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The Telecom Digest for September 13, 2011
Volume 30 : Issue 229 : "text" Format
====== 30 years of TELECOM Digest -- Founded August 21, 1981 ======
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Telecom and VOIP (Voice over Internet Protocol) Digest for the
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See the bottom of this issue for subscription and archive details
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Date: Mon, 12 Sep 2011 01:27:26 -0700 (PDT)
From: mattrix <mattrix3@gmail.VALID-IF-THIS-IS-ELIDED.com>
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: ANCIENT telephone transmission
Message-ID: <d3cff414-27e6-49e3-b44f-27d00c07becd@s2g2000prm.googlegroups.com>
Thanks HAncock4, I'll try to track those references down.
>I don't know what "historians" told you that, but I suspect that they "are
>full of it".
>....
>So I seriously doubt that firstly they [long lines] were "Common",
Perhaps I should have qualified my original statements.
"Self proclaimed historians", not neccessarily technicaly minded, who
state that something happened but not how; and who dont always
distinguish between telphone/telegraph or a single cable with 12 lines
as opposed to a single wire with 12 conversations.
"not uncommon" instead of common. eg,
- 1884 New York to Boston ~ 200 miles
- 1891 London to Paris ~200 miles, but links anyone in UK that can
access London to anyone in Europe that can access Paris
- 1892 New York to Chicago ~700 miles (1000 miles cable -ny times
October 19, 1892) and consequently Chicago to Boston.
....
The suggestion seems to be that you just need to use heavier wires
(more surface area?), or did they need to do more than this?
>or that they used FDM without active equipment.
I agree and hence my question. I can't find the FDM reference :
( However, I try not to underestimate the ingenuity of engineers of
those days. Radio telegraphy was developed in the 1890's, and radio
transmission of audio in the 1900's, all with no active components.
(both from wikipaedea) I just don't think like they did.
I've had a few more days to ponder this, Actually they could have used
an electro-mechanical device to convert voice signals to a varying
resistance. This in serries with an AC signal could be used as a
modulator (AM). It could even be used for amplification, if the
electro-mechanical device consumes 0.5W to go from extreme to extreme
but the AC signal it modulates could deliver 50W.
Any one know what they actually did?
I'm still not sure how they would recover those conversations. A heap
of passive serial tuned circuits, all in parallel seems unworkable.
matt
Date: 12 Sep 2011 09:56:03 -0400
From: kludge@panix.com (Scott Dorsey)
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: ANCIENT telephone transmission
Message-ID: <j4l31j$pbh$1@panix2.panix.com>
mattrix <mattrix3.remove-this@and-this-too.gmail.com> wrote:
>
>The historians tell me that 600 mile lines were common, and that they
>carried multiple conversations using Frequency Division Multiplexing.
No.
You carry multiple conversations in a pre-electronic system through using
phantom and simplex circuits. You can take two pairs and get three lines
across it... two differential signals across each pair and then a common
mode signal between the two. But that's the degree to which you can go.
Time division and frequency division multiplexing WERE used for telegraph
circuits, using mechanical distributors and mechanical tuned reeds. But
not for telephone.
>- Without the afore mentioned technology, how do you modulate and
> combine the conversations?
You don't.
>- Without amplifiers, how do you handle attenuation?
By using widely spaced pairs to reduce shunt capacitance, using very large
diameter wire to reduce series resistance, using loading coils, and shouting
very loudly into the telephone.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
Date: Mon, 12 Sep 2011 17:21:24 -0400
From: Eric Tappert <e.tappert.spamnot@worldnet.att.net>
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: ANCIENT telephone transmission
Message-ID: <9qts67t2mdu8gndum18gcvksjinab0chhs@4ax.com>
On 12 Sep 2011 09:56:03 -0400, kludge@panix.com (Scott Dorsey) wrote:
>mattrix <mattrix3.remove-this@and-this-too.gmail.com> wrote:
>>
>>The historians tell me that 600 mile lines were common, and that they
>>carried multiple conversations using Frequency Division Multiplexing.
>
>No.
>
>You carry multiple conversations in a pre-electronic system through using
>phantom and simplex circuits. You can take two pairs and get three lines
>across it... two differential signals across each pair and then a common
>mode signal between the two. But that's the degree to which you can go.
>
>Time division and frequency division multiplexing WERE used for telegraph
>circuits, using mechanical distributors and mechanical tuned reeds. But
>not for telephone.
>
>>- Without the afore mentioned technology, how do you modulate and
>> combine the conversations?
>
>You don't.
>
>>- Without amplifiers, how do you handle attenuation?
>
>By using widely spaced pairs to reduce shunt capacitance, using very large
>diameter wire to reduce series resistance, using loading coils, and shouting
>very loudly into the telephone.
>--scott
Phantom circuits were used in actual service and additional schemes
were not, however, they were investigated and documented. For
example, a Ghost circuit was a simplex circuit over two Phantom
circuits and a Wrath circuit was a Phantom circuit over two Ghost
circuits. Ghost and Wrath circuits were impractical as the balance
required could not be achieved in the "real" world outside of the
laboratory. Neat stuff, though...
ET
Date: Mon, 12 Sep 2011 16:52:59 -0700 (PDT)
From: Wes Leatherock <wleathus@yahoo.com>
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: ANCIENT telephone transmission
Message-ID: <1315871579.11397.YahooMailClassic@web111721.mail.gq1.yahoo.com>
--- On Mon, 9/12/11, Scott Dorsey <kludge@panix.com> wrote:
[snip]
>> - Without amplifiers, how do you handle attenuation?
>
> By using widely spaced pairs to reduce shunt capacitance, using very
> large diameter wire to reduce series resistance, using loading
> coils, and shouting very loudly into the telephone.
> --scott
I have heard, and it seems to have been a not-rare practice, that an
operator at an intermediate point was sometimes enlisted to relay,
shouting back and forth between the customers.
Wes Leatherock
wleathus@yahoo.com
wesrock@aol.com
Date: Sun, 11 Sep 2011 20:20:20 -0700
From: Andrew Carey <carey@ar-ballbat.VALID-IF-THIS-IS-ELIDED.org>
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: Fuse Panel Recommendation
Message-ID: <AC2FA799-A486-46BC-869F-8F9A1D43E911@ar-ballbat.VALID-IF-THIS-IS-ELIDED.org>
"W" <withheld@invalid.telecom-digest.org> wrote:
> Can someone recommend a -48V DC fuse panel for a telecom rack that
> would meet two requirements: - let us manually configure the fuse or
> circuit breaker for each piece of equipment, up to 30A per box (most
> equipment would be at or under 20A) - show a spot reading of the
> total amps in current use across all devices that go through the
> fuse panel that are currently powered on
Try http://www.lineagepower.com/?page_id=291
I haven't used that particular piece of equipment but Lineage Power/GE
Energy (former Lucent power business) has a pretty good reputation in
general. PECO II has a similar product but with two breaker outputs or
1 breaker and 10 GMT fuses outputs.
Date: Mon, 12 Sep 2011 17:54:51 +0000 (UTC)
From: Joseph Pine <josephpine@invalid.invalid>
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: area code named beer
Message-ID: <Xns9F5E836DA3E68nomailnomailorg@88.198.244.100>
Neal McLain <nmclain@annsgarden.com> wrote in
news:d004cb5b-0868-4ad9-af74-171e312a1968@x12g2000yql.googlegroups.com:
[snip]
>> I'd like to know the last new name that was assigned to an
>> exchange. Probably done in the 1960s. In some places, the
>> transition was done slowly, for example, there was a TUrner 4 (884),
>> but when 885 was opened, it was given 885 instead of TU 5); lots of
>> examples like that (ORchard 3, 6, 7 were joined by 671).
>
> Lisa or Jeff <hancock4@bbs.cpcn.com in Message-ID:
> <bcc40aff-ddfe-42d1- a4c7-d8296adabd66@d32g2000yqa.googlegroups.com>
> wrote:
>
>> When the second digit of an exchange was 9, some places
>> used Y, as in HYacinth, HYatt, CYpress, LYric....
>> (One community in NJ had SWinburne, named for an old
>> poet.)
>
> Back when it was part of 713, Brazoria Telephone Company (Brazoria,
> Texas) used SWift for its one and only NNX code, 798.
>
>> lots of examples like that (ORchard 3, 6, 7 were joined
>> by 671).
>
> In Skokie, Illinois, ORchard even included Orchard 0. According to a
> second-hand story, Director Assistance operators recited it as "oh are
> oh."
>
> Neal McLain
>
>
The Telephone EXchange Name Project website has a lot of material on
the subject of exchange names, which might be of interest.
http://ourwebhome.com/TENP/TENproject.html
Date: Mon, 12 Sep 2011 16:44:55 -0700 (PDT)
From: Wes Leatherock <wleathus@yahoo.com>
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: area code named beer
Message-ID: <1315871095.30374.YahooMailClassic@web111717.mail.gq1.yahoo.com>
--- On Mon, 9/12/11, Joseph Pine <josephpine@invalid.invalid> wrote:
>> Lisa or Jeff <hancock4@bbs.cpcn.com> wrote
>> in Message-ID: <bcc40aff-ddfe-42d1- a4c7-d8296adabd66@d32g2000yqa.googlegroups.com>
>>> When the second digit of an exchange was 9, some places used Y, as
>>> in HYacinth, HYatt, CYpress, LYric....
>>> (One community in NJ had SWinburne, named for an old poet.)
The approved Bell System list of names specifically excluded YUkon,
since they felt too many customers would dial UK. However, I remember
YUkon being used some place, perhaps Dallas.
Wes Leatherock
wleathus@yahoo.com
wesrock@aol.com
Date: Mon, 12 Sep 2011 10:39:43 -0700 (PDT)
From: HAncock4 <withheld@invalid.telecom-digest.org>
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: AT&T advert from 1970s re: World Trace Center
Message-ID: <e3551c7e-e4f6-4b42-adc8-0c2672ba4938@fi7g2000vbb.googlegroups.com>
On Sep 11, 6:55~pm, danny burstein <dan...@panix.com> wrote:
> - in the website's discussion, they comment that "None of AT&T's
> employees were hurt in the attacks." That's kind of true, but some
> Verizon personnel were killed.
Were any secondary or primary central offices impacted in the WTC area
by the attack that affected telephone service? I know cell phones
were overwhelmed, but I'm not sure about the impact on land lines
(given the calamity, they may have been overwhelmed, too.)
I know some people who until that time did not have cell phones.
After 9/11 they got them for emergencies.
Date: Mon, 12 Sep 2011 15:38:28 -0700
From: Steven <diespammers@ikillspammers.com>
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: AT&T advert from 1970s re: World Trace Center
Message-ID: <j4m1l4$snq$1@dont-email.me>
On 9/12/11 10:39 AM, HAncock4 wrote:
> On Sep 11, 6:55 pm, danny burstein<dan...@panix.com> wrote:
>
>> - in the website's discussion, they comment that "None of AT&T's
>> employees were hurt in the attacks." That's kind of true, but some
>> Verizon personnel were killed.
>
> Were any secondary or primary central offices impacted in the WTC area
> by the attack that affected telephone service? I know cell phones
> were overwhelmed, but I'm not sure about the impact on land lines
> (given the calamity, they may have been overwhelmed, too.)
>
> I know some people who until that time did not have cell phones.
> After 9/11 they got them for emergencies.
>
There was a Verizon CO down the street that had its windows and part of a
wall blown out.
--
The only good spammer is a dead one!! Have you hunted one down today?
(c) 2011 I Kill Spammers, Inc. A Rot in Hell Co.
Date: Mon, 12 Sep 2011 16:39:37 -0700 (PDT)
From: Wes Leatherock <wleathus@yahoo.com>
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: AT&T advert from 1970s re: World Trace Center
Message-ID: <1315870777.53017.YahooMailClassic@web111710.mail.gq1.yahoo.com>
--- On Mon, 9/12/11, HAncock4 <withheld@invalid.telecom-digest.org> wrote:
>> - in the website's discussion, they comment that "None of AT&T's
>> employees were hurt in the attacks." That's kind of true, but some
>> Verizon personnel were killed.
The reference was to AT&T employees, not to phone employees in general.
> Were any secondary or primary central offices impacted in the WTC
> area by the attack that affected telephone service?~ I know cell
> phones were overwhelmed, but I'm not sure about the impact on land
> lines (given the calamity, they may have been overwhelmed, too.)
Weren't a number of C.O's serving customers in the WTC on several
floors of= the WTC? Surely they were destroyed, too.
Wes Leatherock
wleathus@yahoo.com
wesrock@aol.com
Date: Mon, 12 Sep 2011 11:52:29 -0400
From: tlvp <mPiOsUcB.EtLlLvEp@att.net>
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: Email spam getting to me
Message-ID: <w5t2hgfq82f4$.rurfjwq4nwf$.dlg@40tude.net>
On Wed, 24 Aug 2011 08:32:06 -0700 (PDT), daryl.gibson@gmail.com wrote:
> On Aug 23, 1:16~~pm, AES <sieg...@stanford.edu> wrote:
>
>> The email spam problem on my university email account (which is the
>> only personal email account I have or ever want to have) is at this
>> point really getting to me. ~~
>
> May I suggest you get a Gmail account and ...
I can confirm that Gmail's spam filters are preternaturally effective.
Over several years, the three Fmail accounts I have dominion over have
seen precisely one mis-characterized email -- a non-spam deemed spam
-- and that was it.
There's a collateral issue, though, of whether you want google sifting
through your university emails for interesting Search-relevant details.
Cheers, -- tlvp
--
Avant de repondre, jeter la poubelle, SVP.
***** Moderator's Note *****
I'm closing this thread: the subject is too far outside the Digest's
core.
Bill Horne
Moderator
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