1 Apr
2009
1 Apr
'09
11:16 a.m.
Hello all,
Does anyone have any AUI cables they do not need? I could use about five
or six and the shorter, the better. The minimum is 2 meters, I believe.
Cables at 2m or 3m would be ideal. This would be a contribution to the
"worlds most complex network" that is growing in my basement.
Also a source for some thick Ethernet cable would be a big help.
Contact me off list if you can help.
Jim
1 Apr
1 Apr
11:32 a.m.
>>>> "Jim" == Jim Scheef
<scheefj at netscape.net> writes:
Jim> Also a source for some thick Ethernet cable would be a big help.
Plain old RG-8/U should serve if you can't find the real thing. The
specs aren't quite the same, but the most critical ones (impedance,
inner conductor and outer jacket sizes) match. Also, plain RG-8
doesn't have the 2.5 meter stripes, so you have to measure out
multiples of 2.5 meters for the transceiver placement.
(Alternatively, for small networks you can ignore the placement rule.
For large networks it matters.)
paul
6:17 p.m.
In article <18899.35064.421120.677345 at pkoning-laptop.equallogic.com>,
Paul Koning <Paul_Koning at Dell.com> writes:
inner conductor and outer jacket sizes) match. Also,
plain RG-8
doesn't have the 2.5 meter stripes, so you have to measure out
multiples of 2.5 meters for the transceiver placement.
What's the significance of the 2.5m interval?
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7:32 p.m.
Richard wrote:
In article <18899.35064.421120.677345 at
pkoning-laptop.equallogic.com>,
Paul Koning <Paul_Koning at Dell.com> writes:
It's some prime-number-fraction (17 IIRC but it's been a while) of the
wavelength of the data bits (and it's too late tonight to work it
out[1]) The idea is to ensure that the interference effects introduced
by the discontinuities of the taps are not additive.
[1] I've just got back to my room from the 25th anniversary dinner of
JANET, the Joint Academic NETwork which is sort of the UK equivalent of
Arpanet.
--
Pete Peter Turnbull
Network Manager
University of York
inner conductor and outer jacket sizes) match.
Also, plain RG-8
doesn't have the 2.5 meter stripes, so you have to measure out
multiples of 2.5 meters for the transceiver placement.
What's the significance of the 2.5m interval?
2 Apr
2 Apr
10:15 a.m.
>>>> "Pete" == Pete Turnbull
<pete at dunnington.plus.com> writes:
Pete> Richard wrote:
> What's the significance of the 2.5m interval?
Pete> It's some prime-number-fraction (17 IIRC but it's been a while)
Pete> of the wavelength of the data bits (and it's too late tonight
Pete> to work it out[1]) The idea is to ensure that the interference
Pete> effects introduced by the discontinuities of the taps are not
Pete> additive.
Essentially, yes. That is the purpose. It's not actually a round
number multiple, or round fraction multiple, of the wavelength. Using
the minimum velocity factor given in the 802.3 and DIX specs (0.77),
2.5 meters translates to 0.10823 wavelengths, or 1/9.24 wavelengths.
That makes sense, it's not a round number or 1/round number, so you
don't get constructive interference even if you have transceivers
separated by several marks.
Then again, it's all somewhat approximate because the spacing is fixed
while the velocity factor only has a minimum spec. But you don't get
in trouble (with a round number) until you have a VF of 0.83, which is
pretty high for small coax so the designers may have figured that
practical cable would be 0.77 or above, but below 0.83.
paul
1 Apr
1 Apr
11:43 a.m.
Does anyone have any AUI cables they do not need? I
could use about five
or six and the shorter, the better. The minimum is 2 meters, I
believe. Cables at 2m or 3m would be ideal. This would be a contribution
to the "worlds most complex network" that is growing in my basement.
If you can't scare up enough donations, these folks seem to have fairly
cheap ones:
http://www.monoprice.com/products/search.asp?keyword=aui&x=0&y=0
De
3:22 p.m.
Depends where you are. I have plenty, but postage to the USA would be more
than buying new ones.......
Jim.
----- Original Message -----
From: "Jim Scheef" <scheefj at netscape.net>
To: "General Discussion: On-Topic and Off-Topic Posts"
<cctalk at classiccmp.org>
Sent: Wednesday, April 01, 2009 4:16 PM
Subject: AUI cables needed
Hello all,
Does anyone have any AUI cables they do not need? I could use about five
or six and the shorter, the better. The minimum is 2 meters, I believe.
Cables at 2m or 3m would be ideal. This would be a contribution to the
"worlds most complex network" that is growing in my basement.
Also a source for some thick Ethernet cable would be a big help.
Contact me off list if you can help.
Jim
--------------------------------------------------------------------------------
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13:05:00
2 Apr
2 Apr
12:58 p.m.
Does anyone have any AUI cables they do not need? I
could use about
five or six and the shorter, the better. The minimum is 2 meters, I
believe.
I don't know the spec, but I once made a cable with two DA15s and about
a foot of 15-conductor ribbon cable and it worked fine. (At 10Mbit
speeds, a foot of wire gets lost in the impedance bump caused by the
connectors in the first place. Or at least that was the theory, and
the practice seemed to bear it out.)
There can't really be any true minimum; transceivers are regularly
plugged directly into machines, so zero-length "cables" work. :-)
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8:04 p.m.
Looking for some "frozen yellow garden hose?"
I have a spool of thicknet here. It's marked "DEC" and of course has a
paint mark every meter where you can tap it. There's an N-connector on one
end, the other end is cut.
The spool is marked "320 feet" but I don't see how there can be that much
on it. I believe there's two layers of cable left wound on the spool, 42
turns, 57" from one point on the spool to the same point on the next turn
(very approximately) yields, whoa, 399 feet? Hmmm. Well, maybe there is 320
feet on it.
I had thought to use it for amateur radio, since it's the right impedance,
but I dunnol how much loss I'd see at VHF frequencies. I use 50 and 144 MHz
radios, and 440 MHz UHF but I don't think this stuff is any good for UHF.
But my problems would be terminating it in anything but an N-connector, and
the fact that it would break down rapidly from UV exposure if I try to use
it outdoors.
Make offer. Pick up in Southeastern Wisconsin. Or call a motor freight
company for a quote for pickup and shipping from 53051.
73 de N9QQB
At 11:16 AM 4/1/2009 -0400, you wrote:
Hello all,
Does anyone have any AUI cables they do not need? I could use about five
or six and the shorter, the better. The minimum is 2 meters, I believe.
Cables at 2m or 3m would be ideal. This would be a contribution to the
"worlds most complex network" that is growing in my basement.
Also a source for some thick Ethernet cable would be a big help.
Contact me off list if you can help.
Jim
-----
231. [Internet] .sigs are the bumper stickers of the information superhighway.
--... ...-- -.. . -. ----. --.- --.- -...
tpeters at nospam.mixcom.com (remove "nospam") N9QQB (amateur radio)
"HEY YOU" (loud shouting) WEB: http://www.mixweb.com/tpeters
43? 7' 17.2" N by 88? 6' 28.9" W, Elevation 815', Grid Square
EN53wc
WAN/LAN/Telcom Analyst, Tech Writer, MCP, CCNA, Registered Linux User 385531
8:20 p.m.
On Thu, Apr 2, 2009 at 8:04 PM, Tom Peters <tpeters at mixcom.com> wrote:
Looking for some "frozen yellow garden
hose?"
I have been looking casually for years. I even have taps for it.
I have a spool of thicknet here. It's marked
"DEC" and of course has a paint
mark every meter where you can tap it. There's an N-connector on one end,
the other end is cut.
Beautiful.
The spool is marked "320 feet" but I
don't see how there can be that much on
it. I believe there's two layers of cable left wound on the spool, 42 turns,
57" from one point on the spool to the same point on the next turn (very
approximately) yields, whoa, 399 feet? Hmmm. Well, maybe there is 320 feet
on it.
That's a lot of Etherhose.
Make offer. Pick up in Southeastern Wisconsin. Or call
a motor freight
company for a quote for pickup and shipping from 53051.
Hmm... I'm supposed to be in Madison sometime this month. How much
does it weigh? (wondering about trying to check it on the flight).
-ethan
8:24 p.m.
On Thu, Apr 02, 2009 at 07:04:55PM -0500, Tom Peters wrote:
Looking for some "frozen yellow garden
hose?"
I have a spool of thicknet here. It's marked "DEC" and of course has a
...
I had thought to use it for amateur radio, since
it's the right impedance,
Yellow coax degrades very quickly in the sunlight, the black of coax
is from carbon black used to protect the cable. It would work, but
degrade very quickly.
- 73 Diane VA3DB
--
- db at FreeBSD.org db at db.net http://www.db.net/~db
25 Apr
25 Apr
6:21 p.m.
Tom and all,
My apologies for ignoring the list for a time.
That spool is a bit more than I need (even ignoring the distance
involved), but your message does make me think that obtaining some
thicknet is going to be a challenge. It is not exactly conducive to
shipment by parcel post. What is the minimum diameter that thicknet
could be looped and still be straightened back out? I suspect that, like
electrical conduit, it is "bend twice only" and pulling it off the spool
counts as the first bend.
At some point I may try to have some shipped directly to InfoAge for the
MARCH museum but I need to make it work at home first.
Jim
Tom Peters wrote:
Looking for some "frozen yellow garden
hose?"
I have a spool of thicknet here. It's marked "DEC" and of course has a
paint mark every meter where you can tap it. There's an N-connector on
one end, the other end is cut.
The spool is marked "320 feet" but I don't see how there can be that
much on it. I believe there's two layers of cable left wound on the
spool, 42 turns, 57" from one point on the spool to the same point on
the next turn (very approximately) yields, whoa, 399 feet? Hmmm. Well,
maybe there is 320 feet on it.
I had thought to use it for amateur radio, since it's the right
impedance, but I dunnol how much loss I'd see at VHF frequencies. I use
50 and 144 MHz radios, and 440 MHz UHF but I don't think this stuff is
any good for UHF. But my problems would be terminating it in anything
but an N-connector, and the fact that it would break down rapidly from
UV exposure if I try to use it outdoors.
Make offer. Pick up in Southeastern Wisconsin. Or call a motor freight
company for a quote for pickup and shipping from 53051.
73 de N9QQB
5568
days inactive
5592
days old
11 comments
10 participants
participants (10)
-
db＠db.net -
drb＠msu.edu -
ethan.dicks＠gmail.com -
jim＠g1jbg.co.uk -
legalize＠xmission.com -
mouse＠Rodents-Montreal.ORG -
Paul_Koning＠Dell.com -
pete＠dunnington.plus.com -
scheefj＠netscape.net -
tpeters＠mixcom.com