[TowerTalk] Water in the conduit - a different idea

[K8RI on TT]

On 4/30/2011 3:51 PM, Clint Talmadge W5CPT wrote:

I'll vote with Al. Why worry?
This time of year my conduit or portions of it are under water.  IOW the 
water table is just below the surface and my sump pump in the basement 
gets a real work out.

Drain holes? They'd be letting water in, not out.

With the old run of conduit along the back of the house a good portion 
of it runs in the back fill sand.  That does have weep holes, not to 
keep water out of the conduit, but to keep it from running into the 
basement.  When I changed the system, I brought the conduit up outside 
the basement wall and into a Hoffman (NEMA) box mounted on the end 
plate, so the conduit comes into the house about 16 - 18" above grade. 
The only reason for me to keep water out of the conduit is to prevent it 
from freezing in the fall and winter.  I have no splices or junctions 
inside the conduit. All are in the junction boxes at the ends of the 
conduit.

73

Roger (K8RI)
> I am about to add a couple of antennas and the idea of burying conduit for
> the coax and control cables came up again.  The stories of water collecting
> made me think of how to avoid this.  What if I were to add a small fan to
> the box to which I am going to hang on the outside wall of the shack to
> which I am going to connect the conduit?  This fan would pressurize the
> ambient air which should eliminate any standing water in the system.  A
> small shroud to keep out the direct rain should be sufficient.  Small
> screened weep holes in the boxes at the tower base and the box for the
> phasing network for the verticals would allow any moisture in the
> pressurized air to escape.  The fan, being outside should not cause any
> objectionable noise.  I am thinking of something along the lines of a larger
> muffin fan which will run off house power fed out through the conduit
> installed through the wall.
>
>
>
> I have tried to come up with any negatives, but have not (yet).  Any ideas,
> positive or negative on this plan?
>
>
>
> Clint - W5CPT - West Kentucky
>
>
>
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