[GreenKeys] Re: Early Mobile Telephone and associated equipment

[Don Robert House]

Wallace,

Thanks so much for your kind contribution.
It is neat to be able to read some of this history few people know  
about.

God bless,
Don


On 23 Mar 2008, at 9:31 PM, MURRAY, WALLACE W (ATTASIAIT) wrote:

A couple of comments.  The reason for the two antennas was diversity
receivers in the early cell phones.

As far as the teletype in police cars goes, Detroit Police commissioned
a professor at Wayne State University, Bob Leland PE W8??? SK to do a
study in 1968 to 1972 time frame.  He has a grad student, Jack Smith
K8ZOA.  The two borrowed several GE Mastr Pro 450 MHz mobiles from
Michigan Bell (Nick Alympich W8PYW) and modified the limiters so they
could record signal strength with a strip chart recorder.  This was
published in a report. (I had a copy 30 years ago)  They were just
running AFSK Baudot transmission without error correction as I remember
it.  They drove the major streets of Detroit, mapping the signal level.
This really confirmed a Rayleigh model.  Signals fluctuate up and down
by 30 dB over a wave length.

I used this report to get into the radio group.  Michigan Bell had just
installed a Martin Marietta paging system. (Bellboy)  It was running a
800 Baud data rate.  Martin Marietta understood space communications,
but not land mobile digital paging systems.  By using the data in this
report, I suggested that they had 5 one and one half to three mile
radius paging systems, not a continuous coverage system.  Bottom line
was install more transmitters.  An additional 8 sites were added with
higher antennas.  Now the system worked. Then came Pascoag?, FEC, and
other coding schemes. I believe they were using Mighty Might or other
printers.  I will check and get back to you.  I do not believe it was a
Model 15 or Model 28.  By the way, Bob Leland was the first ham I know
who had a Model 28.  His dad Ralph Leland was a retired District Plant
manager.  He was also a ham and involved in Teletype.  He was one of the
hams you contacted that ran the RTTY Society of Michigan who would help
you get a Model 15 or 19.

-----Original Message-----
From: Don Robert House [mailto:k9tty at dls.net]
Sent: Sunday, March 23, 2008 8:18 PM
To: nerd at verizon.net; Duncan-Nancy Brown
Cc: Greenkeys
Subject: Early Mobile Telephone and associated equipment

Happy Easter from the area of two Valentines Day Massacres.

When I was transferred to transmission engineering at Illinois Bell, we
had a district level and staff for radio systems.  The group had a
1 ton Ford van with every kind of radio telephone the company had in
service.  What a monster.  The roof looked like a porcupine with so many
antennas.  If it was black instead of white people would have thought it
was a Secret Service van.  When I had to make field trips I would borrow
the van instead of driving one of the tiny coupes they wanted us to get
from the motor pool.  Trying to maneuver that big van up a circular
drive from a basement garage was quite a trick.  You had to keep blowing
the horn so that no one would try to drive down at the same time you
were driving up.

  We had our problems with AMPS (Advanced Mobile Phone Service) in
Chicago.  An easy place to trial cellular since MOTO is headquartered in
the suburbs.  Early sets were still quite large and had separate control
heads like IMTS, and two antennas on the trunk lid.  In the beginning
there were not enough cell sites and the switching was not always
reliable.  The company's executive limos (navy blue Lincoln Town Cars)
were all equipped with this early cellular equipment.  In those days the
equipment was very expensive.  As more sites were installed the service
became quite reliable until the phones started to become miniaturized.

The first couple of designs of miniature and sub-miniature cellular
phones were provided to the same limos and the earlier larger sets were
removed.  A big mistake.  The small sets would frequently drop calls.
The chauffeurs were responsible for the security of the phones.

One day the first Chairman of Ameritech was talking on one of the new
small phones on Lake Shore Drive.  He lost a call he thought was
important.  He had the chauffeur pull over and he through the phone into
Lake Michigan.  This worried the chauffeur.  He reported the incident to
his foreman as soon as he returned to the company garage.

The foreman told him "If the CEO wants to go for a drive every day along
the lakefront and toss a phone in the lake, don't worry about it.  Just
let me know how many phones I need to order every friday afternoon."

The chairman was, and I suppose, still is one of those egomaniacs that
are "legends in their own minds!  He felt he was so important he
developed a staff larger than AT&T had and had two 727s and four pilots
in a hangar at Midway Airport.  In 1984 because of the funding of
Ameritech, Illinois Bell fell from No. 1 earner in the Bell System to
No. 19. Right down there near Southwestern Bell, system earner number
22.

There are other stories but no one would believe them.  Like picking up
components at Newark on Chicago's west side.  11 foot cyclone fencing
with razor wire and electrically operated "air locks" for secure entry
and exit.  Then there was East St. Louis,  Illinois, the only place in
the Bell System where a cable splicer was shot for his wallet.  The
central office had two armed guards at each entrance 24/7.  If you were
in the building after 4 p.m. you were required to stay overnight in a
bunk room.  No one will admit to it but 90 percent of the employees were
armed.  No one went on a job alone.

Perhaps someone would like to write about the trials of teletypewriters
in police cars.  It would be a little more on subject than mobile
phones...


Don
Ye Olde Telephone Man



On 23 Mar 2008, at 3:55 PM, Peter Gottlieb wrote:

I do remember a bunch about the IMTS system.  I was sent to a course on
setting up one of the latter Motorola IMTS base stations then supervised
and signed off on one such install.  I also had a UHF units in my car,
it was the really big and heavy one which used a varactor tripler to get
into the 450 MHz area.  The PAs were somewhat unreliable.  The
supervisory board was a mass of discrete components and always fun to
work on.  These units used channel elements (crystals mounted in their
own cans with oscillators).  Later on Motorola came out with the
synthesized Pulsar mobiles which were much better.

There were two sets of channels for each city in both VHF and UHF.
One set was for the monopoly carrier (eg, Bell System) and the other set
for the new independent carrier.  There were very few channels as you
note and there was a significant waiting list to get a phone.  If I
remember correctly, it was 6 years in the NYC area.  The IMTS was a
dialtone system; when you went off-hook your phone had an interaction
with the base system where your phone number was sent in and then you
got a dialtone.  Dialing was rotary and tone encoded with parity tones.
When that CO in NYC burned down the Bell System "commandeered"
the IMTS systems and used them for emergency communications with cars
driving around making important calls for people until basic phone
service was restored.

The phones had only 7 digits of phone number setting.  In the Bell
system, the phone number (which was set with jumpers in the phone) was
3 digits for the area code then the last four digits of your mobile
number.  Independents did whatever they wanted, some followed this,
others didn't.

I had a big fat HT-220 which had a bunch of the IMTS channels crystalled
and I could talk to the operator and get her to connect me if I said
some magic words.  This had been loaned to me from one of my clients and
they refused to take it back later.  I think I gave it away when the
battery would no longer hold a charge.

When I bought my first cellular phone Motorola had a deal where you
would get a $500 credit if you turned in your old phone and believe it
or not they took my ancient IMTS unit and I did get that check from
them.  I still see the mobile units and control heads at hamfests.

Word from an insider at Motorola was that the first cellular trial in
NYC was faked.  There was a tech pulling the levers behind the curtain,
the automatic part was not yet ready.  Nevertheless, the technology
behind the idea was sound and developed into the revolution that cell
phones became.

Peter




Duncan M. Brown wrote:
> Anyone with early mobile telephone equipment that you don't know what
> to do with, the Antique Wireless Assoc. Museum would appreciate having

> it.  I have put together a small display of IMTS & early cellular
> equipment for the Museum, but we do not have anything prior to IMTS.
>
>
> A little more history:
>
> The first Bell System Mobile Telephone service began in St. Louis 17
> June
> 1946 on on six channels (120 Kc spacing) in the 152/158 Mc band.
> These
> channels were later split into 60 Kc and then 30Kc channel spacings
> and were given two-letter desiginations starting with "J" or "Y": JL,
> YL, JP, etc. (were one of these letter groups the earlier pre-split
> channels?). There were plans to split the channels again into 15 Kc
> channels with "X"
> designators: eg XJ, XK, etc.  This was never instituted in the US as
> the Cellular channels were finally opened. (But they were in use in
> Canada in
> 1985.)
>
> The Mobile Telephone Highway service started in 1947 in the Boston to
> New York City corridor on 35/44 Mc. and used "Z" designators: ZO, ZF,
> ZH, etc.
> As of 1985, there were still two dozen cities in the US using the Z
> channels. These channels were shut down in about 1988.
>
> In 1956, 12 UHF channels with 25 Kc spacing were made available in the
> 454/459 Mc band and had channel designators starting with "Q": eg QC,
> QJ, QD, etc.
>
> In 1953, AT&T proposed to the FCC a "broadband" mobile telephone
> system operating in the 800Mc region. But it took until 1978 for the
> first cellular test system to go on the air and not until 1983 for the

> first commercial cellular system to go on the air (in Chicago).
>
> IMTS started in 1964 with field trials in Harrisburg, PA.  It was
> initally known as "Interim Mobile Telephone Service" ("interim" until
> cellular was available).  When they realized that cellular was a ways
> off, it was changed to "Improved".
>
>
> Duncan Brown, K2OEQ
>
> AWA Electronic Communication Museum
> http://www.antiquewireless.org
>
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> GreenKeys mailing list
> GreenKeys at mailman.qth.net
> http://mailman.qth.net/mailman/listinfo/greenkeys
>
>
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