From: cornhead@netcom.com (Jeff Miller)
Newsgroups: misc.forsale.computers
Subject: Ethernet Transceivers, 15 pin-to-coax, for sale
Date: 12 Aug 92 22:04:16 GMT
Followup-To: poster
Organization: Netcom - Online Communication Services  (408 241-9760 guest)

I have some ethernet transcievers for sale. These are needed to attach machines
such as Suns (most models) which have 15 pin AUI ethernet connectors to 
network media such as Thinnet and Thicknet coax cable. Note active circuitry 
of some kind is always needed to connect AUI equipped machines, xcvrs are 
most commonly used.  

Each of the transceivers I am selling will require a little work to attach 
to any given run of coax. I might be willing to do some of it for you, 
as explained below. There is a good deal of paranoia about working 
with ethernet but I have yet to try anything that doesn't work. 

SQE is also called Heartbeat, it is best if you know if your computer 
requires it. I know Suns do not need it, but I have used xcvrs with SQE 
on several Suns with no apparent difficulties or loss of performance. 

TCL Boxes: 2*3*4 inches, 5 avail, $40 ea.

Vampire tap stub on one side. Solder to the stub or attach via alligator 
clips for quick-disconnect. Can be adapted directly to a BNC jack with 
appropriate (series of?) common adaptors but I never got a handle on which.
Some have SQE, some don't. I can't tell.

802.3 Transceivers:

802.3 transcievers seem like a good idea. Any given MAU accepts a range 
of standard, interchangeable heads for attachment to any given coax media. 
The problem is, the heads are expensive even though they are completely 
passive, and hard to find used. I do have some vampire tap heads 
designed for Thicknet cable but I think they suffer if they are used 
more than once and these are used. You're welcome to them but I recommend 
 you go to Radio Shack and buy a panel-mount BNC jack, solder wire-wrap wire 
or like that to it, stick the wires into the leaf spring contacts inside the 
MAU, mount the BNC jack in a piece of cardboard (don't use metal), 
add some tape and viola: a Thinnet transciever. All of the following 
are 802.3.

Interlan NT100's, 10*2*3 inches, SQE unknown: 5 avail, $40 ea.

Isolan 1116 : 4.5*2*3 inches, with SQE: 5 avail, $45 each

3COM 3C10X : 6*3*1.25 inches, SQE selectable: 5 avail., $50 ea

Cabletron ST-500 : 3.25*1.75*3 inches, SQE selectable, 10 avail., $60 ea.

The Cabletrons have five LEDS to indicate status. These are usefull 
for troubleshooting (especially cabling problems) but more importantly 
it's fun to watch them flicker as your packets get sucked in and out 
of your machine. 

Extras:

If interest is high (ie:more than 5 people) I might work up a batch of 
BNC widgets for the 802.3 xcvr. I'll use Plexiglas instead of 
cardboard and if you know whether or not you need SQE will seal it 
up with a little silicone glue. Shooting for $8 each. 

Same goes for drop cables: I usually use ribbon cable with IDC connectors, 
it's probably high in RFI but it works. The connectors are more expensive 
than they should be but I might be able to hit $8 for them too. 

Drop cables connect your workstation to your transciever.

I will analyze lower offers when time permits and if transceivers remain. 

I'll pay shipping if you pre-pay by check, I love that method. References 
available. Otherwise you pay shipping and COD.

Send mail to me as cornhead@netcom.com if you're interested. Thanks.