[sci.electronics] Cable converters that don't disturb channel mapping

mark@hermesa.uucp (Mark McWiggins) (06/23/91)

I subscribe to a couple of premium cable channels that require a descrambler.
The descrambler maps everything to channel 3.  If I had an "inline"
descrambler, it would generally be much handier for me; I could tape one
premium channel while watching another, etc.

Does anyone offer this?  Is there some technical reason why it's not feasible?

By the way: I'm not interested in ripping off the cable company, just in
more effective use of my equipment.  Thanks in advance for any insight.
-- 
Mark McWiggins
mark@hermesa.uucp 
...uw-beaver!amc-gw!hermesa!mark
Box 40357, Bellevue WA  98004 / +1 206 455 2786 (24 hrs.)

barmar@think.com (Barry Margolin) (06/24/91)

In article <1991Jun22.225534.4713@hermesa.uucp> mark@hermesa.uucp (Mark McWiggins) writes:
>I subscribe to a couple of premium cable channels that require a descrambler.
>The descrambler maps everything to channel 3.  If I had an "inline"
>descrambler, it would generally be much handier for me; I could tape one
>premium channel while watching another, etc.
>
>Does anyone offer this?  Is there some technical reason why it's not feasible?

It would be more expensive.  Most converters only have only one tuner and
descrambler circuit, so only one channel's signal can be descrambled at a
time.  To permit simultaneous descrambling of all premium channels you'd
need as many tuner/descrambler combinations as there are premium channels.

Also, many cable companies derive revenues from rental of additional
converters, when a customer has more than one TV they want to watch premium
channels on, so they might not want to make it so easy to connect multiple
TVs to the same converter.

-- 
Barry Margolin, Thinking Machines Corp.

barmar@think.com
{uunet,harvard}!think!barmar

brown@vidiot.UUCP (Vidiot) (06/24/91)

In article <1991Jun22.225534.4713@hermesa.uucp> mark@hermesa.uucp (Mark McWiggins) writes:
<I subscribe to a couple of premium cable channels that require a descrambler.
<The descrambler maps everything to channel 3.  If I had an "inline"
<descrambler, it would generally be much handier for me; I could tape one
<premium channel while watching another, etc.
<
<Does anyone offer this?  Is there some technical reason why it's not feasible?

Technically not feasible at this time.  Actually it is cost prohibitive.  It
can be done, but at great cost.  No cable viewer would want to pay for such
a box.
-- 
      harvard\     att!nicmad\          spool.cs.wisc.edu!astroatc!vidiot!brown
Vidiot  ucbvax!uwvax..........!astroatc!vidiot!brown
      rutgers/  decvax!nicmad/ INTERNET:vidiot!brown%astroatc@spool.cs.wisc.edu

flash@lopez.UUCP (Gary Bourgois) (06/25/91)

In <1976@vidiot.UUCP> brown@vidiot.UUCP (Vidiot) writes:

><The descrambler maps everything to channel 3.  If I had an "inline"
><descrambler, it would generally be much handier for me; I could tape one
><premium channel while watching another, etc.
><
><Does anyone offer this?  Is there some technical reason why it's not feasible?

>Technically not feasible at this time.  Actually it is cost prohibitive.  It
>can be done, but at great cost.  No cable viewer would want to pay for such
>a box.

Mr. Videot is semi-correct.  It depends on how many premium channels,
and how your system is set up, and how much you want to play.  What I
did years ago in a similar situation was to use ONE descrambler to feed
a separate cable to the rest of my home with an A/B switch so I could
watch HBO in any room on the second cable.  Then I got creative and
acquired a modulator that fed an unused channel and re inserted HBO
there.  This made it work on ONE main cable that fed my home, and I
could tape HBO like it was a regular station.

I got my stuff for free.  The modulator was an old tube type unit I got
from a friend who used to rebuild cable TV head ends.  I have seen these
units new for $202, which may or may not be cost prohibitive.  You will
also need a means of DEMODULATING the signal, which can be had for
around $70.  SO for under $300 per channel you can do it with new
components.  You can also do it for near free if you know someone in the
cable TV business, or know what to look for at a Hamfest.  You can even
use an old VCR to do this (One which has a working tuner, but the
mechanics are blown).  In this case you would set the VCR to either
channel 3 or 4, and would have to build up a filter network to remove
the existing channel 3 or 4 (hope it has nothing you want to watch) and
also filter the VCR's output to keep it narrower so it wont interfer
with ajacent channels.

The point is, where there is a will, there is a way.  I currently
distrubute THREE in house channels on my home cable system.  One has my
satellite dish, one has a vcr for watching tapes in any room, and one
has the status display of the BBS that I run (lopez).  My total out or
pocket expense for this system was about $40 (the UHF modulator, a
startron, which is no longer available, sadly) 

I would not let anyone telling me something can't be done stop me from
doing it.

-- 
=Marquette MI: It's Not the END of the world, but you can see it from here=
==  Gary Bourgois flash@lopez (rutgers!sharkey!lopez!flash)  GWN UPLink  ==
==  3.950  Nationwide Amateur Radio Nightly after 0200z=Learning Channel ==
=============== WB8EOH = The Eccentric Old Hippie = WB8EOH ================

greg@hoss.unl.edu (Life...) (06/29/91)

barmar@think.com (Barry Margolin) writes:
>mark@hermesa.uucp (Mark McWiggins) writes:

>>I subscribe to a couple of premium cable channels that require a descrambler.
>>The descrambler maps everything to channel 3.  If I had an "inline"
>>descrambler, it would generally be much handier for me; I could tape one
>>premium channel while watching another, etc.
>>
>>Does anyone offer this?  Is there some technical reason why it's not feasible?

I am told that the cable company in Omaha, NE has this.  Lincoln, NE says
they are working on it.  (They have also mentioned a 5 channel tuner, and
upgrading service for more than 36 channels, which are yet to be seen.)

>It would be more expensive.  Most converters only have only one tuner and
>descrambler circuit, so only one channel's signal can be descrambled at a
>time.  To permit simultaneous descrambling of all premium channels you'd
>need as many tuner/descrambler combinations as there are premium channels.

Ord, NE as far as I know has never had descrambler boxes in homes, yet
they have more than one premium channel now.  The population of the town
is less than 3000 people.  We've had TVs connected in 3 different places
in the house, 2 at a time, and no problems.

>Barry Margolin, Thinking Machines Corp.
>barmar@think.com
>{uunet,harvard}!think!barmar

Right now I am resorting to two AB switch boxes.  The first controls the
signal going to the VCR (box or cable), and the second controls the signal
going to the TV (VCR or cable).  That way I can record a scrambled channel
while watching something else.  I can even listen to them both!

--
///   ____   \\\ "The major problem--one of the major problems, for there are
| |/ /    \ \| |       several--one of the many major problems with governing
 \\_|\____/|_//            people is of whom you get to do it, or more to the
greg \_\\\/ hoss.unl.edu    point, who gets people to let them do it to them."