[comp.dcom.lans] thin-net and thick?

smiller@umn-cs.CS.UMN.EDU (Steven M. Miller) (01/16/90)

We have 1 single HP box that has only a thin ethernet board.
However our net is a combination of thick and twisted pair.

Question:  What is the quickest, cheapest, easiest way to hook that
machine into the network?

Thanks,

Steven
-- 



			-Steven M. Miller, U of MN

haas@cs.utah.edu (Walt Haas) (01/16/90)

In article <18189@umn-cs.CS.UMN.EDU> smiller@umn-cs.CS.UMN.EDU (Steven M. Miller) writes:
>
>We have 1 single HP box that has only a thin ethernet board.
>However our net is a combination of thick and twisted pair.
>
>Question:  What is the quickest, cheapest, easiest way to hook that
>machine into the network?

When we were faced with this situation, the best I could come up with was to
buy a thinnet transceiver and hang it off a 15 pin on the Starlan hub.
Somewhat less than elegant, but it works fine.

Cheers  -- Walt Haas    haas@cs.utah.edu    utah-cs!haas

mrm@sceard.Sceard.COM (M.R.Murphy) (01/17/90)

In article <1990Jan15.205330.16319@hellgate.utah.edu> haas@cs.utah.edu (Walt Haas) writes:
>In article <18189@umn-cs.CS.UMN.EDU> smiller@umn-cs.CS.UMN.EDU (Steven M. Miller) writes:
>>
>>We have 1 single HP box that has only a thin ethernet board.
>>However our net is a combination of thick and twisted pair.
>>
>>Question:  What is the quickest, cheapest, easiest way to hook that
>>machine into the network?
>
>When we were faced with this situation, the best I could come up with was to
>buy a thinnet transceiver and hang it off a 15 pin on the Starlan hub.
>Somewhat less than elegant, but it works fine.
>
>Cheers  -- Walt Haas    haas@cs.utah.edu    utah-cs!haas

Use 2 type-N to BNC adaptors and a BNC Tee. You will also need 2 type N
connectors for your thick wire to allow you to connect to the type-N
to BNC. This will shorten your allowable (under the rules) cable length
from that for an all thick network. However, it will work. While you
are cutting, soldering, and cursing, your net will be down.
You can also take a short length of 75 ohm cable (or 52 ohm), correctly
attach a BNC, strip the other end of the cable, cut your thick cable, join
the three center conductors with a glob of solder, wrap the shield braids
together so's they don't touch the center conductor and tape the whole thing
up with masking tape. It will work, with the restriction that it will severely
limit the length of your network, won't take physical abuse, won't stand up
to moisture... Even coat hangers separated by an air gap will work for a
limited distance. 75 ohm coax will work. 52 ohm coax will work. Terminators
matter. The maximum network length is affected. There are probably 20
reasonable ways to do what you want to do, but the cheapest clean way is
probably the type-N to BNC.

Those who disagree with this rather sloppy description of jiggling electrons in
short wires are directed to the excellent technical documentation supplied
for free by Ethernet chipset manufacturers.  :-)
--
Mike Murphy  Sceard Systems, Inc.  544 South Pacific St. San Marcos, CA  92069
mrm@Sceard.COM        {hp-sdd,nosc,ucsd,uunet}!sceard!mrm      +1 619 471 0657

John_Robert_Breeden@cup.portal.com (01/17/90)

>
>We have 1 single HP box that has only a thin ethernet board.
>However our net is a combination of thick and twisted pair.
>
>Question:  What is the quickest, cheapest, easiest way to hook that
>machine into the network?
>
>Thanks,
>
>Steven
>-- 

Assuming that your TP complies to the 10baseT draft - 

Most thinnet cards also have a AUI port on them (DB15 connector), if so, just
use a TP AUI adapter (TP to AUI, then an AUI cable to the card). Lots 'o
people make them, AT&T calls it an AUI adapter, UB calls it a TPAU, HP makes
one (I think they call it an AUI adapter too.)

If the card dosn't have a AUI port - this should work too -

A Company in L.A. makes a 10baseT TP to thinnet adapter, just hang it off
a hub port and thinnet cable out to the card.

I don't have the name of the company here, but they ran an ad in the
December issue of LAN mag.

brooks@osiris.cso.uiuc.edu (01/17/90)

You can purchase thin-to-thick converters for just a few dollars that
will do the trick.  This is just a simple little connector that has
a BNC plus on one side and an N type on the other for the thick cable.


I can't find a brand or part number at the moment, but if you're
interested, send me email and I'll track it down but I use them
quite a bit.