Springs, Boots and a Rodent Trap
I talk to engineers about submitting an idea of theirs to Workbench
I often hear this response: “Oh, everyone knows that tip!”
Add some tension to your microphone arm springs.
Judging from comments received about Frank Hertel’s submission on
differences between 75-and 50-ohm Type N connectors, though, quite a
few readers learned something. Glad we could enlighten you. So as we
start a new year, make it a point to share something you know with
other engineers by sending us a tip. Email firstname.lastname@example.org,
and include high-resolution pictures if you can.
number of years ago, when we couldn’t find a presenter for our
Society of Broadcast Engineers meeting, we just went around the room
discussing nuggets of engineering wisdom we’d picked up over the
years. I dare say no one left without a handful of good ideas. That’s
an idea in itself.
of good ideas, wouldn’t you like a dollar for every spring-loaded
microphone arm sold? There certainly are a lot of brands and styles
in the field using tension springs to hold the mics in position. Yes,
you can buy new springs when the originals eventually wear out — or you can add this tensioner using the existing weak springs (seen
in Fig. 1). A simple idea, and it works.
Jim Appleton is a retired chief engineer who sent in an excellent tip
— especially should you need to install a new phasor.
the power off, take the time to use a digital capacitance meter to
unhook and measure each capacitor. Then with a felt marker, print the
measured capacitor value right on it or next to it. This simple step
will help you check the actual measured value compared to the
manufacturer’s value. If something changes, you have a baseline
measurement from which to compare future readings. Another advantage
is that if you lose
capacitor and you have a junk box of replacements, you can choose a
replacement capacitor close to the original measurement.
Try polystyrene for insulator replacement.
a year, Jim also took the station down for overnight maintenance and
checked all capacitors, tightening all screws, nuts and bolts,
remaining careful not to over-tighten them. This is also a good time
to remove any and all critters and their nests. Scattering a few
mothballs in the bottom of each ATU and phasor cabinet will help ward
off snake and rodent trespassers.
you’re in the doghouses and phasor, use that felt marker to note
the position of coil clips on the inductors used in the networks.
Again, if a clip falls off, you’ll know where to reset it. Thanks,
Jim, for the great ideas.
* * *
love it when our television brothers and sisters weigh in on a
Barmore is with Dispatch Broadcast Group’s WTHR, Channel 13 in
Indianapolis. With respect to our tip about substituting PVC for
ceramic insulators in lower-power AM RF applications, Roberta writes
that plastic supply shops still sell polystyrene, which is a
better-behaved RF insulator than PVC. “Styrene” fittings, used
for drain lines, are also made of polystyrene.
for ceramic replacements, Roberta suggests checking with surplus
dealers or hamfests for real ceramic insulators. You can often find a
“will-fit,” especially for AM-band uses (as shown in Fig. 2),
where there's some “wiggle room.”
Tools announced the launch of RJ-45 Boots. Now shipping, the boots
are designed to work on standard RJ-45 and EZ-RJ-45 connectors. The
boots reduce the chances for broken or damaged connectors and locking
tabs, as well as wire stress. The boots are color-coded and can be
supplied in a variety of colors such as black, white, red, orange,
blue, gray, green, yellow and purple — seen in Fig. 3.
Colorful RJ-45 boots protect connectors.
pricing and information on Platinum Tools and its product line, visit
Workbench contributor Hal Schardin shared a couple of links on
the Pubtech forum, and thought our readers would benefit as well. The
links describe a resettable mousetrap, which can be really useful
around transmitter sites (and hopefully not needed around the
beauty of this device is that it uses commonly available parts: a
bucket, soft drink can or bottle, a coat hanger and some peanut
butter. To borrow a slogan from a famous infomercial, “You set it,
and forget it!” Rodents of any
type can wreak havoc at a transmitter site. The object of this trap
is to offer something better than wire to chew on. Placing this
resettable trap outside the building is effective, as described in a
YouTube clip you can find by searching “Bucket Mouse and Rat Trap”
(posted by user “maryannscupboards”).
variations of construction exist. Hal chose the cola can and a coat
hanger for wire to suspend the can. He also used two pieces of
3/4-inch PVC pipe to keep the can centered.
perhaps, the most humane trap, but then neither is a glue trap, and
I’ve seen those traps snare birds.
Thanks Hal for helping us
keep our sites rodent-free.
to Workbench. You’ll help your fellow engineers and qualify for SBE
recertification credit. Again, please send Workbench tips to
Fax to (603) 472-4944.
John Bisset has spent 44 years in the broadcasting industry and is
still learning. He is SBE certified and is a past recipient of the
SBE’s Educator of the Year Award.