jlangri@relay.nswc.navy.mil (03/19/91)
A friend of mine will be heading for Scotland next month and wants to take a laptop pc w/modem. I'm sure he can use a voltage adapter to charge the battery (I'm not real sure he would want to use the pc directly off the adapter), but what type of hookup will he need to connect his modem to the phone system there?
julian%bongo.UUCP@nosc.mil (Julian Macassey) (03/26/91)
In article <telecom11.218.6@eecs.nwu.edu> jlangri@relay.nswc.navy.mil writes: X-Telecom-Digest: Volume 11, Issue 218, Message 6 of 12 > A friend of mine will be heading for Scotland next month and wants > to take a laptop pc w/modem. What type of hookup will he need > to connect his modem to the phone system there? This is one of those questions asked here so often I am surprised the modem, FAX and phone manufacturers don't put it in their manuals. First of all, Europe - yes, even Scotland - uses CCITT modem standards. Here in the US we use BELL mostly with CCITT V32 etc. becoming more popular. So if your friend wants to log into local systems, he may need to switch his modem over. If he is calling back to the US. No problem. Now in many parts of the U.K. Touch Tone dialing is available, so that can be tested with a test dial. If not, pulse will work fine. Now the mechanical stuff: For the international, works anywhere solution, you will need a modular cord with spade lugs on the end. Telephone equipment stores, including AT&T phones stores (The Death Star Store), carry these. You plug the modular part in the modem or phone and the spade lugs screw down to your local terminal block. On British Telecom Jacks, that would be terminals 2 and 5. In the U.K. you can bring in a modular cord and cut the plug off one end. Take it to an "Electrical shop" where they will terminate the spare end of your modular cord with a British Telecom style jack plug. Tell the man in the shop that the two center wires in your Yank phone line are the ones he wants. Yes, why hasn't the world adopted the wonderful AT&T modular jack? It is pretty nifty, reliable and cheap. Some countries have phone jacks that look like they can handle 20A at 220V. Here is the document on Brit Jacks: British Telecom Auxiliary Jack Wiring British phones have 3 wires. There are two wires A & B (Tip & Ring) coming into a house. There is no protector. In the primary jack in the house is a 2 uF capacitor. On the end of this cap is the third wire. The AC ringing signal is fed to the phone on this wire and its DC counterpart. See diagram: ----| |------O (3) | | (A) O----------------------O (2) (B) O----------------------O (5) Note: The Numbers in the diagram are the numbers engraved on the jack terminals. If the phone rings continuously, reverse 2 and 5. The ringer is fed by AC current on pins 3 and 5. BT consider the A terminal to be ground. B is measured as 45 to 50 volts above ground. Wiring Colour Codes: The standard inside wire is classic "3 pair". A jack is wired as follows: Pin # Wire colour 2 Blue/White 3 Orange/White 4 White/Orange 5 White/Blue END Julian Macassey, n6are julian@bongo.info.com ucla-an!denwa!bongo!julian 742 1/2 North Hayworth Avenue Hollywood CA 90046-7142 voice (213) 653-4495
peter@taronga.hackercorp.com (Peter da Silva) (03/27/91)
One problem I have with US-style phone jacks is that little plastic spring that keeps the plug in the socket is always breaking off. I've bought a crimping tool just so I can replace the buggers without throwing out twenty feet of perfectly good cord. (peter@taronga.uucp.ferranti.com)