|With the holidays coming up,
our intrepid author offers a cornucopia of useful suggestions
When you work on a transmitter, especially a tube model, you’ll
encounter very fine gray-black dirt particles. After my days working at
transmitter sites, my wife Paula often said, “You smell like a little
transmitter.” The first task was to wash my hands, but they often stayed
black because of dirt embedded in the skin. Paula wouldn’t let me sit
down to eat with dirty hands.
Fig. 1: Use a nylon brush to remove dirt from under fingernails.
For stubborn dirt, I use a scrub brush to force dirt particles out from
under my fingernails and skin wherever needed. Also, I found scrubbing
my hands while showering with a good hair soap, like Head & Shoulders
shampoo, worked well. Paula’s father was a furnace repairman; she knew a
few of these tricks even before meeting me.
Here’s another basic tip: Use a plastic stool for jobs that would
otherwise require squatting. It can also be used as a step to reach up
just beyond your normal height. A stool of this type costs less than $4.
I carried one in my service van for the last 15 years on the job. It
For kneeling, use a pad to prevent knee problems. You’ve seen them:
inch-thick rubber or foam sheets that are about 8 by 15 inches. These
are as inexpensive as $3. For continuous use on a project that requires
more movement, use knee pads that strap to your legs. The construction
trade uses them. You can too.
Fig. 2: A plastic stool prevents sore knees.
An Xcelite 2210 tool gives a perfect crimp every time on solderless
terminals of three sizes. I’ve found the reliability to be 99.99 percent
during the course of 20 years of frequent use.
With traditional crimpers, you can squeeze as hard or as little as you
like. That’s a problem because the integrity is not always as good as
you’d want. Best to pull on a terminal after crimping to make sure it is
tight and will stay on the wire. The 2210 is a hand-operated machine,
which won’t release until it has gone through a complete crimping cycle.
They are a single action that crimps terminals in two places. Look for
what is now called the Draper Expert 35574 Ratchet-Action Terminal
Crimping Tool; I recently saw it for sale on Amazon for $33.54 plus
shipping. Voilamart appears to have the same tool for as little as
Fig. 3: A professional-grade wire terminal crimper
ABOUT THAT CIRCUIT BREAKER
Using a shorted
120 VAC power cord as a test tool to locate a circuit breaker is a bad
idea! For starters, the life of the circuit breaker will likely be
shortened by such an act.
If you do the math, a 100 foot long 15 ampere circuit will draw 237 peak
surge amperes when shorted. A 50 foot 20 ampere circuit could hit 756
amperes of surge current and 90,720 watts on a circuit designed to
deliver a maximum of 2400 watts. Ouch, that’s 38 times the rated
current! It’s hard on the wiring as well. Sure, the circuit
breaker will trip quickly, but wire nut splices and other power outlets
along the way could suffer as well.
Fig. 4: Use circuit breaker finding tools to trace wiring.
There are test instruments to locate breakers and associated wiring. The
one I have is an Ideal brand 61-532 Circuit Breaker Finder. It consists
of a low-power transmitter, which plugs into a power outlet and appears
to operate below the AM broadcast band. A hand-held probe is used
to safely find the signal when held near a wire or circuit breaker. New,
the pair are as little as $75, but $25 can get you the set on eBay.
Cheap at twice the price!
BNC connectors can become troublesome with age. I ran into one
on the end of a test lead to my Sencore Z Meter. The shield portion of
the connector was not reliable. It wasn’t the connector installation but
the two connector body parts that rotate on each other. There is the
main body that connects to the cable end and then there is the part that
grabs and locks onto a mating connector with a quarter-turn twist.
You would think metal to metal contact would be good enough. Well, with
years of dirt and corrosion, the two body parts can become electrically
isolated from each other. I use Caig Labs D100 DeoxIT D100L-2DB to clean
and preserve contacts.
Fig. 5: Use Caig DeoxIT on a BNC connector.
But that didn’t work in a recent case. Instead, replacing the connector
solved the problem. I often use DeoxIT on the center pins of coaxial
connectors to preserve contact integrity. Use a brush applicator
rather, than a spray. That way, you can put as little or as much as
necessary to get the job done.
I ran into a
problem on a C-Band satellite dish years ago where only some of the
transponders came through. On a whim, I replaced two right-angle N
adapters at the low-noise amplifier with a short N-to-N jumper cable.
Apparently, the spacing between the two 90-degree adapters was such that
it formed a trap of sorts to notch out one or more transponder
frequencies. Remember, we are talking 4 GHz. The satellite dish
installer must have thought it was a clever idea to install this “U”
connector arrangement to join a sky-pointing LNA connector to a
half-inch coaxial cable. While we don’t see many LNAs anymore, the
lesson is that bad/strange things can happen when transporting microwave
RF frequencies. The potential for problems is much less at lower
Your tool kit
should include a ground fault circuit interrupter tester, even if you
are not an electrician. The GFCI shown in Fig. 6 is a hardware store
item that typically sells for less than $10. This one has lights to
identify five problems, in a circuit, plus a pushbutton to test GFCI-protected
outlets. Best to use it whenever there is a question about 120 VAC
wiring at a site.
First, you’ll determine if power is available at an outlet, you might
find the hot and neutral conductors are reversed or the ground is
missing. Now we are talking dangerous. Check the power extension cords
you carry. They could be wired incorrectly or have a broken connection.
Use tools with three-wire power cables whenever they are not battery
powered. A man in my area was electrocuted a few years ago while using
an electric drill on a boat dock. The drill was metal-cased and someone
had cheated the power cord plug by clipping the ground pin off. He was
standing in water and would have been safe if the ground was present or
if the power outlet was GFCI-protected. Remember, GFCI outlets are
required under the National Electrical Code whenever there is water
nearby. Transmitter sites are a good place for GFCI-protected outlets.
Sure, it is dry inside, but you might be working outside at the base of
a tower where the ground is wet. Be safe rather than sorry.
Fig. 6: A power tester and mirror for your kit.
A dental mirror is also shown in Fig. 6. It is great for looking around
corners. Note that this tool is plastic cased to avoid the possibility
of shorting a circuit to ground conducting power to your hand. Think
safety! Use the right tools to save yourself time and trouble. It
makes perfect sense.
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Mark Persons, WØMH, is an SBE Certified Professional Broadcast Engineer,
recently retired after more than 40 years in business. His website is www.mwpersons.com.