dcm@pyrite.nj.pyramid.com (David C. Miller) (02/27/91)
I recently added one of the pay channels to my cable service and
hit the following snag:
I can set my VCR to use its own tuner and can program it to record
programs from any of the unscrambled channels.
OR
I can set it to use the tuner supplied by the cable service and can
record only the one channel that it is tuned to.
Since this is an 8 event VCR, I find it frustrating to have to
switch between the internal and external tuner. If I go away
for a weekend, I have to choose to record only the unscrambled
channels or only the scrambled channel.
What I'm looking for is a way of adding a circuit that will
effectively unscramble the pay channel in place. The cable
company's converter unscrambles channel 28 and emits the clear
signal on channel 3. I want something to take this signal and
put it back on channel 28 and merge it back with the other cable
channels. The idea being that all but channel 28 comes straight
off the cable while channel 28 come in via the descrambler.
Cable Tuner +----- Channel 3 out
Descrambler |
Incoming cable with +-----+ v
scrambled signal on +------| |----+
channel 28 / +-----+ \+----+
--------------------+ | |------------+
^\ /+----+
cable splitter -----+ +-----------------+ ^
|
|
Device that blanks out channel 28 on --+
straight through line, then map channel 3
from the tuner to channel 28.
I figure that there must be at least 1 video hacker on the
net who's done this. Is there some insurmountable problem
that I'm not seeing?
David
dcm@pyrite.nj.pyramid.comwhit@milton.u.washington.edu (John Whitmore) (02/28/91)
In article <471@pyrite.nj.pyramid.com> dcm@pyrite.nj.pyramid.com (David C. Miller) writes: >Since this is an 8 event VCR, I find it frustrating to have to >switch between the internal and external tuner. If I go away >for a weekend, I have to choose to record only the unscrambled >channels or only the scrambled channel. > >What I'm looking for is a way of adding a circuit that will >effectively unscramble the pay channel in place. > > Cable Tuner +----- Channel 3 out > Descrambler | >Incoming cable with +-----+ v >scrambled signal on +------| |----+ >channel 28 / +-----+ \+----+ >--------------------+ | |------------+ > ^\ /+----+ >cable splitter -----+ +-----------------+ ^ > | > | >Device that blanks out channel 28 on --+ >straight through line, then map channel 3 >from the tuner to channel 28. You can do this with a UHF block converter; put the converter after the descrambler, and it will turn the 'CH 3' output into a UHF channel, which can go into your VCR's UHF input (or to a UHF/VHF combiner/splitter). It may in fact be more convenient to feed the descrambled signal straight, and mix everything else in the cable signal to UHF (so that you can set your VCR tuner to 'normal' instead of 'cable' tuning). Block converters are available widely (try Radio Shack for instance). John Whitmore
rpw3@rigden.wpd.sgi.com (Rob Warnock) (03/02/91)
In article <471@pyrite.nj.pyramid.com> dcm@pyrite.nj.pyramid.com (David C. Miller) writes: +--------------- | ...I find it frustrating to have to switch between the internal | and external tuner... | Cable Tuner +----- Channel 3 out | Descrambler | | Incoming cable with +-----+ v | scrambled signal on +------| |----+ | channel 28 / +-----+ \+----+ | --------------------+ | |------------+ | ^\ /+----+ | cable splitter -----+ +-----------------+ ^ | | | Device that blanks out channel 28 on --+ | straight through line, then map channel 3 | from the tuner to channel 28. +--------------- I have a similar but not identical problem. I don't have cable; I use the large outside antenna [no rotator] that came with the house I'm renting. It has a VHF/UHF mixer [inverse "splitter"] up on the antenna along with a 300ohm/75ohm balun, and feeds the composite signal into the house on a single 75ohm coax. My problem: Almost all the T.V. stations I'm interested in are in the direction the antenna points, except a couple, which are on the other side. And even there, all but one are strong enough that I get an acceptable signal on back-scatter from the hills "in front" of me. But the one weak signal on the "wrong" side is also one I'd really like to receive better. I could put up a second antenna pointing the other way, but have no easy way to control an antenna switch from the VCR. So the device *I'd* like to find would do something like this: Signal from the "front" antenna +-----------------+ \+----+ +-----+ Signal from the | ? |------+ VCR | "back" antenna /+----+ +-----+ +-----------------+ ^ | Passes all channels from "front" antenna, except for one, which it selects from "back" antenna. Any idea what to use for the little black box? -Rob p.s. The desired "back" channel is channel 54, and the closest desired "front" channels is channel 50 (which is, alas, also quite weak), so the filtering doesn't have to be *too* tight... ----- Rob Warnock, MS-1L/515 rpw3@sgi.com rpw3@pei.com Silicon Graphics, Inc. (415)335-1673 Protocol Engines, Inc. 2011 N. Shoreline Blvd. Mountain View, CA 94039-7311
monett_s@cho006.cho.ge.com (03/04/91)
In article <471@pyrite.nj.pyramid.com>, dcm@pyrite.nj.pyramid.com (David C. Miller) > > What I'm looking for is a way of adding a circuit that will > effectively unscramble the pay channel in place. The cable > company's converter unscrambles channel 28 and emits the clear > signal on channel 3. I want something to take this signal and > put it back on channel 28 and merge it back with the other cable > channels. The idea being that all but channel 28 comes straight > off the cable while channel 28 come in via the descrambler. > Even better than using a block converter is the device I have been using for the last 3 years. I got it from Radio-Shack. It has two inputs, one that accepts channel 3 and another set of RCA phono jacks that accept video and stereo audio from my VCR. I use the following setup. Incoming cable with scrambled signal /-----------------------------\ on channel 28 / \ output to ------- SPLITTER SPLITTER -- "house" \ +---------+ +----+ / cable, includ- \---| DESCRAM |--------| | / ing VCR +---------+ | BB |--/ | | video and audio "line" outputs from VCR --| | +----+ The Black-Box (I don't remember it name, look in the current Shack catalog) converts the line signal to channel 17 UHF and the channel 3 signal from the descrambler to channel 65 UHF. With this setup I can view channel 2-13 plus the currently selected pay channel plus the VCR on any TV in the house. My VCR is on the "house" cable so it can also be setup for any of these channels. -- ----------------------------------------------------------------------------- Steve Monett monett_s@cho006.cho.ge.com GE-Fanuc; Charlottesville, VA