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Message Digest Volume 28 : Issue 43 : "text" Format Messages in this Issue: Re: Surge Protection Re: TTY 33 and 35 case and cover composition? ====== 27 years of TELECOM Digest -- Founded August 21, 1981 ====== Telecom and VOIP (Voice over Internet Protocol) Digest for the Internet. All contents here are copyrighted by Patrick Townson and the individual writers/correspondents. Articles may be used in other journals or newsgroups, provided the writer's name and the Digest are included in the fair use quote. By using -any name or email address- included herein for -any- reason other than responding to an article herein, you agree to pay a hundred dollars to the recipients of the email. =========================== Addresses herein are not to be added to any mailing list, nor to be sold or given away without explicit written consent. Chain letters, viruses, porn, spam, and miscellaneous junk are definitely unwelcome. We must fight spam for the same reason we fight crime: not because we are naive enough to believe that we will ever stamp it out, but because we do not want the kind of world that results when no one stands against crime. Geoffrey Welsh =========================== See the bottom of this issue for subscription and archive details and the name of our lawyer, and other stuff of interest. ---------------------------------------------------------------------- Date: Wed, 11 Feb 2009 04:37:18 -0600 From: "GlowingBlueMist" <nobody@nowhere.com> To: redacted@invalid.telecom.csail.mit.edu Subject: Re: Surge Protection Message-ID: <4992aa51$0$57677$892e0abb@auth.newsreader.octanews.com> <4netpost@gmail.com> wrote in message news:edadf13a-6e38-46f7-ad83-64b88f211463@t13g2000yqc.googlegroups.com... >I have a need to add some surge protect a telephone system. > > I need the surge protection on the incoming circuits, right at the > demark point. I have several lines including POTS voice lines, POTS > dial in modem lines, VDSL, ADSL, and T1 circuits. Is there a surge > protector that will protect all of the above lines without degrading > performance? > Check with Mike Sandman's web pages. I'm sure he has what you want in there somewhere, or send him an email. His web page and catalog can be found at http://www.sandman.com/ ------------------------------ Date: Wed, 11 Feb 2009 06:54:03 -0800 (PST) From: hancock4@bbs.cpcn.com To: redacted@invalid.telecom.csail.mit.edu Subject: Re: TTY 33 and 35 case and cover composition? Message-ID: <2b9d832c-9a05-4bc9-ba4b-f202085b4288@x9g2000yqk.googlegroups.com> On Feb 11, 12:51 am, Michael Grigoni <michael.grig...@cybertheque.org> wrote: > > # These are the hardcopy Teletypes from before AT&T bought the > > # company, clattering electromechanical dinosaurs in Bakelite > > # cases that printed on pulpy yellow roll paper.  If you remember > > # these you go back a ways. Teletype-branded VDTs are listed in > > # the AT&T section. > I replied to the list that I was unaware of any Bakelite cased 33s > or 35s and that the covers were made from a thermoplastic for the > 33.  I received a reply that someone wondered if any 'hardened' > versions had Bakelite cases. As an aside, AT&T (through Western Electric) owned Teletype for many years, I believe since the 1930s. I believe the 'bodies' of Teletypes were steel with a glass insert. The model 33 had a liftable cover which I suspect was plastic. How does one differentiate between actual Bakelite and plain plastic? While we're on the subject, was the model 33 impact impression adjustable? That is, how many good quality carbons could be made? Many schools used model 33s to each comp sci in the 1960s/70s. Could a school have used a spirit "ditto" master form (the kind with the heavy blue carbon sheet underneath, not mimeograph) to duplicate a terminal session? You need to press hard on those to get a clear copy, and even then the results were faint. [But before cheap Xerox machines, that was the cheapest way for short runs (under 50 copies). Long runs required the mimeograph machine which meant cutting a stencil with a typewriter; they were messy! The spirit duplicator used a fluid to copy off the backside of the master, the mimeograph bled the ink through the cut stencil.] I got the sense that TTYs did not have a hard impact impression. We always used the pulp paper (for us, they gave us newsprint). When the TTY ribbon was too faint, I took them home and got plenty of more use of them on a regular manual typewriter. ***** Moderator's Note ***** The Model 33 case was plastic, not Bakelite, which was too prone to chipping and cracking to be used in a high-vibration environment such as a Teletype machine. Earlier machine, such as the venerable Model 15, had metal cabinets. The Model 32/33 impression strength could be adjusted only slightly, but it was pretty high to begin with: carbon forms with up to two copies could be used without trouble. The problem with carbon forms was not the impression depth, but the "shoulder" impressions made by adjacent characters on the typewheel used by the Model 32/33. The Model 28/35, which had a type pallet with individually-struck slugs for each character, could be used for thicker forms, with more copies. Many schools _DID_ use the Model 33 as a terminal during the start of the computer revolution, and that gave the 33 an undeserved reputation for unreliability. School administrators, who weren't expected to know any better, and system salesmen, who did know better, economized on the terminals to close sales. The Model 32/33, however, wasn't designed for service as a computer terminal, but rather for use in TELEX and TWX networks: it was rated (IIRC) for 1500 "shaft" hours before major overhaul. In TELEX or TWX service, that translated to years of reliability. Computer users, especially children in computer labs, placed much higher demands on the machines than they were designed to serve. Bill Horne Temporary Moderator ------------------------------ TELECOM Digest is an electronic journal devoted mostly to telecom- munications topics. It is circulated anywhere there is email, in addition to Usenet, where it appears as the moderated newsgroup 'comp.dcom.telecom'. TELECOM Digest is a not-for-profit, mostly non-commercial educational service offered to the Internet by Patrick Townson. All the contents of the Digest are compilation-copyrighted. You may reprint articles in some other media on an occasional basis, but please attribute my work and that of the original author. The Telecom Digest is currently being moderated by Bill Horne while Pat Townson recovers from a stroke. Contact information: Bill Horne Telecom Digest 43 Deerfield Road Sharon MA 02067-2301 781-784-7287 bill at horne dot net Subscribe: telecom-request@telecom-digest.org?body=subscribe telecom Unsubscribe: mailto:telecom-request@telecom-digest.org?body=unsubscribe telecom This Digest is the oldest continuing e-journal about telecomm- unications on the Internet, having been founded in August, 1981 and published continuously since then. Our archives are available for your review/research. We believe we are the oldest e-zine/mailing list on the internet in any category! URL information: http://telecom-digest.org Anonymous FTP: mirror.lcs.mit.edu/telecom-archives/archives/ (or use our mirror site: ftp.epix.net/pub/telecom-archives) RSS Syndication of TELECOM Digest: http://telecom-digest.org/rss.html For syndication examples see http://feeds.feedburner.com/telecomDigest Copyright (C) 2008 TELECOM Digest. All rights reserved. Our attorney is Bill Levant, of Blue Bell, PA. ************************ --------------------------------------------------------------- Finally, the Digest is funded by gifts from generous readers such as yourself who provide funding in amounts deemed appropriate. Your help is important and appreciated. A suggested donation of fifty dollars per year per reader is considered appropriate. See our address above. Please make at least a single donation to cover the cost of processing your name to the mailing list. All opinions expressed herein are deemed to be those of the author. Any organizations listed are for identification purposes only and messages should not be considered any official expression by the organization. End of The Telecom digest (2 messages) ******************************