6/20/2012 12:01 PM
“Time and tide — and now technology —
wait for no one.” Gazing back through the 20-20 rear-view mirror of life, our
industry looks more and more like a prime example of this cliché.
A recent multi-party exchange amongst confreres about a
pending 50 kW AM installation — in which the entire RF plant fits in a cell
site-sized concrete manufactured building — spawned a flurry of comments about
“the good olde days.”
Ah yes, back when dinosaurs ruled
the earth, transmitters were BIG. You could walk through them, stand up while
inspecting or maintaining, use wrenches and other hand-size tools to fix them,
heat the building in deepest winter with just the waste heat … near tech
These BIG rigs required 24/7 love and
attention; and real buildings surrounded them … structures with comfortable
furniture, nice bathrooms (occasionally with a shower), a kitchen and even an
odd occasional bunkroom!
We all agreed that the good
olde days are never coming back and none
of us wants them to come back; yet there is something fuzzy and comforting
in memories of a time when our immediate attention and knowledge were critical
to staying on the air and keeping those BIG machines running.
and cost pressures precipitated changes, many of which have been annotated in
my Milestone columns
. Remote control
of transmitter sites was probably the first where engineers’ expertise was
moved to the studio, and the remote
was the Waldo for those tech talents.
early facility conversions generated interesting technical challenges. For one:
How to remotely control transmitters never designed for this function?
My good friend Paul Gregg reminded me that many conversions used
motor-driven circuit-breaker operators to motivate the circuit-breaker switches
on some World War II-era gear. That is how major subsections were turned on and
Although motor-driven CB operators are seldom used today,
the most ordinary motor drive attached to a CB now is a “re-setter.” I actually
have a BIG CB re-setter on my shop shelf. If you spend 50 years in this
business, you’re bound to pick up odd things.
Although the accompanying pictures may appear to
show some sort of medieval torture device, this gismo actually is a
motor-driven, BIG circuit-breaker re-setter.
the main or a very BIG CB has a nuisance trip caused by line surges or back
surges from an abrupt or bouncing power disconnect. Or maybe you just want to
have really close protection on your very expensive system. Anyway you don’t
want to drive all the way out there to re-set the circuit breaker, so you have
this motor-driven BIG CB re-setter.
How does it work? To
allow the CB free travel to trip, you place an attachment on the handle (first
pic) such that there is no “drive” tension on the CB handle. When over current
or a thermal trip occurs, it can move to the tripped position.
The motor is 120 volts, so obviously you would get this power
from an UPS if the re-setter was on the building or system main.
The rotary motion of the device picks up the CB handle and
moves it through its “off” and then “on” positions, resetting it (see the
A standard option (which can be field
installed) is an aux switch on these big CBs. Those contacts stop the motor and
drive system in the “trippable” position.
not elegant, not beautiful (actually ugly). But it does the job well.
The last one of these re-setters I specified was on a rig in a
miserable station located on an island. To reach it, the chief engineer had to
drive for an hour, and then row out.
Later, the CE had
the audacity or affection to call me in the middle of the night (forgetting the
time change) to tell me how happy he was the first time he had to reset the CB.
He was able to do so remotely, getting his station back on the air using his
telephone on the night stand — rather than getting up, driving an hour, rowing
in the dark and walking up the hill to reset the CB. So these units do have
their place in broadcasting.
(I guess if you turn these
pictures upside down, this beastie does look like a medieval torture device.)