PAT wrote:
> [TELECOM Digest Editor's Note: Something I do not understand
> about our Cable One system is this: (Basic) channels are
> numbered 2 though 62 with no channel 0 or 1 and no channel 4,
> sixty channels total.
There's no 0 or 1 because Cable One's basic service uses the STD
("standard") channel-numbering plan, and this plan doesn't include 0 or
1. See the "Standard Carrier Frequency" column at
<http://www.annsgarden.com/telecom/CATV.html>.
Cable One probably doesn't use cable channel 4 because of possible
direct pickup from K04EJ, a 310-watt station in Coffeyville owned by
Coffeyville Community College. A strong off-air signal could get
directly into the internal wiring of a poorly-shielded television set
that had been connected directly to the cable (without a converter),
and cause interference to any signal carried on cable channel 4.
This would be the case even if Cable One carried K04EJ *on* cable
channel 4. Even though signals move pretty fast through a cable
network, there's still a delay of a few microseconds. If an off-air
signal and a cable signal both arrive at the TV set, one signal will
appear as a ghost in the other.
At 310 watts, K04EJ isn't a very strong station, but Independence is
only about 13 miles away, so you could still be receiving a fairly
strong signal.
> here is a channel 3 on our cable which happens to be Fox out
> of Tulsa. Our converter boxes come with arrangements to use a
> switch on the back to set the converter to do its output on
> channel 3 or 4, depending. My thinking was since there is a
> channel 3, put the converter box output to channel 4 which is
> otherwise vacant. But no, Cable One says use the '3' side of
> the converter switch *even though they also put stuff on
> channel 3.
Assuming the converter is properly designed, there's no reason the
output channel can't be the same as one of the input channels. Cable
One doesn't use channel 4 as the converter-output channel for the same
reason they don't use it as a cable channel: potential interference
from K04EJ.
> In fact, if you put the converter box on 4 and also
> set the television set to '4', we only get a snowy, grainy
> picture.
Disconnect the converter, hook the TV set up to an antenna, and see
what you get. My guess: you'll see K04EJ.
> Their full spectrum of 'channels' runs from channel 2 through
> channel 938 if you have their full package (2 through 62,
> basic), (101 through 1xx, then 200 through 2xx, etc. up
> through 901 through 938 which are the music channels, in total
> about 400 channels total, with lots of vacancies in the
> middle.) But they do not use zero, or one, or four for some
> reason.
See explanation above.
> Also, when manually tuning a cable channel where nothing is
> located, the cable does not allow the remote to be stopped on a
> vacant spot (even if requested) but automatically goes to the
> next highest actual channel, with one exception, channel 70,
> just above the basic group of channels. The coverter will stop
> on 70 if you request it to, and you get a continuous black
> screen, almost like a television station is there but with
> carrier but no other output. Ignoring the cable converter and
> manually tuning the television to channel 70 I usually just get
> snow and hiss, but sometimes I get a 'ghost image' of some
> cable channel instead. Can anyone explain any of this? PAT]
See "The Mysterious Cable Channel 70" at <http://tinyurl.com/43tt9>.
Neal McLain
[TELECOM Digest Editor's Note: I read your tinyurl page and it was
quite interesting. I also tried your suggestion about an antenna on
the television and over the air signals from Channel 4. I did *not*
get anything different than what I got before (some hiss and snow with
a very faint image.) However, if what you suggest is true about inter-
ference from Coffeyville CC, then why isn't that also true of the guy
who does the low power repeater of Trinity Broacasting on (I think)
channel 22 or 23 here in Indy? Cable One does not block out that
channel on account of him; in fact I think Trinity is on our cable 22.
I seem to remember channel 4 from *years* ago when as a young kid I
lived and visited in Coffeyville. It seems to me it was a 24 hour
per day transmission of some weather station. The cameras always
looking at the weather dials, and background music. That would have
been 1954-55. PAT]
Neal McLain (nmclain@annsgarden.com)