Field Equipment
Ideas
Every once in awhile someone
asks me what I use at the field to watch my airborne video. So, I thought
I would share what has worked well for me. Perhaps you will see something
that you like.
For the longest time
I carried a VHS camcorder, small 12V battery, XCam receiver, and a couple
of cables, in a cardboard box. When I got to the field, I unpacked it all,
attached some cables, and started recording. The camcorder's viewfinder doubled
as a realtime viewing monitor.
But a couple of years
ago I got tired of peering into the tiny viewfinder, so I added a battery
powered B/W TV monitor. At the same time, I decided that I needed to revamp
my luggage system. For sure, the cardboard box was getting a little worn
out.
I started searching
for a low cost carrying case. I looked at soft bags, backpacks, tool chests,
and just about everything in between. Nothing seemed to interest me, so I
searched for weeks. You can't imagine the thrilled looks a wife will offer
when you drag her from store to store in search of an elusive plastic
case.
Then I found it. I was
crawling around the attic one day and I noticed that I had saved the carrying
case to my Porter-Cable circular saw. It was a bit dusty, but it had never
been used. Sure, the saw had a few miles on it by this time, but even it
never left the garage. So, the storage case had seem useless to me.
Useless? Not any more.
The plastic case fit my equipment like a glove. Most folks that see it think
it was designed for my gear.
All I had to do was use a
cut-off wheel on my electric Dremel tool to make openings for the GelCell
battery and the XCam receiver. The little B/W monitor is framed by some resilient
foam that is glued around its base. When the lid is closed other foam bits
hold the monitor and battery in place. Even if I drop it, the contents are
protected.
By the way, the B/W
monitor has a story behind it too. I was at Longs Drug store one day (Xmas
1999) and they had a stack of 5" B/W TV's on sale for only $19.95. This tiny
set even had a AM/FM tuner, ran on AC, Alkaline batteries, or automotive
power.
It did not have external
A/V Jacks, but hey, that is what hacking is for. Within a couple of hours
I had reversed-engineered the video circuitry and added a toggle switch that
selects the TV tuner or external audio/video. I built up a cable that allowed
me to use the 12V GelCell for power (shared with the video Rx). It has worked
great since day one and the price was right.
I would offer the
instructions to hack the TV monitor, but stores are now full of cheap portable
TV's with AV jacks. I recently saw one on sale at K-Mart for $34.95. The
Target discount store chain also sells them for only $39.95. These are USA
stores, so those of you in other countries will have to just search around
for a low cost AV jack equipped TV set.
Wait, There's
More.
A few months ago I
purchased a 100mW transmitter (import type "tuna can" video system) and had
to accommodate its receiver and antenna. I thought about mounting it on the
carrying case, but I ended up doing something totally different.
The main issue is that
I wanted to be able to easily position the antenna. I had taken a spare XCam
Rx patch antenna and added a short piece of coax (RG-174) and SMA connector
to it. I found this antenna to work much better than the stock whip that
came with the new receiver. Now I had to find a way to deal with a dangling
patch antenna.
I decided to either
build or buy a tripod stand. At first I was using my aluminum camera tripod,
but I decided it was too nice for this application. In the end, I built my
own articulated Rx/Antenna stand.
The stand is nothing more
than $3 worth of PVC sprinkler pipe and fittings. I began by making a plastic
base for the receiver and patch antenna. I used pieces of 0.060" styrene
plastic. It cuts very easily if you score it with a knife and then snap it
apart. Pieces are glued together with plastic model cement. You can also
use wood (hobby plywood perhaps).
The patch antenna mounts
on an extension that extends from the top of the home built plastic base.
I wanted to keep the patch away from the other metal surfaces to ensure trouble
free reception. The photo offers the details.
The PVC stand is built
using 1/2" schedule 40 sprinkler pipe. This is commonly available
at most USA hardware stores, but is harder to find in other countries. If
you don't like the white color, then walk over to the electrical department
and buy 1/2 inch plastic electrical conduit instead. It is gray. By the way,
a ten foot piece will make several stands.
You will also need
three 1/2 inch "T" fittings and one
90º elbow.
Get the slip type, not the fittings that are threaded. Be sure to grab a
can of PVC cement while you are at it. The photos show the basic stand layout
-- I'll let you figure out the rest.
The
trick is to not use any glue on the horizontal end of the
90º elbow,
so that the pipe in it can be twisted for different angles. The pipe will
have a nice friction fit, so the Rx/Antenna assembly will stay put. I milled
a thru-slot and installed a keeper screw, so
90º travel
is allowed while preventing the Rx base from getting loose of the elbow.
This is really not necessary.
The above photo shows
the patch in a fully vertical position, which is useless for aerial applications
(but good for car/boat/robot mounted video cameras). The photo on the
right shows the patch at a typical angle that I might use at the field when
I fly my R/C heli or airplane.
The Rx/Antenna stand
can also mount onto the lid of the carrying case. If you look closely at
the photo on the left, the front legs are slipped into the latches of the
Porter-Cable case. The ground operator can simply rotate the entire case
to obtain the best picture, something that is easy to do while you peer into
the TV screen.
Lastly, the main vertical
pipe is NOT glued onto the "H" style floor stand. For storage, I pull the
pipe out of the floor stand (Rx/Antenna stays with the vertical pipe). The
separated base and antenna assemblies easily fit in a closet with all my
other hobby gear.
Hopefully you gleaned
some ideas from my experience. For sure, I may have given you a very good
reason to buy a new circular saw. |