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Topic: the situation is worse than you thought
Replies: 10   Last Post: May 4, 2013 11:58 AM

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Jeff Liebermann

Posts: 13
Registered: 9/13/07
Re: the situation is worse than you thought
Posted: May 1, 2013 10:10 PM
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On Wed, 1 May 2013 17:50:45 -0400, "Tom Del Rosso"
<tomd_u1@verizon.net.invalid> wrote:

>
>Artemus wrote:

>> >
>> The same thing was done with the hand held microphones of CB
>> (and probably other) radios in the 70's. A metal plate was added to
>> increase the "heft" and assumed quality of the mike.

>
>It probably also prevented the coiled cord from springing the mic out of its
>holder when you put it down.


It's much more complexicated than that and it didn't originate with
CB. Way back in the late 1950's and early 1960's, there was a TV show
called California CHP with Broderick Crawford. (Yes, I'm showing my
age).
<http://www.youtube.com/watch?v=2l3jYfV8BtQ>
To be seen talking on the radio, a new innovation in the 1950's, he
was usually standing outside his Buick, talking into the Motorola
microphone. When done, he would often would throw the microphone into
the vehicle, where it would presumably land on the seat. That's
because the "persuader" microphone of the era was made out of heavy
cast zinc, had a rather large heavy carbon microphone element, and
included a really heavy duty coil cord, more suitable for an electric
power tool than a microphone. It was good, reliable, and survivable.

Enter the 1970's and Motorola decided that smaller and lighter radios
needed smaller and lighter microphones. Never mind that there was no
correspondent shrinkage in the size of the users. The new mic was
made from light plastic and had a light dynamic mic element. The
heavy duty coil cord didn't change. The result was when the typical
Broderick Crawford wannabe would release the microphone, the tension
in the coil cord spring would launch the mic towards the pre safety
dashboard and crack the plastic case. When I was running a 2-way
radio shop in Smog Angeles area, I was forever replacing Motorola
microphone cases for customers.

The initial Motorola solution was to add some weight to the mic, but
that made things worse. The Motorola mic didn't have much space for
much added weight, so the mic slammed into the dashboard with even
more force. Eventually, Motorola ran out of heavy duty coil cords,
and installed something lighter. The problem was they also switched
from a decent rubber coil cord, to a not so wonderful plastic coil
cord, which would crumble into small pieces when frozen. It took
about 10 years for Motorola to finally get a reliable microphone. The
plastic was thicker, the shell was solvent welded together, some
weight is added inside, it was filled with waterproof foam, and the
coil cord could easily be disconnected and replaced with an RJ45
connector at both ends. The mic element was now electret, but still
simulated a carbon microphone. At the time, replacing the chronic
broken locking tabs on the RJ45 connectors was the only remaining
problem. GE and RCA were not far behind Motorola and successfully
repeated all of Motorola's mistakes and subsequent fixes.

I'm not sure what point CB radio discovered adding "heft" to the
microphone. Oddly, as CB radios shrank, CB microphones became larger
and heavier. There's some odd psychology involved, but since this is
a family newsgroup, I won't go there.

Anyway, the weight added to the microphones had little to do with
marketing, and more to do with users trying to emulate the Boderick
Crawford style of microphone launching.



--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558



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