend 40' or so above the roof 
of the van ... the nycoil is about twice the length of the 
extending distance (75 to 100' for a 40' extension). 

When the mast is retracted, the nycoil coils around the base of 
the mast (on the roof of the truck) in a basket about five feet 
in diameter and two to three feet deep.  when the mast is 
extended, the coil spirals downward from an attachment point 
at the top.  Some truck builders add supports part way along 
the mast (generally a chain or piece of aircraft cable) to 
help reduce the stress at the top of the conduit.  

The one problem with "nycoil" for amateur use is that it is 
limited to 1.25" diameter.  However, I suspect the same thing 
could be done with non-metallic conduit (Sealtite) which is 
available up to two inches inside diameter.

73, 

    ... Joe Subich, W4TV 
        microHAM America, LLC. 
        www.microHAM-USA.com