[HomeBrew] Easy, Rugged, Inexpensive, Weatherproof project enclosures

[Philip, KO6BB]

Hi All,

Here is a "tip" that many of you may already know about, but which may also 
be new to many of you.  This article may be "overly long" for the 
experienced builder, but I went into detail for the neophyte home-brewer.

Often we have a need an enclosure for a project, and sometimes that 
enclosure may cost as much as the component parts did.  Especially if you 
have a well stocked junk-box!  Here is a simple method that works well for 
projects that have no external controls like switches or potentiometers 
(though an ingenious person could add a couple of those too).

There are MANY devices one may build that have few or no external controls. 
Things like "inline" amplifiers, Amplified or "Active" whip antennas for LF, 
small regulated power supplies (or in-line Voltage regulators to operate 
portable radios off 12 Volts), CAT interfaces to interface a modern radio to 
a computer RS-232 Port, etc.

White PVC pipe and fittings are both inexpensive and very rugged.  And, you 
don't need to buy a 10 or 20 foot section because home hardware stores like 
OSH etc. often sell "ends" that are perhaps 2-3 feet long for a reasonable 
price.  Enough to make a number of enclosures! (PVC pipe is something that 
marketers of wire antennas etc. discovered years ago) Here's How. . .

1.  Plan to build your project on a slender piece of PCB board or other 
project board. Something that will slip into a section of PVC irrigation 
pipe.  Obtain a short section of PVC pipe and TWO PVC end caps of the same 
size.

2.  Cut off a piece of pipe SLIGHTLY longer than the PCB board you plan to 
insert into it. The "extra" space inside the end caps will provide more than 
enough "slack" room for cable routing etc.

3.  IF it's an "inline" device such as an in-line amplifier, CAT interface, 
Voltage regulator etc., drill a hole in the center of each end cap, just 
large enough for the wire to snugly slip through.

4.  Build your project and attach the input/output leads to the PCB board. 
This assumes there are no plugs on the leads.  IF there are already plugs 
attached to the cables, feed the wire through the end-cap holes FIRST, then 
attach to the PCB board ;-)

5.  For in-line amplifiers it is entirely possible to just put short 
input/output leads on the PCB board and install either BNC or SO-239 
connectors on each end cap.  In this case make sure the leads are long 
enough to work with as you won't have a lot of elbow room to work.

A few tips.

1.  I like to use 1 3/4 inch Sched 40 pipe and fittings as it gives a fair 
amount of room for a good sized project (depending on length of the PCB 
board).  But larger sizes will accommodate larger boards while a smaller 
size may be ideal for a simple in-line Voltage regulator or a compact MIMIC 
amplifier.

2.  IF the unit will be used outdoors, allow it to "breath", or water WILL 
build up inside the unit.  It's best to install it vertically, seal the top 
end cap well, especially if a wire exits it, and drill a couple small 
"breath" holes in the bottom end cap. You CAN seal around the edges of the 
end caps with RTV compound, but I DO suggest that you DON'T glue the caps on 
with PCV cement.  You just might want to work on the unit sometime in the 
future.  A single small self tapping screw will hold each cap in place 
(drill pilot holes BEFORE installing circuit board :).

3.  When you've finished your project you 'may' want to use your computer 
and make a nice label for it along with the basic specs.  Such as "In-line 
Amplifier, 100KC to 30MC", "Input", "Power +12vdc", "Output".  The wide, 
clear tape such as is used in shipping packages is good for holding the 
label in place.

4.  This is also the time to draw a small schematic of the unit, roll it up 
and slide it INSIDE the pipe with the circuit board.  This for future 
reference in case you or somebody else ever needs to work on it. None of our 
memories are getting any better ;-)

using this procedure I have built MANY amplified whip antennas for LF.  What 
just brought it to mind today is that I'm presently building a CAT interface 
to connect my Kenwood TS-440S to the computer, and I needed a small case for 
it.  Then I spotted one of my "mini-whips" that is contained in PVC (and I 
have a number of fittings on hand).

73 de Phil,  KO6BB
DX begins at the noise floor!

Ten Meter CW Beacon KO6BB/B, 7 Watts 24/7 on 28.248MCs.
THE BEACONEER'S LAIR:   http://www.geocities.com/ko6bb/
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Merced, Central California,    37.3N  120.48W  CM97sh