Re: best way to get a //c monitor cable?

[mjmahon@aol.com (Michael J. Mahon)]

Ralph Glatt wrote:

>mjmahon@aol.com (Michael J. Mahon) wrote in message
>news:<20040828123205.23168.00004515@mb-m07.aol.com>...
>> Ed Eastman wrote:
>> 
>> >And yes, a shielded cable works far better than an unsheilded 
>> >one.  Go to your local electronic place and pick up an shielded RCA 
>> >Video cable for best results.
>> 
>> What am I missing here?
>> 
>> Virtually all RCA cables are coaxial (shielded) cables.  The ones
>> intended for video use usually have a lower dielectric constant
>> insulation between the center wire and the shield, but otherwise
>> there is little difference.  There is no place to connect a shield
>> except to the coax braid (shield) anyway.
>> 
>> A shorter cable will work better than an unnecessarily long
>> one, just because the extra capacitance lowers the bandwidth
>> of the video signal.
>
>Well, here's my story. 
>
>I bought a used //c at a garage sale, and it had this skinny little
>cable that looked like it came with the computer originally. When I
>hooked it up, the screen was all swimmy and wavy. Went down to Radio
>Shack, specifically bought a shielded cable, and when I tried it, the
>waviness went away. I'm guessing that the thinner cables are more
>susceptible to inteference than a thicker, shielded cable.

And I'm betting that the cable or connectors were defective.
Even a low-quality audio RCA cable should work perfectly,
especially if it is just 3ft or so.

The symptom you describe is most likely caused by a connector
making imperfect contact.

RF noise getting into a video monitor (not a TV) is very unlikely
to be a problem.  The noise-supressing ferrite beads used on
some cables are there to prevent the cable radiating interference
to a nearby TV set, not to improve the signal delivered to the
monitor it's connected to.

Apple II RCA connectors are notorious for breaking or becoming
intermittent, at least on the "full size" Apple IIs.  The construction
of the connector makes it prone to break the center connection
if you have a habit of twisting the RCA connector as you insert
it, which is usually the best way to ensure a good connection.

Multiple straight-in insertions and removals are the best way to
"clean" an Apple II video connector, and even then, the damage
may already have been done and the connector will need to be
resoldered to restore good connections.

-michael

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