I cannot speak on the claim mentioned but I would think it refers to
something regarding the cellular phone era that began commercially in the
1980's. If you look up Mobile Telephone Service on Wikipedia it mentions the
earliest phone services I am aware of; the MTS and then IMTS ("improved")
systems. Full duplex mobile phones were in service in the 1970's. I worked
for a Motorola-owned facility that serviced models they sold.
People may be familiar with the many low (25-40W) powered repeaters
subsequently made by Motorola and others that use mobile radios and small
rectangular cavity notch duplexers that were often made by Phelps-Dodge /
Celwave. These were first used in all those UHF mobile IMTS mobile phones.
Since mobile phones had no other nearby RF sources to worry about they could
use small reject duplexers to notch its own transmitter and receiver
frequency to allow full duplex operation.
I don't know what kind of "black hole research" might have been used in the
VHF, operator assisted service starting in the 1940's as Wikipedia claims.
That is out of my area of expertise and before my time.
We had our ham 2m repeater in the mid-seventies that included a custom
designed and hand-built controller using wire wrapped TTL components
complete with broadcast talent recorded voice announcements on cart tapes or
CW ID and a broadcast Dolby DBX(?) audio compressor/compandor noise
suppression system and fully remote controllable over phone or radio. We had
an excellent autopatch that was used many times to call in emergency service
response. Unfortunately, the FCC had us disable the recorded ID after a few
years. People would kerchunk our repeater to hear the ID which included
everything from Yosemite Sam, Foghorn Leghorn, machine guns firing, hand
grenades exploding, and more. But I think the degree of usage of reverb that
they claimed distorted the actual "ID in the clear" was the objectionable
part. We still have the recordings.
Sorry for the further OT posting.
73's
Kimo Chun, KH7U
Delta Communications, Inc.
Honolulu, HI
Message: 1
Date: Fri, 27 May 2011 19:41:41 -0400
From: "doc@kd4e.com" <doc@kd4e.com>
Subject: [RFI] Didn't mobile phones originate in Ham radio?
To: RFI List <rfi@contesting.com>
Message-ID: <4DE036B5.7090308@kd4e.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
This drifts a wee-bit OT but given the technical-bent of list members I
thought it might appeal to others as it did to me ...
At the end of this article a scientist makes the following claim:
'Do you use a mobile phone? Some of that technology came about by black hole
research'.
http://news.yahoo.com/s/afp/20110527/sc_afp/australiaastrophysicsscience
Is he referring to something in the hardware?
--
Thanks!& 73, KD4E
David Colburn http://kd4e.com <http://kd4e.com/>
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