On Sun, 29 Jun 2003, Ben A L Jemmett wrote: > > I'm not sure if a balun would help; they're available with RJ45 on one side > and BNC the other, and I think they're suitable for Ethernet. My first
Wouldn't that be the cat's meow? Physically they look ideal: rj45 jack on one end, bnc male coupling on the other. And they're small and not too expensive (in the $5 range). But the thing that confuses me is that there are other things advertised to convert 10 base2 to 10 baseT for 10 to 20 times the cost. Here's an example, snipped from the 'net: ------------BEGIN FIRST EXCERPT FROM WEB--------------------------- The FlexPointTM 10T/2 is a member of the modular FlexPoint converter product family. The FlexPoint product family supports the IEEE 802.3 standard and provides an extensive range of connectivity options across different media. The FlexPoint 10T/2 is a 10Base-T to 10Base-2 converter that converts between twisted pair (UTP) and coax LANs and joins their collision domains. The FlexPoint 10T/2 facilitates the connection of a coax segment to a 10Base-T hub. When using a pair of FlexPoint 10T/2 converters back to back, they connect between two 10Base-T hubs via coax. On the UTP side, the FlexPoint 10T/2 uses a modular EIA/TIA 568 RJ45 connector that supports categories 3, 4 or 5 wiring and connects to distances up to 100 m (328 ft.). The FlexPoint 10T/2 detects and corrects wiring polarity reversals, and features a crossover switch that facilitates a straight-through cable connection to a workstation or a hub and eliminates the need for a crossed cable. On the coax side, the FlexPoint 10T/2 utilizes a BNC connector and supports a 50 ohm cable and distances of up to 185 m (606 ft.). Per IEEE 802.3 standard, up to 30 workstations can be attached to the coax segment. The FlexPoint 10T/2 features a convenient and cost-effective cable termination via a termination switch and a built-in termination element. The FlexPoint 10T/2 provides diagnostic data through LED indicators that assist in network installation and maintenance. The LEDs report power availability, collisions and jabber, the detection of a device on the UTP side (Link), data being received (Rx) on the coax or UTP sides, and polarity reversal detection and correction on the UTP side. The FlexPoint offers several mounting options. The converter can be mounted stand-alone utilizing optional wall-mounting hardware. It can also be rack-mounted using a 5-unit shelf or in a high-density, 14-unit, dual-power-redundant Powered Chassis. The FlexPoint 10T/2 is completely software-independent and software-transparent; it requires no software setup. -----------------------END FIRST EXCERPT FROM WEB--------------------------- This thing actually sounds more like what I understand a "bridge" to be: for joining together LAN's (in this case a coax LAN with a UTP LAN). Do I really need something like this to use this card I've found? For balance, here's a description of one of the Balun's I found on the web: ----------BEGIN SECOND WEB EXCERPT------------------------- BALUNS Converts costly inflexible coax cable to industry standard UTP. Aids in avoiding the expense of running costly and inflexible coaxial, dual coax or twin-ax cabling. HERME BALUNS HB-100-1 3270 MALE coax to RJ45 PINS 4 & 5 HB-100-3 3270 MALE coax to RJ45 PINS 3 & 4 ---------------END SECOND WEB EXCERPT----------------------------- I don't quite understand the part about the pins, and why it lists only 2 pins in each case, while UTP has 8 wires. Interestingly, I found a site that sells an adaptor for this card that goes straight from the card to an rj45 plug (with some little cylindery thing in the line there - see the image at http://www.thesupplynet.com/productDetail.cfm?prodID=857 if interested). They're asking $50 for it: who in their right mind would pay that?! I bought the card for $5! Hell, if I wait for another sale to come along, I can pick up 5 PCMCIA NIC's - 10/100 speed at that - for the price of that cable plus the card's cost. No, that's definitely *not* the way to go. But the rj45 cable got me thinking of something I'd earlier considered - splicing into the cable and trying to hack in a UTP cable. With the limted understanding I have of the card and of circuitry in general, I'm reluctant to do this though. The card has 22 pins where the cable plugs in: I can't logically reduce that to the 8 wires typically found in UTP. Anyone have any ideas on that? Thanks, James To unsubscribe from SURVPC send a message to [EMAIL PROTECTED] with unsubscribe SURVPC in the body of the message. Also, trim this footer from any quoted replies. More info can be found at; http://www.softcon.com/archives/SURVPC.html
