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Old November 23rd 05, 08:42 PM posted to rec.radio.amateur.antenna
Michael Coslo
 
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Default Radio Shack and my education



Dave wrote:

"Michael Coslo" wrote in message
...

Slightly OT, but kinda fun anyhow.....

I'd been trying to locate a reasonably priced USB cable over the weekend
It seems that you often pay as much for the cable as you fo for the device
you are connecting to the computer.

Has stereo voodoo physics entered the computer realm?

Anyhow, I ended up in a Radio Shack store, found the cheapest cable I
could, (20 bucks) and made the mistake of mentioning something to the
salesman about the funny claims on the packages. Big mistake, I had
blasphemed his religion. In the next couple minutes I learned that:

Turns out that different frequencies travel at different speeds down the
cable. Good cables have special formulations of wire that compensate for
this.

Everybody knows that!



you didn't know that? its called frequency dispersion. fortunately it is a
relatively small effect and in normal bandwidths hams use it can be ignored.
for very high bandwidth signals like high speed digital stuff it can badly
distort the waveforms and can be the limiting factor in determining maximum
cable lengths without repeaters.




Oh yes, I've heard of dispersion. But that isn't what the guy was
talking about in our context. He was talking about gross effects.

- Mike KB3EIA -