DComTalk.com

I'm trying to set up a 10base5 segment at home, can I use radio amateur
type rg-8 or do I have to have the yellow rg8 designed for 10base5? I
have tranceivers and a piercing tap, and assume I can terminate with a
resister between ground and center. I think I saw they were only
terminated at ONE end, but maybe it would be better to terminate with
150 ohms at both ends? After all, 10base2 was supposed to be
terminated at both ends, wasn't it (I always did)?

Also, does anyody have operating 10broad36 or any of the 1 mb/sec
ethernet-like protocols?

In article <1110193199.525710.184110@l41g2000cwc.googlegroups.com>,
sqrfolkdnc <carey.schug@gmail.com> wrote:

I'm trying to set up a 10base5 segment at home, can I use radio amateur
type rg-8 or do I have to have the yellow rg8 designed for 10base5? I
have tranceivers and a piercing tap, and assume I can terminate with a
resister between ground and center. I think I saw they were only
terminated at ONE end, but maybe it would be better to terminate with
150 ohms at both ends? After all, 10base2 was supposed to be
terminated at both ends, wasn't it (I always did)?

Also, does anyody have operating 10broad36 or any of the 1 mb/sec
ethernet-like protocols?

The orange cable was terminated at both ends with 50 ohm (nominal)
N connector terminators.

ISTR that a tap in 10base5 was capacitive. It was just a little
antenna poked thru the coax shield. Google for "ethernet blue book
dec intel xerox". You might interesting info.

Looking for info I found this blast from the past, last updated in 1994.

http://suresh_kr.tripod.com/ethernet.txt

Who knows what will work with a small hobbyist network but when it was
curent nobody ever used anything but the orange cable, for many
reasons. For one, the tap clamps wouldn't fit right on coax unless
the O.D. was correct. Nobody I know tried anything but orange cable.

Putting the taps in was a big deal at first. There was a tool kit that
had a battery electric drill, a jig, and the right drill bits. Later,
3rd-party taps came along that were self-tapping, they came with a
hex wrench.
--

a d y k e s @ p a n i x . c o m

Don't blame me. I voted for Gore.

sqrfolkdnc wrote:

I'm trying to set up a 10base5 segment at home, can I use radio amateur
type rg-8 or do I have to have the yellow rg8 designed for 10base5? I
have tranceivers and a piercing tap, and assume I can terminate with a
resister between ground and center. I think I saw they were only
terminated at ONE end, but maybe it would be better to terminate with
150 ohms at both ends?

50 Ohms, not 150. And you terminate at both ends. You _ground_ at only one
point.

After all, 10base2 was supposed to be
terminated at both ends, wasn't it (I always did)?

Also, does anyody have operating 10broad36 or any of the 1 mb/sec
ethernet-like protocols?

Ebay is your friend and good hunting.

--
--John
to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)

sqrfolkdnc wrote:

I'm trying to set up a 10base5 segment at home, can I use radio amateur
type rg-8 or do I have to have the yellow rg8 designed for 10base5? I
have tranceivers and a piercing tap, and assume I can terminate with a
resister between ground and center. I think I saw they were only
terminated at ONE end, but maybe it would be better to terminate with
150 ohms at both ends? After all, 10base2 was supposed to be
terminated at both ends, wasn't it (I always did)?

Also, does anyody have operating 10broad36 or any of the 1 mb/sec
ethernet-like protocols?

Why one earth would you want to take such a huge step backwards? While you
could use RG-8, I believe the ethernet cable was made with specific tap
points, where it was easier to connect the taps. Also, you need 50 ohm
terminators at each end. Do you also have NICs that can support the
transceivers?

In article <mMidnZ2FCM-r_LHfRVn-3Q@rogers.com>,
James Knott <james.knott@rogers.com> wrote:

sqrfolkdnc wrote:

I'm trying to set up a 10base5 segment at home, can I use radio amateur
type rg-8 or do I have to have the yellow rg8 designed for 10base5? I
have tranceivers and a piercing tap, and assume I can terminate with a
resister between ground and center. I think I saw they were only
terminated at ONE end, but maybe it would be better to terminate with
150 ohms at both ends? After all, 10base2 was supposed to be
terminated at both ends, wasn't it (I always did)?

Also, does anyody have operating 10broad36 or any of the 1 mb/sec
ethernet-like protocols?

Why one earth would you want to take such a huge step backwards? While you
could use RG-8, I believe the ethernet cable was made with specific tap
points, where it was easier to connect the taps. Also, you need 50 ohm
terminators at each end. Do you also have NICs that can support the
transceivers?

It sounds like a hobbyist network. That's cool. Redirecting the
thread to alt.folklore.computers might get more info. A query there
might turn up orange cable and related bits of kit.

The stripes were for mandatory tap seperation.

There are lots of little adapters around to convert the AUI connector
on the tap to TW or UTP.

Google for a copy of the DEC/Xerox/Intel "Blue Book" spec for the
original ethernet. It's one of the clearer bits of technical writing
you'll ever read.
--

a d y k e s @ p a n i x . c o m

Don't blame me. I voted for Gore.

In article <d0hokc0288d@news4.newsguy.com>,
J. Clarke <jclarke.usenet@snet.net.invalid> wrote:

sqrfolkdnc wrote:

I'm trying to set up a 10base5 segment at home, can I use radio amateur
type rg-8 or do I have to have the yellow rg8 designed for 10base5? I
have tranceivers and a piercing tap, and assume I can terminate with a
resister between ground and center. I think I saw they were only
terminated at ONE end, but maybe it would be better to terminate with
150 ohms at both ends?

50 Ohms, not 150. And you terminate at both ends. You _ground_ at only one
point.

After all, 10base2 was supposed to be
terminated at both ends, wasn't it (I always did)?

Also, does anyody have operating 10broad36 or any of the 1 mb/sec
ethernet-like protocols?

Ebay is your friend and good hunting.

You've sure got a laundry list of standards there. Do you have any
idea how they fit in the marketpalce in their day ? I don't know what
"1 mb/sec/ ethernet-like" means. Mike Padlipsky's _The Elements of
Networking Style_ has an interesting chapter on how people thought
that IP (which was new and designed for point-to-point circuits)
couldn't work on Ethernet, a broadcast meduim.

There was _very_ little of the pre-Blue Book equipment made. It was
used only at Xerox and a few universities and since the original specs
allowed only a handfull of computers on a LAN there was not the tons
of desktop infrastructure to be found in dumpsters. As soon as the
10mb stuff hit the market (1981 ?) people with older stuff upgraded.
That was a long time ago.

At this point the discussion is firmly th the alt.folklore.computers
are and should be picked up there.


--

a d y k e s @ p a n i x . c o m

Don't blame me. I voted for Gore.

Al Dykes wrote:

In article <d0hokc0288d@news4.newsguy.com>,
J. Clarke <jclarke.usenet@snet.net.invalid> wrote:
sqrfolkdnc wrote:

I'm trying to set up a 10base5 segment at home, can I use radio amateur
type rg-8 or do I have to have the yellow rg8 designed for 10base5? I
have tranceivers and a piercing tap, and assume I can terminate with a
resister between ground and center. I think I saw they were only
terminated at ONE end, but maybe it would be better to terminate with
150 ohms at both ends?

50 Ohms, not 150. And you terminate at both ends. You _ground_ at only
one point.

After all, 10base2 was supposed to be
terminated at both ends, wasn't it (I always did)?

Also, does anyody have operating 10broad36 or any of the 1 mb/sec
ethernet-like protocols?

Ebay is your friend and good hunting.


You've sure got a laundry list of standards there. Do you have any
idea how they fit in the marketpalce in their day ? I don't know what
"1 mb/sec/ ethernet-like" means.

He's probably talking about Starlan and its kin. Thinking about it, I _may_
actually have some 1 Mb/sec Starlan hardware in the attic. If so it will
be ISA NICs--I'm pretty sure I don't have a hub.

Mike Padlipsky's _The Elements of
Networking Style_ has an interesting chapter on how people thought
that IP (which was new and designed for point-to-point circuits)
couldn't work on Ethernet, a broadcast meduim.

There was _very_ little of the pre-Blue Book equipment made. It was
used only at Xerox and a few universities and since the original specs
allowed only a handfull of computers on a LAN there was not the tons
of desktop infrastructure to be found in dumpsters. As soon as the
10mb stuff hit the market (1981 ?) people with older stuff upgraded.
That was a long time ago.

At this point the discussion is firmly th the alt.folklore.computers
are and should be picked up there.

--
--John
to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)

In article <d0hlih$86n$1@panix5.panix.com>, adykes@panix.com (Al Dykes)
wrote:

The orange cable was terminated at both ends with 50 ohm (nominal)
N connector terminators.

The orange cable was used for plenum applications; the more common cable
was bright yellow. (In fact, it was "1968 Corvette Yellow," to be
specific.) I have some of the original prototype batch in my garage.

ISTR that a tap in 10base5 was capacitive. It was just a little
antenna poked thru the coax shield. Google for "ethernet blue book
dec intel xerox". You might interesting info.

The tap was did not use capacitive coupling. It required that the
transceiver input have DC connectivity with both the center conductor
and the shield. (Remember, carrier-sense and collision-detect were based
on DC voltage thresholds; a capacitive coupler would not work for this
purpose.)


--
Rich Seifert Networks and Communications Consulting
21885 Bear Creek Way
(408) 395-5700 Los Gatos, CA 95033
(408) 228-0803 FAX

Send replies to: usenet at richseifert dot com

In article <usenet-761616.18052507032005@news.isp.giganews.com>,
Rich Seifert <usenet@richseifert.com.invalid> wrote:

In article <d0hlih$86n$1@panix5.panix.com>, adykes@panix.com (Al Dykes)
wrote:


The orange cable was terminated at both ends with 50 ohm (nominal)
N connector terminators.


The orange cable was used for plenum applications; the more common cable
was bright yellow. (In fact, it was "1968 Corvette Yellow," to be
specific.) I have some of the original prototype batch in my garage.

ISTR that a tap in 10base5 was capacitive. It was just a little
antenna poked thru the coax shield. Google for "ethernet blue book
dec intel xerox". You might interesting info.


The tap was did not use capacitive coupling. It required that the
transceiver input have DC connectivity with both the center conductor
and the shield. (Remember, carrier-sense and collision-detect were based
on DC voltage thresholds; a capacitive coupler would not work for this
purpose.)


--
Rich Seifert Networks and Communications Consulting
21885 Bear Creek Way
(408) 395-5700 Los Gatos, CA 95033
(408) 228-0803 FAX

Send replies to: usenet at richseifert dot com

I stand corrected, thanks, but having done just a few taps myself
don't see how that little pin could make a reliable connection, but It
worked.

--

a d y k e s @ p a n i x . c o m

Don't blame me. I voted for Gore.

Thanks to all who replied, I will try alt.folklore.computers. This was
my first foray into groups since a brief encounter with Sun groups
several years ago, and I came across the cisco group looking for
something else.

I have ONE N-I-B self tapping vampire tap and tranceiver. I have three
tranceivers (two dual and one quad) that clearly were inteded to be
spliced into RG-8 cable with coax connectors, although I have been
unable to find any information on the web about these. I have 14 long
and 8 short AUI cables and ISA cards/hubs/switches/routers with AUI
ports to connect them to. Besides 10base2, I also have a 10baseF hub
(optical fiber at 10 mb/sec) running in my lab/museum.

I assume the VERY FIRST thick was traditional black RG-8, the yellow
and orange came later, else why would they have used the rg-8 spec?
Yes, I knew the yellow cable was marked for tap points, I thought just
to enforce the separation, which I figure should not matter if I am not
trying to get published maximum distance. Yes, I got confused
vis-a-vis grounding at one point vs terminating at one end.

The 1MB/s protocals were starlan1 and 1base5, both running on
unshielded phone cable. It seems the 1 mb/s media were intended to be
a local interface from desktops, implying the hubs would also have 10
mb for connedtion to the backbone, so with two hubs and a crossover, I
could run it even though no current os would support any pc isa cards.
10broad36 was sharing coax with other signals (TV?) and supposed to go
3600 meters, hence the name, but some web documents said it only went
1800 meters.

If anybody can help with equpment, I would appreciate it. I'd like to
get a used vampire tap so I can keep the new one "new". I should be
able to get started with just the RG-8 (assuming I can make my own
terminators), and if I can't find yellow/orange, I'll try some local
radio amateurs I know to get a little from them (On Ebay I can buy 50
or 250 feet, and just the postage would exceed my budget).

sqrfolkdnc wrote:

I'm trying to set up a 10base5 segment at home, can I use radio amateur
type rg-8 or do I have to have the yellow rg8 designed for 10base5? I
have tranceivers and a piercing tap, and assume I can terminate with a
resister between ground and center. I think I saw they were only
terminated at ONE end, but maybe it would be better to terminate with
150 ohms at both ends? After all, 10base2 was supposed to be
terminated at both ends, wasn't it (I always did)?

Also, does anyody have operating 10broad36 or any of the 1 mb/sec
ethernet-like protocols?

Note that 10base2 is electrically the same as 10base5, you can
connect them together with BNC to N adapters. It is also easier
to find BNC 50 ohm terminators, as they are commonly used in other
than ethernet applications. My favorite are feed-through terminators
to avoid the tee on the last connection.

RG8 or RG213 will work fine. (The maximum length will be less,
but I don't expect that to cause you problems.) You can solder a 50
ohm resistor at each end if you want to. N connectors are expensive,
but you may be able to find them in surplus stores.

-- glen

In article <18CdnQVD--5O6bDfRVn-tg@comcast.com>,
glen herrmannsfeldt <gah@ugcs.caltech.edu> wrote:

sqrfolkdnc wrote:

I'm trying to set up a 10base5 segment at home, can I use radio amateur
type rg-8 or do I have to have the yellow rg8 designed for 10base5? I
have tranceivers and a piercing tap, and assume I can terminate with a
resister between ground and center. I think I saw they were only
terminated at ONE end, but maybe it would be better to terminate with
150 ohms at both ends? After all, 10base2 was supposed to be
terminated at both ends, wasn't it (I always did)?

Also, does anyody have operating 10broad36 or any of the 1 mb/sec
ethernet-like protocols?


Note that 10base2 is electrically the same as 10base5, you can
connect them together with BNC to N adapters. It is also easier
to find BNC 50 ohm terminators, as they are commonly used in other
than ethernet applications. My favorite are feed-through terminators
to avoid the tee on the last connection.

RG8 or RG213 will work fine. (The maximum length will be less,
but I don't expect that to cause you problems.) You can solder a 50
ohm resistor at each end if you want to. N connectors are expensive,
but you may be able to find them in surplus stores.

-- glen

There's lots of N hardware out there, and N-BNC adapters. Ask the
hams and check Fair Radio Sales.

http://www.fairradio.com/
--

a d y k e s @ p a n i x . c o m

Don't blame me. I voted for Gore.

In article <d0j1rh$3g7$1@panix5.panix.com>, adykes@panix.com (Al Dykes)
wrote:

I stand corrected, thanks, but having done just a few taps myself
don't see how that little pin could make a reliable connection, but It
worked.

Trust me, it took a *LOT* of mechanical and materials engineering to get
that system to work reliably. Back in 1980-82, I was working on an
almost daily basis with the folks at AMP in Harrisburg, PA who did the
original 10 Mb/s vampire tap. The difficulty is in having the tap pin
find its way through a viscous foam dielectric to achieve a solid berth
in the center conductor of the cable. The project engineer described it
as, "trying to nail Jello to a tree." His analogy was quite good.


--
Rich Seifert Networks and Communications Consulting
21885 Bear Creek Way
(408) 395-5700 Los Gatos, CA 95033
(408) 228-0803 FAX

Send replies to: usenet at richseifert dot com

In article <1110256475.061246.229280@l41g2000cwc.googlegroups.com>,
"sqrfolkdnc" <carey.schug@gmail.com> wrote:

I assume the VERY FIRST thick was traditional black RG-8, the yellow
and orange came later, else why would they have used the rg-8 spec?

The very first 10 Mb/s coax medium was in fact the custom-designed
yellow (and later, orange) cable; it was never RG-8, or any standard
cable. The electrical and mechanical requirements of the system
precluded off-the-shelf designs. (I personally designed the original
yellow/orange cables; they were manufactured for me by Belden (and
later, many others).

Yes, I knew the yellow cable was marked for tap points, I thought just
to enforce the separation, which I figure should not matter if I am not
trying to get published maximum distance.

The separation and the maximum distance are unrelated phenomenon. The
forced spacing was to prevent lumped capacitive loads on the system,
which could cause unacceptable signal reflections. The maximum cable
length is a function of the resistance of the center conductor, which
affects the carrier-sense and collision-detect thresholds.

If you have few taps (i.e., nowhere near the maximum of 100), the
spacing is not that critical.

10broad36 was sharing coax with other signals (TV?) and supposed to go
3600 meters, hence the name, but some web documents said it only went
1800 meters.

It all depends on how you measure it. Remember, 10BROAD36, like most
CATV-style systems, uses a head-end device at the "source" of the cable.
Thus, the maximum range is 1800 m (radius from the headend), or 3600 m
(diameter, or maximum distance between the farthest pair of end
stations); it's the same thing.

If anybody can help with equpment, I would appreciate it. I'd like to
get a used vampire tap so I can keep the new one "new". I should be
able to get started with just the RG-8 (assuming I can make my own
terminators), and if I can't find yellow/orange, I'll try some local
radio amateurs I know to get a little from them (On Ebay I can buy 50
or 250 feet, and just the postage would exceed my budget).

You may have problems trying to use RG-8 or any standard cable with a
vampire tap. The dimensions/geometry are simply wrong. Also, the tap is
designed to work only with a solid center conductor (not stranded) and a
foam dielectric. The standard solid polyethylene dielectric of RG-8 is
much too dense for the tap probe, and the higher dielectric constant
reduces the diameter of the cable, i.e., the tap probe will be too long.

I have a large spool of an early prototype Ethernet cable (from back in
the 1980 timeframe); it is dimensionally correct, but is black instead
of yellow, and has only a single braid/single foil shield (rather than
the double braid/double foil of the real stuff). In fact, it was tests
on this cable that brought me to add the additional shields. Unless you
are local in northern California, the shipping cost would exceed its
value to you.


--
Rich Seifert Networks and Communications Consulting
21885 Bear Creek Way
(408) 395-5700 Los Gatos, CA 95033
(408) 228-0803 FAX

Send replies to: usenet at richseifert dot com

Rich Seifert <usenet@richseifert.com.invalid> wrote:

Back in 1980-82, I was working on an almost daily basis with
the folks at AMP in Harrisburg, PA who did the original 10
Mb/s vampire tap. The difficulty is in having the tap pin
find its way through a viscous foam dielectric to achieve
a solid berth in the center conductor of the cable.

I'd've thought that a sprung system would be necessary. Forked
vampire tip to maintain contact, maybe with some spring in the
fork-tip (ala RJ solid IDC) or a slight curve in the vampire.

The project engineer described it as, "trying to nail Jello to
a tree." His analogy was quite good.

Jell-O can be very easily nailed to a tree. Put it in a can.
In this case, a long (6"?) circumferential compression clamp
around the yellow garden hose.

-- Robert