A Pair of Hands in an Old Pill Bottle
Chuck Lakaytis of
Lakaytis Broadcast Service told me about a favorite adaptor that
lives in a pill bottle.
Chuck learned this tip
from a seasoned AT&T engineer who happened to visit while Chuck
was trying to rack-mount some heavy equipment. In the shop, the
engineer grabbed a couple of 2-1/2-inch-long rack screws and, using a
hacksaw, cut off the heads. He then cut a slot in the end of each
rack screw, deep enough for a straight-blade screwdriver to fit. This
left him with a pair of headless rack screws that can serve as a
temporary mount for your heavy equipment.
Here’s how it works:
After you “locate” the equipment in the rack and note where the
top two permanent rack screws will go, insert your “adaptor”
screws into those holes. Then lift the equipment and hang it on the
headless rack screws while you secure the bottom with regular rack
screws. Then remove your temporary top screws and replace them with
regular rack screws.
To remove equipment,
just do the reverse. Take out the regular rack screws from the two
top holes and insert the headless screws; then remove the bottom
screws. The equipment will “hang” on the temporary top screws
until you remove it.
The PA911 and PA912,
part of the ETS PA-910 series, can be used as an iPhone adapter.
Courtesy Energy Transformation Systems
This extra set of hands
makes racking equipment easier; you won’t need a second person to
do the job. Store these little gems in a pill bottle so they’ll
always be handy. Thanks, Chuck, for sharing an ingenious idea.
* * *
classic Orban 4008 FM processors, frequent contributor Charles S.
“Buc” Fitch identified a functional equivalent for the original
and unidentified switch used in the “pilot on-off” and
It’s C&K Part
Number F2UEE, which is DigiKey part 401-1223. The matching push
button cap in “red” is C&K Part Number F0203, which is
DigiKey 401-1218 (www.digikey.com).
* * *
Belden’s Steve Lampen
drew my attention to the simple circuit in my July 3 column (to adapt
a balanced line microphone for iPhones). The one major problem Steve
finds with the circuit is that it unbalances the mic. If there is any
significant length of cable between the mic and the iPhone, this
could be a major source of noise and interference (EMI and RFI). The
solution is to maintain a balanced line, which will reject noise.
One way to avoid this
problem is to buy the iPhone adaptor from ETS (Energy Transformation
Systems) in Fremont, Calif. (www.etslan.com). It’s part of
their PA-910 series but contains the four-conductor plug mentioned in
Inside the XLR is an
actual balanced line transformer. This means that the mic and any
cable between the mic and the adaptor are balanced. The transformer
blocks DC, so you don’t need a blocking capacitor, and the
resistance of the winding of the transformer is more than enough to
load the iPhone input, so you don’t need the resistor either, when
you use this adaptor.
Also in that column was
a discussion about wires running in conduit. Steve points out those
NEC guidelines suggest a maximum conduit fill of 40 percent. This
permits cables to be added or removed, and makes the original bundle
easier to pull. Did you know that the maximum fill inside a conduit
is 40 percent? So how do you calculate the percentage of fill?
Belden offers a paper
called “The Adventures of Conduit
Phil,” which takes you through the calculations.
Steve is the
multimedia technology and product line manager (entertainment
products) for Belden.
* * *
I have found that many
engineers don’t like to throw things away, and I admit to being a
packrat to a point. But it would drive me crazy, as I made my way
through contract stations years ago, to see engineers toss bad
components in with the good ones. You’d have a drawer of parts,
half of which were useless. This made a troubleshooting job that much
more difficult, not knowing which part was good or bad.
Broadcast Engineer Paul
Sagi has a solution: Turn the useless parts into refrigerator
Paul picks up tiny
powerful magnets and a tube of super glue, attaching the magnet to
the IC, or even several interesting components. It makes for some fun
creations … unless you mind seeing reminders of past repairs every
time you open the refrigerator.
Workbench. You’ll help your fellow engineers and qualify for SBE
recertification credit. Send Workbench tips to firstname.lastname@example.org.
Fax to (603) 472-4944.
Author John Bisset
has spent 44 years in the broadcasting industry and is still
learning. He handles West Coast sales for the Telos Alliance. He is
SBE Certified and is a past recipient of the SBE’s Educator of the