The Telecom Digest for October 31, 2010
Volume 29 : Issue 293 : "text" Format
Messages in this Issue:
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Date: Fri, 29 Oct 2010 17:35:16 -0700
From: Thad Floryan <thad@thadlabs.com>
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: Happy anniversary cellphone!
Message-ID: <4CCB6844.8030001@thadlabs.com>
On 10/27/2010 7:25 PM, David Clayton wrote:
> On Wed, 27 Oct 2010 13:31:35 -0700, Thad Floryan wrote:
>>> [...]
>> [...]
>> That cannot compare to the thrill of getting a 300 baud modem after
>> starting with a 110 baud acoustic modem and a TTY ASR33. :-)
>
> Ohhh, was it full-duplex or only half? (from someone who remembers when
> 300/1200 FD was a big deal.....)
Thinking back some 40+ years, I seem to remember both the 110 baud
and 300 baud modems had a HDX/FDX switch and a HALF/FULL button,
respectively.
> [...]
> ***** Moderator's Note *****
>
> That's a tricky question! Although TWX Teletype machines, which ran at
> 110 baud, were capable of Full-Duplex, they were wired for Half-Duplex
> and local echo, so an ASR33 might have been Half-Duplex if it had
> been "repurposed" from TWX service. Most Teletype ASR-33 machines were
> connected to external modems, or directly to computers, and were wired
> for Full-Duplex.
>
> Oh, and I remember when 45 Baud Half-Duplex was a big deal: I learned
> to type on a Model 19 Teletype machine at the MIT radio club.
ISTR the MARS (Military Affiliate Radio Station) facility at
Fort Sam Houston (San Antonio) Texas had one of those back in
the 1950s. Seems they changed to "Affiliate" from "Auxiliary"
in 1952 per:
http://en.wikipedia.org/wiki/Military_Auxiliary_Radio_System
I "played" there a lot (just 1/2 mile (easy walk) from my home)
back when I was learning Morse code. I was the first kid in over
20 years to get the Boy Scout 'Signaling' merit badge in Troop 23.
***** Moderator's Note *****
The Boy Scouts have revived the "Signalling" badge for their 100th
anniversary, and it requires both Morse code and either Semaphore or
light signalling. The speeds, moreover, are very modest.
Bill Horne
Moderator
Date: 30 Oct 2010 19:44:21 -0000
From: John Levine <johnl@iecc.com>
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: Happy anniversary cellphone!
Message-ID: <20101030194421.56117.qmail@joyce.lan>
> Thinking back some 40+ years, I seem to remember both the 110 baud
> and 300 baud modems had a HDX/FDX switch and a HALF/FULL button,
> respectively.
110 and 300 bps ttys used the same Bell 103 modems, a simple FSK
scheme with originate 1,270/1,070 Hz and answer 2,225/2,025 Hz. The
modems were full duplex. TTYs could be set for local echo or not, and
it is my recollection that for some reason TWX modems switched the
frequency pairs relative to the dialup 103s so they couldn't
interoperate.
TWX modems also had a "restrain" signal which paused the paper tape
reader, allowing TWX-Telex (100 speed ASCII to 50 speed Baudot)
translators to catch up. Dunno what frequency that was.
R's,
John
***** Moderator's Note *****
The TWX used the same modem tones and transmission standards as
"ordinary" modems: I know, because I used to use a Model 35 TWX
machine to log in to Ward Christenen's CBBS from the Back Bay Toll
office in the 1970's, and I also used that same machine to test TWX
circuits when Western Union called in a complaint - it was a really
nice way to get rid of Friday-afternoon "dump jobs" very quickly.
WU loved to blame "Ma Bell", but sending their customer an actual
Teletype message that said "It's WU's problem" would end any
arguments: WU didn't like it, mostly because nobody in N.E.T. had ever
thought of it before.
The Restrain signal wasn't a separate tone: it was simply Mark and
Space tones sent at the same time.
Bill "Finally, something I know a lot about" Horne
Moderator
Date: Sat, 30 Oct 2010 21:20:53 +0000 (UTC)
From: richgr@panix.com (Rich Greenberg)
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: Happy anniversary cellphone!
Message-ID: <iai27l$sgj$1@reader1.panix.com>
In article <20101030194421.56117.qmail@joyce.lan>,
John Levine <johnl@iecc.com> wrote:
>TWX modems also had a "restrain" signal which paused the paper tape
>reader, allowing TWX-Telex (100 speed ASCII to 50 speed Baudot)
>translators to catch up. Dunno what frequency that was.
>***** Moderator's Note *****
>The Restrain signal wasn't a separate tone: it was simply Mark and
>Space tones sent at the same time.
Not being too familiar with TWX, Bill could be right about the two
simultanious tones, but the way it was done in the networks I worked
with involved 2 control characters, "Xon" and "Xoff". An xoff from
the receiving end told the sending end to stop sending. Later, an xon
told the sender to continue where it left off. Full duplex was
required. ISTR that one of them was Ctrl+Q and the other was Ctrl+S but
I don't recall which was which, and I am too lazy to get up and find my
tty refrence card. But then I remembered Wikipedia, so see:
http://en.wikipedia.org/wiki/Software_flow_control
for all the gory details (including which was Cntl+Q and which was
Ctrl+S).
Because the IBM 2701 the time sharing system I was using didn't support
FDX or mabe it was xon/xoff or mabe it was an expensive option we didn't
have (don't recall which) we had a software fix for preventing buffer
overrun of the TWX-Telex translator (we ran 100 speed, the translator
o/p was 60 (or 66) speed). We took the o/p string to be sent and
inserted a null between each character giving us an effective o/p of 50
speed.
--
Rich Greenberg Sarasota, FL, USA richgr atsign panix.com + 1 941 378 2097
Eastern time. N6LRT I speak for myself & my dogs only. VM'er since CP-67
Canines: Val, Red, Shasta, Zero & Casey (At the bridge) Owner:Chinook-L
Canines: Red & Cinnar (Siberians) Retired at the beach Asst Owner:Sibernet-L
***** Moderator's Note *****
Between ASCII Teletype machines, the codes DC2 and DC4 were used to
control the tape reader: they were labelled "TAPE ON" and "TAPE OFF"
respectively, and a "local" machine could stop the tape reader on a
"remote" machine by sending "TAPE OFF", and start it by sending "TAPE
ON".
Teletype machines had "answerback" capability: it was a hand-coded
drum that sent a prerecorded id code, and it would respond whenever
the machine received a "WRU" (Who Are You) code, which is an "ENQ"
character in ASCII. I mention this because TWX machines were set up to
send their answerback code automatically after they answered an
incoming call. In Model 33 Teletype school, I was taught to code a
"TAPE ON" (DC2) character as the last character sent during
answerback, so as to start the tape reader on the calling machine: it
was a courtesy that cut down on call durations.
I don't know why 100-speed TWX machines used "hardware" flow control,
i.e., why their Restrain signal was composed of simultaneous Mark and
Space tones. It might have been a holdover from the 60-speed network,
or possibly it was required by intermediate stations that couldn't add
characters to the data stream, such as tape-relay points, TELEX <> TWX
gateways, etc. I'm guessing, either way: I know that DC1 and DC3 are
the workhorse characters for software flow control when a terminal is
connected to a computer, but in the TWX world, it was "Restrain"
instead of DC4/DC2 that was used to control tape transmission.
Bill Horne
Moderator
Date: Fri, 29 Oct 2010 17:45:24 -0700
From: Thad Floryan <thad@thadlabs.com>
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: Disconnected: Attention Passengers it's perfectly safe to use your cellphones
Message-ID: <4CCB6AA4.4040604@thadlabs.com>
On 10/27/2010 9:59 PM, Robert Bonomi wrote:
> In article <pan.2010.10.27.21.53.31.460692@myrealbox.com>,
> David Clayton <dcstar@myrealbox.com> wrote:
>> On Tue, 26 Oct 2010 22:04:08 -0500, Gordon Burditt wrote:
>>
>>>> Experts I've read claim the problem is a cell phone at such an altitude
>>>> would light up too many cell towers and the towers couldn't handle the
>>>> hand offs of such a fast moving phone.
>>> That would tie up one frequency in each of however many cells you lit up
>>> (maybe hundreds).
>> Can someone explain to me how cell towers - which must have antenna arrays
>> deliberately designed with focussed radiation patterns to maximise the
>> signal going to handsets either on the horizontal plane to the tower, or
>> below that plane - are able to somehow connect with all these handsets
>> above them (way, way above them)?
>
> The answers are to be found in spherical trig, and _absolutely_
> _unobstructed_ signal paths.
> [...]
I agree. Anyone wanting a refresher and a note about haversines
might get a kick out of this article I posted to sci.math back
in 1988, some 22 years ago:
http://groups.google.com/group/sci.math/msg/d6c891302914fd84
or
http://groups.google.co.jp/group/sci.math/msg/d6c891302914fd84
:-)
Date: Sun, 31 Oct 2010 09:33:04 +1100
From: David Clayton <dcstar@myrealbox.com>
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: Disconnected: Attention Passengers it's perfectly safe to use your cellphones
Message-ID: <pan.2010.10.30.22.33.01.100590@myrealbox.com>
On Fri, 29 Oct 2010 17:45:24 -0700, Thad Floryan wrote:
> On 10/27/2010 9:59 PM, Robert Bonomi wrote:
>> In article <pan.2010.10.27.21.53.31.460692@myrealbox.com>, David Clayton
>> <dcstar@myrealbox.com> wrote:
>>> On Tue, 26 Oct 2010 22:04:08 -0500, Gordon Burditt wrote:
>>>
>>>>> Experts I've read claim the problem is a cell phone at such an
>>>>> altitude would light up too many cell towers and the towers couldn't
>>>>> handle the hand offs of such a fast moving phone.
>>>> That would tie up one frequency in each of however many cells you lit
>>>> up (maybe hundreds).
>>> Can someone explain to me how cell towers - which must have antenna
>>> arrays deliberately designed with focussed radiation patterns to
>>> maximise the signal going to handsets either on the horizontal plane to
>>> the tower, or below that plane - are able to somehow connect with all
>>> these handsets above them (way, way above them)?
>>
>> The answers are to be found in spherical trig, and _absolutely_
>> _unobstructed_ signal paths.
>> [...]
>
> I agree. Anyone wanting a refresher and a note about haversines might get
> a kick out of this article I posted to sci.math back in 1988, some 22
> years ago:
>
> http://groups.google.com/group/sci.math/msg/d6c891302914fd84 or
> http://groups.google.co.jp/group/sci.math/msg/d6c891302914fd84
Ok, the reasoning does make sense of how a handset in flight can get a
RF path to multiple towers on the ground, but don't all the cell phone
protocols specifically pick out the strongest/most available signal
and then connect to that?
Wouldn't that prevent the "connecting to multiple towers" issue that
has been mentioned?
--
Regards, David.
David Clayton
Melbourne, Victoria, Australia.
Knowledge is a measure of how many answers you have, intelligence is a
measure of how many questions you have.
Date: Fri, 29 Oct 2010 18:19:47 -0700
From: Thad Floryan <thad@thadlabs.com>
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: Please identify this hold music
Message-ID: <4CCB72B3.4050403@thadlabs.com>
On 10/17/2010 9:16 PM, Rudy Valencia wrote:
> [...]
> I'm trying to identify the hold music I recorded at
> http://rudyvalencia.com/instrumental.mp3 and I'm hoping the people
> that read this could help.
>
> I've heard a longer version than the 30-second snippet here, and I'm
> trying to find it.
>
> I would appreciate it if I could at least know the name of it, or even
> better, if I could know how to obtain the longer version somehow.
> [...]
My music friend in Reno just emailed me a URL to something that
may identify the tune. This looks promising; let us know how it
works out for you. Download from here:
http://www.wildbits.com/tunatic/
It looks like you'll have to play the tune into a microphone used
by the app (for either Mac or Windows), but the FAQ has this:
" * Most PC sound cards allow you to select "What You Hear"
" (also named "Stereo Mix" or "Mixed Output") as input. To
" get there, right-click Tunatic's window, select "preferences",
" then click the "Configure..." button.
" * If your hardware allows it, plug your sound output to your
" sound input. It's ugly, but it works!
The FAQ is here:
http://www.wildbits.com/tunatic/faq.html
Date: Fri, 29 Oct 2010 22:32:22 -0700
From: Thad Floryan <thad@thadlabs.com>
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Crackdown on phone bill 'cramming' falls short
Message-ID: <4CCBADE6.6000704@thadlabs.com>
This is not good.
<http://www.latimes.com/business/la-fi-lazarus-20101029,1,7999841.column>
Crackdown on phone bill 'cramming' falls short
By David Lazarus October 29, 2010
It's too easy for people to get stuck with unauthorized charges,
so the state PUC has ordered companies like AT&T and Verizon to
ensure that third-party billings are legit. That's fine, but
other safeguards are necessary.
State regulators voted Thursday to crack down on unauthorized
charges appearing on people's phone bills, a practice known in
telecom circles as "cramming."
For the first time, service providers like AT&T and Verizon will
be responsible for investigating companies that add charges to
bills and ensuring that the charges are legit. The phone
companies themselves will also be responsible for refunding all
unauthorized charges.
"Too often, the phone companies have allowed scammers access to
unwitting consumers," said Mark Toney, executive director of
the Utility Reform Network, an advocacy group. "Phony voice-mail
services are a common one."
Hancock Park resident Peter Lee can attest to that. He recently
noticed a pair of monthly charges for $8.23 each on his AT&T
bill. Calling the number associated with the charges, he
discovered that he'd been signed up for something called
InfoBilling, a voice-mail service he never ordered.
His experience illustrates the ease with which consumers can get
saddled with unexpected charges -- and the need for regulations
that go even further than Thursday's action by the California
Public Utilities Commission.
When Lee investigated what happened, he was told that
InfoBilling's customer service was being handled by another
company, MyService and Support. The MyService rep said that
even though the voice-mail account was registered to Lee's
AT&T number, it was in someone else's name.
The rep said she would close down the account and credit Lee
for the two months' charges.
Curious about how his phone number had become linked to some
voice-mail thing he'd never heard of, Lee went to
InfoBilling.com and discovered how easy it is to stick someone
with the bill.
Apparently all you have to do is list someone's phone number
on the sign-up form and -- voila -- the monthly fees go there.
"It's really easy to do," Lee, 54, told me.
He called InfoBilling a "shoddy scam."
{ article continues at the following URL }
http://www.latimes.com/business/la-fi-lazarus-20101029,1,7999841.column
"Shoddy scam" is putting it mildly.
Date: 30 Oct 2010 00:25:12 -0000
From: John Levine <johnl@iecc.com>
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: paypass, was A Simple Swipe on a Phone
Message-ID: <20101030002512.74231.qmail@joyce.lan>
>Perhaps just urban legend, but I've heard of a Speedpass user who, prior
>to relocating across the country, sought to have his Speedpass device
>taken out of service. "UPS it to its issuer," was the advice he got ...
>
>... and followed. Then, at the usual time of the month, a Speedpass bill
>got forwarded to his new address, with some 38 toll collections, 19 in
>each direction, at a NJTPke toll booth near his former home, all for
>transits after he sent his Speedpass in for deactivation.
Speedpass is Exxon/Mobil's pay at the pump keychain thing. You're
thinking of E-ZPass, the automated toll collection system. This
particular story is likely an urban legend, but it is a real problem.
The device has a battery which runs down after a few years, and when
they want you to replace it, they send you a metallized plastic read
prevention bag in which to mail it back, to prevent just this kind of
problem.
R's,
John
Date: 30 Oct 2010 00:26:24 -0000
From: John Levine <johnl@iecc.com>
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: Afternoon texting hike up Mount Everest
Message-ID: <20101030002624.74535.qmail@joyce.lan>
>Those who have trekked it to the top will soon able to call
>their mates, go on Facebook or Twitter and boast that they've
>got there thanks to TeliaSonera and its subsidiary in Nepal,
>Ncell, which have bought 3G to the Mount Everest area. ...
Heard on the CBC this evening in connection with this story:
Why are calls from Mt Everest so expensive?
Because you're always using peak minutes.
R's,
John
Date: Thu, 28 Oct 2010 05:10:30 +0000 (UTC)
From: danny burstein <dannyb@panix.com>
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: Disconnected: Attention Passengers it's perfectly safe to use your cellphones
Message-ID: <iab0k6$28j$1@reader1.panix.com>
In <4CC8B657.40002@thadlabs.com> Thad Floryan <thad@thadlabs.com> writes:
>A quick Google search turns up many references corroborating terrestrial-
>oriented alignment of antennas. This site has mixed commentary, to wit:
>http://www.rense.com/general56/cellpp.htm
>" [...]
>" An airplane is made of aluminum alloy. It is NOT transparent to RF
>" frequencies, but instead acts as a shield. Sections of the plane
>" made of carbon composite will greatly attenutate or even stop all
>" cell phone signals, as this is also conductive material.
I'd guess that the author of that piece has never sat in an
aircraft taxiing towards the terminal after the pilot has
said "ok, you can all turn on your cellphones now".
Suffice to say that attenuation does NOT mean fully blocked,
by any means.
>However, we all remember 9/11 and the cellphone conversations by
>the heroic passengers of UA Flight 93 who retook the plane from the
>terrorists but sadly later crashed in Pennsylvania. Per Wikipedia:
>http://en.wikipedia.org/wiki/United_Airlines_Flight_93
>" [...]
>" Altogether, the passengers and crew made 35 airphone calls and two
>" cell phone calls from the flight.
>So, cellphone connections can be made from an aircraft flying at
>altitude, but whether that's coincidence or pure_luck or by design
>is still up in the air (no pun).
Leaving aside the special circumstances of the 9/11 flights,
the fact that a ground based (or 100 foot high, perhaps)
antenna is horizontally aimed (that is, parallel to the
ground) simply means that the best signal to an overflying
aircraft won't be to the tower directly beneath it. It'll
be to a tower perhaps five miles away that's within the
(roughly) parallel-to-the-ground beam spread.
And that could easily be a dozen towers on all sides of the compass.
Or more.
Fwiw, I had a chat with the folk at a small general aviation
airport in mid country. They said it's routine for pilots
to call the tower when ten or fifteen minutes away and thousands
of feet up to get the number of the cab company...
--
_____________________________________________________
Knowledge may be power, but communications is the key
dannyb@panix.com
[to foil spammers, my address has been double rot-13 encoded]
Date: Thu, 28 Oct 2010 05:43:07 -0500
From: rpw3@rpw3.org (Rob Warnock)
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: Disconnected: Attention Passengers it's perfectly safe to use your cellphones
Message-ID: <eIedncApRtwmzlTRnZ2dnUVZ_hOdnZ2d@speakeasy.net>
Lisa or Jeff <hancock4@bbs.cpcn.com> wrote:
+---------------
| > ***** Moderator's Note *****
| > Although modern avionics have better components and design than those
| > used in the last century, it's not possible to make them
| > "jam-proof". This may surprise you, but aircraft still use Amplitude
| > Modulation for voice...
|
| I'm surprised they still use AM. IIRC, back in WW II radios in tanks
| originally used AM but then switched to FM (from the Bell System
| History "War & Peace").
+---------------
There's a perfectly good reason for aviation sticking with AM: the FM
"capture effect", where when two signals are transmitting on the same
frequency an even slightly stronger signal "captures" the receiver
due to the action of the limiter (R.F. clipper) in the I.F. chain.
This is great for broadcast entertainment, since it cuts out interference
from distant stations. But it's terrible for aviation, where you need
to be able to hear when two airplanes are transmitting at the same time
("stepping on" each other), so that you know information has been lost
and/or you can send a warning/request to re-transmit after a collision.
Typical exchamge:
ATC: Delta 1234, climb/maintain flight level 280.
Anon 3rd party: Blocked! [They heard ATC being stepped on.]
ATC: Delta 1234, climb/maintain flight level 280; break; other party
transmitting, say again.
Other: Approach, United 987 with you [rest of call up]...
+---------------
| Would a portable AM/FM radio (eg a "Walkman") today be a risk of
| interference to an airplane's electronics?
+---------------
Quite possibly! Aviation uses frequencies of 108-117.975 MHz
for navigation aids such as VOR & ILS and 118-137 MHz for voice
communications, just above the FM broadcast band of 88-108 MHz.
Traditional (and even today, cheap) FM radios use an I.F. frequency
of 10.7 MHz, with the local oscillator being 10.7 MHz above
the desired signal one is receiving. Thus pretty much the entire
navigation aid spectrum (and a tiny portion of the aviation voice
band) is subject to potential interference from an operating FM radio
that's tuned to an unfortunate frequency.
-Rob
Rob Warnock <rpw3@rpw3.org>
627 26th Avenue <URL:http://rpw3.org/>
San Mateo, CA 94403 (650)572-2607
Date: Sat, 30 Oct 2010 18:39:32 -0400
From: tlvp <tPlOvUpBErLeLsEs@hotmail.com>
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: Disconnected: Attention Passengers it's perfectly safe to use your cellphones
Message-ID: <op.vleuj6x1itl47o@acer250.gateway.2wire.net>
On Thu, 28 Oct 2010 06:43:07 -0400, Rob Warnock <rpw3@rpw3.org> wrote:
> ...
> There's a perfectly good reason for aviation sticking with AM: ...
> ... you need to be able to hear when two airplanes are
> transmitting at the same time ("stepping on" each other), so that
> you know information has been lost and/or you can send a
> warning/request to re-transmit after a collision.
Or, better yet, before one, as "after" is a mite too late :-) .
Cheers, -- tlvp
--
Avant de repondre, jeter la poubelle, SVP
Date: Thu, 28 Oct 2010 07:04:45 -0700 (PDT)
From: Harold Hallikainen <harold@hallikainen.com>
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: Disconnected: Attention Passengers it's perfectly safe to use your cellphones
Message-ID: <fc7f9dda-5c45-49d5-900e-7f4e7a343ca6@l8g2000yql.googlegroups.com>
On Oct 27, 10:50 am, Lisa or Jeff <hanco...@bbs.cpcn.com> wrote:
> Would a portable AM/FM radio (eg a "Walkman") today be a risk of
> interference to an airplane's electronics?
I think the greatest potential interference would be with an FM
receiver. They've traditionally used a 10.7MHz IF with high side local
oscillator injection. That puts the LO in the aircraft band. LO
radiation could interfere with aircraft communications and navigation
(especially VOR).
Harold
Date: 28 Oct 2010 16:02:22 -0400
From: kludge@panix.com (Scott Dorsey)
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: Disconnected: Attention Passengers it's perfectly safe to use your cellphones
Message-ID: <iackse$imb$1@panix2.panix.com>
Lisa or Jeff <hancock4@bbs.cpcn.com> wrote:
>On Oct 26, 11:04 pm,
>
>> ***** Moderator's Note *****
>>
>> Although modern avionics have better components and design than those
>> used in the last century, it's not possible to make them
>> "jam-proof". This may surprise you, but aircraft still use Amplitude
>> Modulation for voice, which means that they're still subject to
>> interference from a variety of noise sources, just like the AM radio
>> stations that still suffer from static when your car goes under a
>> power line. I'm not sure if a VOR can be considered an "AM"
>> transmitter, but the Instrument Landing System's Locator and Glide
>> Slope transmitters certainly are.
>
>I'm surprised they still use AM. IIRC, back in WW II radios in tanks
>originally used AM but then switched to FM (from the Bell System
>History "War & Peace").
The issue is that with AM there is no capture phenomenon, so two people can
speak at the same time, stepping on one another, and both are heard. Pilots
consider this a big issue for safety... you don't have to wait for a free
time period to get your mayday call in.
The military went to FM for short distance comms during WWII, and never
looked back.
>Would a portable AM/FM radio (eg a "Walkman") today be a risk of
>interference to an airplane's electronics?
Yes. If anything, modern radios radiate even more noise than older ones
because more cost-engineering has been done... adding shielding costs money.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
Date: Thu, 28 Oct 2010 08:30:06 +0200
From: Marc Haber <mh+usenetspam1002@zugschl.us>
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: Disconnected: Attention Passengers it's perfectly safe to use your cellphones
Message-ID: <iab59e$589$1@news1.tnib.de>
snorwood@redballoon.net (Scott Norwood) wrote:
>Amtrak has this. They call it the Quiet Car, and there is one on
>most train routes (at least in the Northeast; other regions may be
>different). Passengers are asked not to use any device that makes
>noise (including cell phones), and to talk amongst themselves only
>in quiet voices. The train conductors enforce this policy.
>Passengers who wish to make more noise can choose to sit elsewhere.
>The system works quite well in my experience.
Germany has a system like that as well, and it doesn't work at all.
Even Families with three kids in "loud" ages get booked into the quiet
car, and the conductors don't care.
The quiet car doesn't have cell phone repeaters, so people with phones
and computers tend to sit somewhere else, but noone cares about other
noises.
Greetings
Marc
--
-------------------------------------- !! No courtesy copies, please !! -----
Marc Haber | " Questions are the | Mailadresse im Header
Mannheim, Germany | Beginning of Wisdom " | http://www.zugschlus.de/
Nordisch by Nature | Lt. Worf, TNG "Rightful Heir" | Fon: *49 621 72739834
Date: Thu, 28 Oct 2010 06:53:48 -0700 (PDT)
From: "Harold Hallikainen" <harold@hallikainen.com>
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: Did Charlie Chaplin film a cell phone in 1928?
Message-ID: <be1100cd-b290-4a86-b73d-1f7461c31495@c20g2000yqj.googlegroups.com>
On Oct 27, 10:57 am, Lisa or Jeff <hanco...@bbs.cpcn.com> wrote:
>
> Would anyone know when police radios for automobiles came out? I
> recall it was after WW II. Before then police used call boxes located
> on street corners; rural police were on their own.
It looks like police radio was running in 1931. See
http://louise.hallikainen.org/BroadcastHistory/index.php/HomePage#Policex20.Radio
I believe it was one way dispatch, though. I remember being in the San
Francisco east bay area in the 1950s and listening to the Los Angeles
police on the 1.7MHz police band. Remember this band was marked on
radios of the time?
Harold
Date: Thu, 28 Oct 2010 22:06:50 GMT
From: sfdavidkaye2@yahoo.com (David Kaye)
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: Did Charlie Chaplin film a cell phone in 1928?
Message-ID: <iacs5l$fas$3@news.eternal-september.org>
Lisa or Jeff <hancock4@bbs.cpcn.com> wrote:
>However, the transmitter gear was enormous and required constant
>monitoring and adjustment. I believe originally it was long wave, not
>short wave.
>From the video it looks like the instrument could have been an ear trumpet.
>Would anyone know when police radios for automobiles came out? I
>recall it was after WW II. Before then police used call boxes located
>on street corners; rural police were on their own.
In the late 1950s people used to tune in the SF Bay Area to 1610 to listen to
police calls. They originated from the PD, none from the cars as far as I
know, so it was just a base station with no remotes.
Date: Thu, 28 Oct 2010 23:37:38 +0000 (UTC)
From: dwolffxx@panix.com (David Wolff)
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: Did Charlie Chaplin film a cell phone in 1928?
Message-ID: <iad1g2$dng$1@reader1.panix.com>
In article <alpine.WNT.2.00.1010281444530.3344@AURM106297.americas.ad.flextronics.com>,
John Mayson <john@mayson.us> wrote:
> On Wed, 27 Oct 2010, Steven wrote:
>
> > It could be a hearing add, they were about the same size as cell phones are
> > today.
>
> That crossed my mind, but no one appeared to be speaking to her.
>
> I'm certain there's a rational explanation. But it's still pretty
> strange.
Scratching her ear, or brushing back her hair. Note the first two
fingers are together, which doesn't correspond well with holding
anything. And the "device" is not really visible.
If you look at lots of things, you will eventually find something that
looks like a penguin, or [Senator] Goldwater, or Jesus climbing a
telephone pole...
Thanks --
David
(Remove "xx" to reply.)
Date: Thu, 28 Oct 2010 21:40:46 -0400
From: Ron <ron@see.below>
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: Did Charlie Chaplin film a cell phone in 1928?
Message-ID: <hu8kc65n6s7g5612l5kf4ov04lbrrllj06@4ax.com>
Thad Floryan <thad@thadlabs.com> wrote:
>On 10/27/2010 3:55 PM, Steven wrote:
>> On Oct 26, 10:14 pm, Thad Floryan<t...@thadlabs.com> wrote:
>>> [...]
>>> Of course, there were no cell phones in 1928. And even if this
>>> was a time traveler, there would be no cell towers to handle
>>> [...]
>> It could be a hearing add, they were about the same size as cell phones
>> are today.
>
>That's my original thought, too, but look at what was available
>circa the 1920s:
--snip of nice process of elimination. --
I had a chance to look at the film clip on Youtube. What I saw
removes it from the telecom world.
As a 21st century observer, we see the familiar cell phone
grip. This same grip would be used to hold the top of her coat
against her face. Watch it again with this in mind, and see if
this more mundane explanation works for you.
--
Ron
(user telnom.for.plume
in domain antichef.com)
Date: Fri, 29 Oct 2010 19:34:36 -0700 (PDT)
From: Lisa or Jeff <hancock4@bbs.cpcn.com>
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: Happy anniversary cellphone!
Message-ID: <f8ef77e0-96b2-4ace-8974-cc811e261441@e14g2000yqe.googlegroups.com>
On Oct 27, 10:25 pm
> ***** Moderator's Note *****
>
> That's a tricky question! Although TWX Teletype machines, which ran at
> 110 baud, were capable of Full-Duplex, they were wired for Half-Duplex
> and local echo, so an ASR33 might have been Half-Duplex if it had
> been "repurposed" from TWX service. Most Teletype ASR-33 machines were
> connected to external modems, or directly to computers, and were wired
> for Full-Duplex.
>
> Oh, and I remember when 45 Baud Half-Duplex was a big deal: I learned
> to type on a Model 19 Teletype machine at the MIT radio club.
We thought it was a big deal when we could dial up (TTY 33 ASR 110
baud) to a computer to do hairy math calculatons quickly and
accurately that for us would be error prone and tedious to do
manually. Slide rules were a pain for us. Don't forget, in those
days pocket calculations weren't out yet, and when they did first come
out they were quite expensive.
Many time sharing services we used were half duplex.
Some were full duplex but the echo was slow. You'd type and hear a
"blurp" on the keyboard and a half second later the character would
type on the machine. Sometimes a few characters would pop out at
once. (That happens to me now on Usenet sometimes).
As to old phone numbers, I wonder how many landline numbers are over
50 years old. Given how often people move these days, I suspect very
few. I do know of an old church whose number was shown as "23" in an
ancient phone book, and is NPA-NNX-0023 today.
I wonder if any old-style mobile customers could keep their own phone
number when they switched to cellular. I doubt it since the old style
were centralized and the new style was more neighborhood driven in
special exchanges.
Date: Sat, 30 Oct 2010 18:55:11 -0400
From: tlvp <tPlOvUpBErLeLsEs@hotmail.com>
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: Happy anniversary cellphone!
Message-ID: <op.vleu99anitl47o@acer250.gateway.2wire.net>
On Fri, 29 Oct 2010 22:34:36 -0400, Lisa or Jeff <hancock4@bbs.cpcn.com>
wrote:
> ... As to old phone numbers, I wonder how many landline numbers are over
> 50 years old. Given how often people move these days, I suspect very
> few. ...
Heh ... not 50 years old, in my case, but close: 43 (since late summer
of 1967). But a recently deceased older cousin in NYC had one
landline number from the time of his arrival on W. 4th St. circa 1951
through the time of his death in 2009.
Cheers, -- tlvp
--
Avant de repondre, jeter la poubelle, SVP
Date: Sat, 30 Oct 2010 15:34:38 +0000 (UTC)
From: Paul <pssawyer@comcast.net.INVALID>
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: paypass, was A Simple Swipe on a Phone
Message-ID: <Xns9E2175C57F6C1Senex@85.214.73.210>
tlvp <tPlOvUpBErLeLsEs@hotmail.com> wrote in
news:op.vk9kwddsitl47o@acer250.gateway.2wire.net:
> On Tue, 26 Oct 2010 22:50:04 -0400, John Levine <johnl@iecc.com>
> wrote:
>
>>
>> ... Speedpass is an older and more primitive technology.
>> My recollection (I had one which I dropped and some kid picked it
>> up and used it to buy gas all over central NY) that it does work
>> at considerably more than an inch.
>> ...
>
> Perhaps just urban legend, but I've heard of a Speedpass user who,
> prior to relocating across the country, sought to have his
> Speedpass device taken out of service. "UPS it to its issuer," was
> the advice he got ...
>
> ... and followed. Then, at the usual time of the month, a
> Speedpass bill got forwarded to his new address, with some 38 toll
> collections, 19 in each direction, at a NJTPke toll booth near his
> former home, all for transits after he sent his Speedpass in for
> deactivation.
>
> TMALSS, it turns out the UPS flat his Speedpass got itself sent in
> slipped behind the dash of a UPS delivery van, and was dinging up
> a toll every time it passed through a NJTPke Speedpass lane toll
> both, day in, day out :-) .
>
> Or so I've seen it recounted :-) .
>
> Cheers, -- tlvp
I think speedpass is the RFID device used at Exxon and Mobil gas
pumps.
If you mean something like E-ZPass, I did have a similar experience
to the one you describe. I originally had a NJ E-ZPass account.
When NH began using E-ZPass, I had to get new transponders, in order
to get the in-state discounts. When I sent the NJ transponder back,
a toll in NJ showed on my final bill. A simple phone call
straightened that out, as it was obvious what happened. (Later, a
toll billed to a license plate not even related to me, not a
transponder number, could not be straightened out by e-mail OR phone,
thankfully we have walk-in offices in NH, with customer service
people who do understand logic.)
--
Paul
Date: Wed, 27 Oct 2010 20:30:25 EDT
From: Wes Leatherock <wesrock@aol.com>
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: Happy anniversary cellphone!
Message-ID: <e55cf.dc33c6c.39fa1e21@aol.com>
In a message dated 10/27/2010 5:23:15 PM Central Daylight Time,
johnl@iecc.com writes:
>> 339-DOG-TITS. Beat that for being easy to remember!
>
> My 800 number spells my wife's name. I think that's why she
> finally agreed to marry me.
A reporter on our company (SWBell Oklahoma) employee newspaper went to
Stillwater to do a story on the fall enrollment rush at the business
office. (I believe the business office had a set up on the camous
where students arrived.) They had a list of numbers they would not
assign because of what they spelled. One of them spelled TITS. I
don't remember some of the others.
Wes Leatherock
wesrock@aol.com
wleathus@yahoo.com
Date: Wed, 27 Oct 2010 20:38:47 EDT
From: Wes Leatherock <wesrock@aol.com>
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: Did Charlie Chaplin film a cell phone in 1928?
Message-ID: <e5cf1.75fac7fa.39fa2017@aol.com>
In a message dated 10/27/2010 5:34:48 PM Central Daylight Time,
hancock4@bbs.cpcn.com writes:
> While mobile radio sets would be developed for the military in WW II
> (and probably beforehand), mobile telephones for autos and trains did
> not come out until 1948.
>
> Would anyone know when police radios for automobiles came out? I
> recall it was after WW II. Before then police used call boxes located
> on street corners; rural police were on their own.
When I was a teenager (before and during World War II). I enjoyed
listening to the Oklahoma Highway Patrol radio traffic on 1626 kHz
(then called 1626 kc), easily accessible on many broadcast receivers.
Wasn't KOP, the Detroit Police Radio System call letters., in
operation several years before that? I graduated from college in 1949
and there was a police scanner on the city desk at the Oklahoman and
not considered a new innovation.
Wes Leatherock
wesrock@aol.com
wleathus@yahoo.com
Date: Sat, 30 Oct 2010 20:16:35 +0000 (UTC)
From: Paul <pssawyer@comcast.net.INVALID>
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: Did Charlie Chaplin film a cell phone in 1928?
Message-ID: <Xns9E21A5934CF82Senex@85.214.73.210>
Wes Leatherock <wesrock@aol.com> wrote in
news:e5cf1.75fac7fa.39fa2017@aol.com:
> When I was a teenager (before and during World War II). I enjoyed
> listening to the Oklahoma Highway Patrol radio traffic on 1626 kHz
> (then called 1626 kc), easily accessible on many broadcast
> receivers.
When I was a teenager, early 1960s, NH SP still had a base station on
1682 kHz AM on top of Mt. Washington, which covered the entire state,
and was used for general broadcasts and messages to cities and towns.
Most towns and cities monitored this, and some could talk back (on
37.18 mHz FM, IIRC). Somehow, many of our AM only car radios had
slipped their tuning to receive 1682...
> Wasn't KOP, the Detroit Police Radio System call letters., in
> operation several years before that? I graduated from college in
> 1949 and there was a police scanner on the city desk at the
> Oklahoman and not considered a new innovation.
I doubt that it was a scanner, but ICBW.
--
Paul
Date: Sat, 30 Oct 2010 09:35:49 EDT
From: Wes Leatherock <wesrock@aol.com>
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: Did Charlie Chaplin film a cell phone in 1928?
Message-ID: <21a192.17a92256.39fd7935@aol.com>
In a message dated 10/29/2010 6:05:01 PM Central Daylight Time,
thad@thadlabs.com writes:
On 10/27/2010 11:21 PM, Thad Floryan wrote:
>> On 10/27/2010 3:55 PM, Steven wrote:
>>> On Oct 26, 10:14 pm, Thad Floryan<t...@thadlabs.com> wrote:
>>>> [...]
>>>> Of course, there were no cell phones in 1928. And even if this
>>>> was a time traveler, there would be no cell towers to handle
>>>> [...]
>>> It could be a hearing add, they were about the same size as cell phones
>>> are today.
>>
>> That's my original thought, too, but look at what was available
>> circa the 1920s:
>>
>>
>> http://hearing.siemens.com/sg/10-about-us/01-our-history/milestones.jsp?year=1924
>> [...]
>> Another site:
>>
>> http://beckerexhibits.wustl.edu/did/20thcent/index.htm
>>
>> is really interesting: concealed hearing devices of the 20th century.
>> [...]
>
> Another possibility regarding hearing aids is the WE 34a:
>
> <http://www.hearingaidmuseum.com/gallery/Carbon/WesternElectric/info/westele
> ct34a.htm>
>
> but it still doesn't look like the brief image in the Chaplin film.
>
> And there's still the issue of to whom is the woman speaking.
>
> I found another incidence of a purported time traveler in Canada at
> the reopening of a bridge destroyed in a flood in the 1940s with this
> opening line:
>
> " The man with what appears to be very modern sunglasses seems to be
> " wearing a stamped T-shirt with a nice sweater, all the while holding
> " a portable compact camera!"
>
> here:
>
> http://forgetomori.com/2010/fortean/time-traveler-caught-in-museum-photo/
A "portable compact camera" would sound like the Leica introduced in
the 1920 and followed in subsequent years by many other film cameras
that would fit that description. The first ones were solely
mechanical and had no batteries, electronic components or wired
connecetion to anything. Later synchronized flash was developed and
it did have a wire running to a flash bulb, usually fairly large
physically.
It also seems odd the man is not wearing a hat given how ubiquitous
hat-wearing was in that era.
The picture is also on display at the official Canadian museum website
so the picture itself is likely not a hoax and people are interpreting
it in fanciful ways.
Ah, well, it's fun speculating, and finding the two hearing aid
websites along with the interesting inventions including those from WE
was an interesting diversion.
:-)
Wes Leatherock
wesrock@aol.com
wleathus@yahoo.com
Date: Thu, 28 Oct 2010 01:21:46 -0400
From: "Neal McLain" <nmclain@annsgarden.com>
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: Kerry outlines bill to resolve TV disputes
Message-ID: <0f9cbcb1cec84139f267cdc8d3ca7d55.squirrel@email.fatcow.com>
On Oct 26, 9:33 pm, gordonb.ht...@burditt.org (Gordon Burditt) wrote:
> > > I keep seeing ads claiming that Dish has dropped
> > > these channels, and they're about to drop these
> > > November 1, (including, interestingly, a local
> > > channel) go to this web site to find another
> > > provider who still carries them. Obviously, they
> > > are trying to drum up complaints about distributor
> > > dropping these channels.
>
> > If, by "a local channel," you're referring to WNYW (the Fox
> > affiliate in the New York DMA), then I agree: it is interesting.
> > After all, broadcast licensees have legal carriage rights with
> > respect to MVPDs (multichannel video programming distributors)
> > that non-broadcast programmers do not enjoy.
>
> No, I was referring to KDFW channel 4, the Fox affiliate
> in the Dallas/Fort Worth area. This is also the channel
> broadcasting those ads (no surprise here). Does the same
> situation exist with this station?
According to CJR's "Resources" page, KDFW (4) and KDFI (27) are both
owned by Fox Entertainment Group, a wholly-owned subsidiary of News
Corporation. So yes, the same situation exists in Dallas.
http://www.cjr.org/resources/?c=newscorp
Neal McLain
Date: Sat, 30 Oct 2010 16:20:32 -0500
From: bonomi@host122.r-bonomi.com (Robert Bonomi)
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: Happy anniversary cellphone!
Message-ID: <5Oudnf0BSZa9EVHRnZ2dnUVZ_iydnZ2d@posted.nuvoxcommunications>
In article <i9d573$9gs$1@reader1.panix.com>,
danny burstein <dannyb@panix.com> wrote:
>[snip of good stuff]
>
>When did "they" make the decision to get rid
>of the pseudo dial tone? In one of the retrospectives
>at the last anniversary, the ABC (US tv network) shwed
>a clip from an early marketing demo.
Real "dial tone" was a functional requirement on the early 'automatic'
(self-dial) mobile phones.
It only went away when you got phones that (a) could temporarily store the
entire number being called, and (b) transmit 'en bloc' when you hit the
'send' button. Once you got to the point of having to use the 'send'
button to initiate a call, you could start to wean customers away from
reliance on the 'tone' as the 'ok to dial' cue.
-
Those early phones sent the individual digits 'in real time', _as_you_dialed_,
to the head end for processing. Just like with POTS, you were 'off hook'
(and "on the air", tying up the scarce channel) from the time you picked
up the handset, until you hung up.
And, of course, if you go back to the prior generation of mobile phones__
you didn't get dial-tone at all. You picked up the handset and waited
for the operator to acknowledge you. Whereupon you gave your 'ID',
and and the number you wanted to call.
Incidentally, that was the -other- part of the reason for having dial tone
those mobile phones. It told you you did have automatic equipment at the
head end, and did not have to wait for the operator to take your call.
>
>What got my interest was the reporters were
>being walked through the process, with real
>cellular (or at least wireless) phones, which...
>
>... which included a "listen for the dial tone"
That would have been pre-cellular.
Early mobile phone had a very small number of frequencies available
ad the set had to find an open frequency _first_, to open negotiations
with the base station about making a call. Only -after- that did you
get the 'ok to dial your call'.
One of the driving forces behind the implementation of cellular was
that there were getting to be 'too many' users out there. vs the
fixed number of base stations. in 'congested' areas, it could take
a =long= time (tens of minutes, to an hour _or_more_) to luck into an
open channel to place a call on.
Date: Sat, 30 Oct 2010 19:21:38 -0400
From: tlvp <tPlOvUpBErLeLsEs@hotmail.com>
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: dialing from QR bar codes, was 911-only public phone
Message-ID: <op.vlewicowitl47o@acer250.gateway.2wire.net>
On Sun, 12 Sep 2010 18:00:21 -0400, John Levine <johnl@iecc.com> wrote:
>> [1] Yes, the phone's browser will do this even if the number doesn't
>> have an explicit HTML anchor tag (link) on the page! [Probably
>> because AFAIK there isn't a URL "dial://" scheme, is there?]
>
> Silly boy. See RFC 3966, particularly section 8.
>
> R's,
> John
There's another href= value used in WML (the "variant" of HTML that
older cellphones' WAP browsers understand) that also has the effect
of having the phone dial the indicated number. Details must await my
getting to another computer, where my WML experiments reside.
Cheers, -- tlvp
--
Avant de repondre, jeter la poubelle, SVP
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