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Thursday Update
Struggling with a terrible case of poison oak. It will leave small scars. :-( This recent e-mail cheered me up, I am humbled by the many thousands of non-native English speaking people who push through this website, trying to learn:
A Billion Times, Thanks!
Hi Tom,
I've gone thru a lot of sites trying to find a suitable learning Material on Digital stuff for a long time. I worked for Telecom company in Vanuatu South West Pacific (TVL) When I left school I was the Only unlucky one attending a Telecom Technical school in Fiji where the Instructor was a Line Plant technician and was absent 75% of the time, I really have not grasp the basics of radio communication. Since 1989 till this day when I come across you Web page. I can not express our much I feel. Its a feeling of achievement even though I still don't read thru much yet Thanks. I owe you for say....A beginning of a New Start in this Techno Era. Congratulation on your Will to Share your Knowledge which I believe you invested a lot on and yet you share it with the unfortunate once like me.
A lot of Thanks
A reader (name with held)
"Formerly called the New Hebrides, Vanuatu is a Y-shaped chain of 322 tropical islands of volcanic origin situated in Melanesia to the east of Australia. . . "
What else do I do besides neglect this website?
I'm an amateur gold prospector. A friend and I spent a few days recently dredging for gold. Here are some pictures:
http://www.privateline.com/
mining/(internal link)
A great new page on telephone technology
Bookmark this page, save it to your hard drive, and hope the writers keep it current: http://www.epanorama.net/
links/telephone.html (external link)
Excellent technical information on the telephone instrument.
Don Kimberlin writes . . .
The photo caption in your telephone history series (internal link) is incorrect. The large electronic tube is not the single "500 kilowatt valve." It was one of FIFTY-FOUR ten kilowatt tubes operable in parallel to form the transmitter at Hillmorton, near Rugby, in England. When I finish this note, I'll try to find the web link to a local web page from there that has some of the description of the site. That plant exists today and is still on the air, its 8 towers of 800 odd feet being visible for miles around.
The giant transmitter is actually ten radio amplifiers of 100 kilowatts input, 54 kilowatts output each. That, if used together, is called by some one million Watts, based on input; by others, 500 kilowatts or 540 kilowatts based on output. In fact, other than for initial testing, all ten amplifiers were never tied together. Nine of them are used in parallel, excited from a source of the Very Low Frequency of 16.7 kilohertz. with the callsign GBR - which might stand for Great Britain Radio or Great Britain Rugby, or some ways in England say, "Great Bloody Radio."
The original purpose of GBR was to be able to send a telegraphic message to anywhere in the old British Empire at any day or time. It evolved into marine radio use, and since the Cold War, has been used to transmit telegraph to England's nuclear submarines, in the same way the US Navy has several VLF stations for the US subs. The tenth 100 kw in/54 kw out amplifier was the bit used for that first transatlantic radiotelephone link in 1927. It was excited at 60 kilohertz with a single sideband speech exciter to work with its AT&T mate in the States. The AT&T reciever ultimately wound up at Houlton, Maine (which was used in later years as AT&T's Telstar satellite station site), and the Deal Beach transmitter on 55 kilohertz was ultimately replaced with one at RCA's huge transmtting plant at Rocky Point, Long Island. The callsign for the British end was GBT, obviously for Great Britain Telephone or such. I have some docments and the callsigns of the US end somewhere in the clutter here...
When HF (shortwave) radio came into practical use, the VLF link was primarily used as the "backup." Even when the first submarine telephone cable was laid across the Atlantic in 1957, the several shortwave links were retired, but the Rugby-Rocky Point pair were actually kept on the air (but idle) as the final backup - actually in case of nuclear attack that would potentially make render both cables and shortwave useless. It wasn't till there were several cables and satellites in use that the 60 kHz/55 kHz link was retired. In England, the 60 kHz operation's callsign was changed to MSF, and it became England's standard time and frequency reference transmitter, which it is to this day. Over the years, the 1927 transmitters have certainly been replaced, but the British Post Office maintains a security cloak over what the GBR transmitter is today. They have told that the MSF transmitter has been replaced a couple of times, and we can certainly expect similar change has been made to GBR. Here's the web page, which isn't that well written, for GBR.
http://62.32.51.17:8033/Radio_masts/ (external link) May now be dead
There's a whole lot more to the early days of telecommunications. I have written a number of vignettes of the monsters of early radio, which I call "Jurassic Telecommunications." By and large, like the dinosaurs, it grew from cricket chirps into beasts of 100 or even 300 kilowatts, and the final bit were a few megawatt monsters like GBR. One of the more interesting ones is the French megawatt spark monster that Blackjack Pershing ordered in WWI, at a Bordeaux location called Croix d'Hins. It was intended as a backup link across the Atlantic in case the Germans cut the transatlantic telegraph cables. Its callsign was merely LY and operated on VLF of 12.7 kHz. It didn't last long after the war, because when radio began to develop, it was found to cause so much interference that it had to be abandoned! Here's a page about it:
http://www.radio-ecouteur.net/croixhins.htm (external link, now dead)
And, here are a couple of links about a third monster, Alexanderson's Alternator, of which one plant is still maintained at Grimeton, Sweden, callsign SAQ on 17.2 kHz:
http://www.telemuseum.se/historia/alex/ (external link, now dead)
1.html http://www.telemuseum.se/grimeton/defaulte.html (link now dead)
There were (and indeed, still are) many "footprints of the dinosaurs" of radio among us. Just last month, I was in Florida finding the concrete tower base of the first - ever AM broadcast "directional antenna" in the world. I hope you find all this interesting. I add to the database as I can. You can see some of it in the Archives section of: www.oldradio.com (external link)
Cheers, Don Chamberlin
Getting Twisted; The Return of Cowboy Frank
Tom:
I'm confused about aerial drop wires. On your outside plant page http://www.privateline.com/OSP/No.html (internal link) you write: "Drop wires can be thirty feet long or thousands of feet in length. They contain several twisted pair, only the oldest drops containing a single twisted pair." The only kind I have ever seen is the single-pair parallel-conductor steel-core drop wire that has been on my house since at least 1975. Is it shielded? What does it use for a strength element? When was it first introduced?
Dear Reader:
Thanks for the e-mail. Cowboy Frank responds to your question:
"When I worked for Ma Bell, in 1973, our aerial drops were simple copper clad steel conductors with no twisting. The entire cable had a rubber (or plastic) and fabric insulation that was actually molded onto the conductors rather than having an outer jacket. (always made for a headache to remove the insulation without the proper tools) I think this is the type cable the person below is asking about. These (or something similar) are still quite common up on poles but I don't know if it still manufactured for new installations. The strength comes from the steel wire itself. I remember the same kind of drops as early as 1951 as the house I was born in (1952) had this type of drop. (even though it wasn't a Bell system company)"
"The only reason for twisting the pair is to prevent crosstalk between the pairs, so when there is only a single pair, they seldom go to the expense of twisting which would then necessitates the inclusion of an embedded "strand" (the heavy steel wire used to support cables). I don't recall having ever seen any Phone drop with an embedded strand, but I can understand the reason the person below would use a zip cord style description for his drop (it does look a bit like that but doesn't pull apart easily. Embedded strand is common for TV cable drops however."
"In 1973 they did have multi pair aerial drops used occasionally for multi family residences or small businesses. I seem to remember 6, 12 and 16 pair cables, but not sure about the 16 pair. It's been too long. At that time there was no included strand. If the cable was under about 50 feet, C&P phone company just used the general strength of the cable and it's outer jacket for support. If it was over 50 feet then they would sometimes run a standard single pair copper-clad steel drop and tie the multi pair to that. If the local supervisor was a stickler for neatness (as was frequently the case with Ma Bell) they would run a single conductor 10 gauge insulated steel wire, or a small gauge strand, and have the drop neatly twined (or what ever the correct term was which I can't remember) with the wrapped small wire used to tie big cables to the main strand. (I was actually never in that specific department so didn't learn the terminologies)"
"Shielding on overhead wires is not very common. Shielding is mainly used for either physical cable protection or to prevent wiretapping such as in the Pentagon. We use to see an occasional phone with an armored cord come in from the Pentagon. The cord looked somewhat like the new oven thermometers that are becoming common, but a bit thicker. Some underground drops are shielded mainly to protect them from rodents, and gardeners with shovels. I believe most of the newer underground drops are abandoning the shielding due to expense. I guess they figure it is cheaper to send our a repairman than to add the extra protection. Or maybe it turned out the cables got cut anyway. Been a long time since I was involved in that."
"In your e-mail you sked about a rubber covered box about 7 feet up the pole. Many times an installer would mount a connector block (splice joint) on the pole to simplify the installation of the drop. Especially if the drop was running down several poles before jumping across the street or to the house. It was easer to run the drop to that point and make a splice than to try to deal with a long drop and having to stop traffic while getting it across the street. I have seen some places where this appeared to be the standard practice for some reason. Every pole had several splice blocks on it. Really looked messy. This was more common on non-Ma Bell systems. Ma Bell was usually a stickler for neatness and didn't like such practices."
Visit Cowboy Franks' site soon:
http://nps-vip.net/ (external link)
Under A Telephone Pole by Carl Sandburg (1916)
Hmm. PhoneTel http://phonetel.com/html/welcome.html (external link) says that the AnsaFone in 1960 became "the first commercially viable Telephone Answering Device offered for sale in the United States." The key phrase is for sale. The Bell System leased equipment to customers, it did not sell their products. Thus, while the AnsaFone may have been sold first, it was not the first answering machine. According to Amos Joel, the Bell System started work on "machine type service" in 1950, with trials in New York and Cleveland. Western Electric later produced for the Bell System the first true answering machine, the WE1A, using magnetic coated drums.
The AnsaFone pictured below is from the Roseville Telephone Company telephone museum: http://www.rosevilletelephone.com/museum/ in Roseville, California. Click here or on photo to enlarge. Roseville always changes their URLS without telling anyone. I'm giving up linking to them.
The AnsaFone has U.S. Patent Number 3,376,390. Look up the 12 page patent document by going to the U.S. Patent and Trademark office: http://www.uspto.gov (external link)
