[PSUBS-MAILIST] An Idea for a PSUB Periscope

["Gary R. Boucher" <protek@shreve.net>]

     I have developed such a periscope for my sub.  I have not tested it 
however.  That is planned for later this summer or fall.  What I did was to 
take a lipstick camera which is about 5/8 inch in diameter and mount it in 
a acrylic tube about 1 inch ID.  I used a BW camera but color is a nice 
option.  I took a piece of maybe 3/4 inch acrylic and cut it slightly 
larger than the tube's OD.  I finished the end of the tube as flat as 
possible and "Welded" the flat piece on the end sanding the edges around 
the flat to taper the assembly slightly causing the end to be less blunt 
but still yielding a flat face that is optically okay for viewing.  The 
rear of the tube housing the camera has a machined PVC plug with two 
O-rings.  I potted the wires through the PVC with JB Weld after I broke 
them out into separate wires.
     Heat is a problem you may encounter.  Consider that you may be using 
the periscope in the summer in Louisiana.  It can be over 100 degrees in 
the shade.  Plus, you have direct sunlight hitting the tube for unlimited 
duration.  Clear is bad with too much heat absorption.  I experimented and 
researched what coating fairs best in sunlight and high heat.  I was 
surprised to find that metalic surfaces were not necessarily the best.  For 
example; stainless steel absorbs more heat than white paint.  Aluminum 
fairs little better.  White is cooler.  Look at the skycams that are used 
by TV stations.  They are all painted white.  So I painted the tube white 
with a urathane after sanding.
     Another problem related to heat is that when the camera is operated, 
it behaves like a resistor generating heat.  This internal heat has to be 
dissipated.  The thermal linkage between the camera and the acrylic tube 
(which is by nature a good thermal insulator) is critical.  I machined a 
hollow cylinder of aluminum that surrounds the camera and just fits into 
the inside of the acrylic tube.  This conducts the heat of the camera to a 
much broader interface along the inside of the tube.
     I bought a 4 inch color monitor assembly from Jameco (jameco.com) and 
incorporated it into a console that will be mounted directly in front of me 
in the sub.  If anyone shows any interest in all this, I will either send 
them photos or post a couple.  I don't like wasting download time for a lot 
of folks that don't want it.  I have no photos but can make some .JPG's in 
the next couple of days.  If interested send me an email to:

protek@shreve.net and I will try to send you an email back with photos.

Gary Boucher