Re: [school-discuss] Cat-5 question

[Cameron Miller <cdmiller@adams.edu>]

I concur with Chris and Matt.  Use solid core for long runs and stranded 
for patch cables.  A decent tester and good crimper can save lots of time.

- cameron

Matt Drew wrote:
> Also make sure you have a quality crimper.  A low-quality crimper will 
> often wear out over time, and begin to crimp bad connections even when 
> it looks okay to the eye.
> 
> Matt
> 
> Chris Puttick wrote:
> 
>> Solid core is normally used for longer runs (lower resistance/metre) 
>> than multicore, where multicore is normally used for fly and patch 
>> leads (outside of the building structure) because of the greater 
>> resistance to flex (bend a solid core enough times one or more of the 
>> cores breaks).
>>
>> The other issue is this: IDC connectors (normally found on the back of 
>> the RJ45 socket are designed to use solid core, and the RJ45 plugs are 
>> (with specific exceptions) designed to be used with multicore. Trying 
>> to terminate the wrong type of cable into the wrong type of 
>> socket/plug will often result in poor or missing termination, even 
>> though visually it looks ok.
>>
>> A cheap cable tester can save much heartache and head scratching, a 
>> mid priced one (say a Fluke  620) even more. Now if you're very rich, 
>> there's nothing like a DSP2000 to sort out all your etwork cabling 
>> problems... (or if you know a school that has Cisco Academy status, 
>> borrow theirs!)
>>
>> Cheers
>>
>> Chris
>>
>> -----Original Message-----
>> From: Jim Aird
>> To: schoolforge-discuss@schoolforge.net
>> Sent: 8/14/02 1:09 AM
>> Subject: [school-discuss] Cat-5 question
>>
>> I just got a new box (1000ft) of cat-5 cable and made five new runs
>> through my office but couldn't get the links to come up.  After several
>> hours of troubleshooting, re-crimping cables, moving hardware etc. I
>> discovered that the new cable (four twisted pairs) is conducting on many
>>
>> tiny fibers of copper while the rest of our building, running fine, has
>> a solid piece of copper within each of the 8 individual strands.
>> Otherwise there is no difference.
>>
>> Am I going nuts or is there something to the solid piece vs. the many
>> tiny strands difference?
>>
>> Any help within the next 1-24 hours would be a huge help, so I can be
>> ready to drop in our new set of servers and firewalls and offer internet
>>
>> filtering (squid) and related services to the students by the first day
>> of school.
>>
>> Jim Aird
>> HomeTech Charter School
>>
> 
> 
> 

-- 
- cameron miller
- UNIX Systems Administrator
- Outhouse Attendant
- cdmiller@adams.edu