[rec.video] *** CABLE TV + VCR + TV ***

geoff@cs.warwick.ac.uk (Geoff Rimmer) (04/30/89)

This is a question about CABLE TV and how it interfaces with a VCR and TV.


Here in the UK, I have found no way to do either of the following:

a) Program the VCR's timer to switch cable channels by itself.

b) Record one cable channel while watching another cable channel.


With regular TV, there is no problem.  We just have our 4 channels
coming into the VCR and the VCR can switch between them at its
leisure.  Meanwhile, the 4 channels are then fed into the TV, where
I can choose to watch any of the 4 channels.


4 channels	  +----------+		4 channels	+----------+
=================>|  V C R   |=========================>|   T V    |
=================>|          |=========================>|          |
		  +----------+				+----------+
		(tapes channel 2)			(shows channel 4)

Now, when we bring cable TV into it, we get this:

20 channels    +----------+            +----------+               +----------+
==============>|  CABLE   | 1 channel  |   VCR    |   1 channel   |   TV     |
==============>|  RCVR    |===========>|          |==============>|          |
==============>|          |            |          |               |          |
               +----------+            +----------+               +----------+

The only way to switch cable channels is by using the cable receiver.
This then tunes into one frequency, and that is the *only* channel to
be sent to the VCR and TV.

The only way I know of being able to watch channel x while taping
channel y, is to buy a second cable receiver.  In fact this is what
my local cable company advised me to do.  (At an extra cost to me of
#7 = $12 a month of course!)

However, this does not get round the other problem: I cannot program the
VCR to record

	channel 10 from 6pm -> 7pm
then	channel 15 from 8pm -> 9pm

without me standing by the cable receiver and switching it manually!

My understanding of what the cable receiver does is based purely on
observation:

I know it takes 20 channels as input, checks the channel it is set to,
say ch 8.  It then outputs this channel on a particular frequency - it
doesn't matter whether it is channel 8 or channel 20 - it still comes
out on one particular frequency.

Now, the thing I can't get straight in my head is: if there are 20
channels coming in on different frequencies, why can't the damn box
give me those 20 channels (or maybe 15, if I haven't paid for the
movie channels) out also on *different* frequencies???  Is a box that
meets these specifications particularly difficult or expensive to make?

Is such a box in existence?

If so, all my problems would be solved and I would be able to lead a
happy and contented life, in the knowledge that I could leave my VCR
to do its job of switching channels, taping something, switching to
another channel, taping something else, etc etc.

Can somebody please help me!!!

Geoff

	/---------------------------------------------------------------\
	|	GEOFF RIMMER  - Friend of fax booths, ANSI C, PCBH,	|
	|			phone *numbers*	& MPFC & CABLE TV	|
	|	email	: geoff@uk.ac.warwick.emerald			|
	|	address : Computer Science Dept, Warwick University, 	|
	|		  Coventry, England.				|
	|	PHONE	: +44 203 692320 (10 lines) If I'm out please	|
	|			   leave a message with my secretary.	|
	|	FAX	: +44 865 726753				|
	\---------------------------------------------------------------/

brown@astroatc.UUCP (Vidiot) (05/01/89)

In article <1796@ubu.warwick.UUCP> geoff@cs.warwick.ac.uk (Geoff Rimmer) writes:
<
<This is a question about CABLE TV and how it interfaces with a VCR and TV.
<
< [...]
<Now, the thing I can't get straight in my head is: if there are 20
<channels coming in on different frequencies, why can't the damn box
<give me those 20 channels (or maybe 15, if I haven't paid for the
<movie channels) out also on *different* frequencies???  Is a box that
<meets these specifications particularly difficult or expensive to make?
<
<Is such a box in existence?

No, such boxes don't exist, as they are too expensive to build.  Here in the
States, anyone who buys a pay channel (that is scrambled) also has the 
programmability of their equipment shot-to-hell.  I get the impression that
you don't get any of the pay channels.

Since I am not in the UK, I don't know the frequencies that are used on the
cable system.  I do know that over-the-air channels are in what is known
as the UHF band.  These frequencies are very though to put through cable over
any distance.  I wouldn't be surprised if UK cable companies use the VHF band
like we do.  If they do you are SOL.

But, if they are using the same channels that are used over-the-air, then
you can check that out by plugging the incoming cable directly into your VCR.
Tune the VCR through all of the available UHF channels.  If you can get what
you want, just remove the cable box.  If you can't get anything, then the
VHF frequencies are used.

I realize this may not help too much, but hopefully it will give you a clue.
-- 
	        harvard\     att!nicmad\
Vidiot            ucbvax!uwvax..........!astroatc!brown
	        rutgers/  decvax!nicmad/
	ARPA/INTERNET: brown%astroatc.UUCP@spool.cs.wisc.edu

sparks@corpane.UUCP (John Sparks) (05/01/89)

In article <1796@ubu.warwick.UUCP> geoff@cs.warwick.ac.uk (Geoff Rimmer)
writes:
>
>This is a question about CABLE TV and how it interfaces with a VCR and TV.
>Now, when we bring cable TV into it, we get this:
>
>20 channels    +----------+            +----------+               +----------+
>==============>|  CABLE   | 1 channel  |   VCR    |   1 channel   |   TV     |
>==============>|  RCVR    |===========>|          |==============>|          |
>==============>|          |            |          |               |          |
>               +----------+            +----------+               +----------+

I just got cable and was in the same situation. I found a couple of solutions:

1> If you don't have any scrambled channels to worry about, the simplest
solution would be to eliminate the box and run the cable into the VCR, if it
can handle 20 stations.

2> If you do have some scrambled channels, then you will still need the box for
those channels. Run the main cable into a 2 way splitter, then run one
output into the box. Get a video switchbox that has at least 3 inputs and
2 outputs (mine has 2 out and 5 in, two separate dials on the front, one
for each input. )
Run the other output of the splitter into the switch box. Run the output of
the cable box into another input of the switch box. Run the output of your
VCR into another input of the switch box. Hook one output of the switchbox
to the VCR's input, and the other output of the switch box to the TV.

You can now select for input to your TV : cable, cable box, VCR.

Your can now select for input to your VCR: cable, cable box. (you can't select
your VCR output as input to your VCR, even though it also runs into the switch
box  :-)   ).


cable   36CH     splitter -----       1 ch    -------
-------------------------| box |-------------|switch |-------------- TV
                    |     -----       36 ch  |       |
                    |________________________| box   |------ vcr ----
                                             |       |              |
                                     ------- |_______|              |
                                    |_______________________________|

The switch lets each dial select from the various inputs, The exception being
that the VCR switch doesn't select VCR as input. I got mine at radio Shack.
Not that I particularly care for Radio Shack, but the price was right and
it does the job. ($29.95 U.S.). 

Now I can use my vcr for taping any channel with the timer, with the exception
of the scrambled channels. If I want to record one of those I have to set the
VCR to get its input from the cable box and set the cable box on the 
scrambled channel. The TV switch usually stays on VCR. But it is cable ready
so if I want to, while I am taping something on the VCR, I can set the TV to 
get it's input from the cable or cable box and watch something else.

Plus I have inputs left over so I can hook my computer into this mess. 

Not bad. The only compromise is that I have to manually switch the 
scrambled channels in order to tape them.
-- 
John Sparks   |  {rutgers|uunet}!ukma!corpane!sparks | D.I.S.K. 24hrs 1200bps
[not for RHF] |          sparks@corpane.UUCP         | 502/968-5401 thru -5406 
Don't worry if you're a kleptomaniac, you can always take something for it.

boettche@cat17.CS.WISC.EDU (Michael Boettcher) (05/02/89)

In article <1825@astroatc.UUCP> brown@astroatc.UUCP (Vidiot) writes:
>In article <1796@ubu.warwick.UUCP> geoff@cs.warwick.ac.uk (Geoff Rimmer) writes:
><
><This is a question about CABLE TV and how it interfaces with a VCR and TV.
><
>< [...]
><Now, the thing I can't get straight in my head is: if there are 20
><channels coming in on different frequencies, why can't the damn box
><give me those 20 channels (or maybe 15, if I haven't paid for the
><movie channels) out also on *different* frequencies???  Is a box that
><meets these specifications particularly difficult or expensive to make?
><
><Is such a box in existence?
>
>No, such boxes don't exist, as they are too expensive to build.  Here in the
>States, anyone who buys a pay channel (that is scrambled) also has the 
>programmability of their equipment shot-to-hell.  I get the impression that
>you don't get any of the pay channels.
>
I believe this is incorect.  Radio Shack sells a Cable Converter that puts
all the cable channels (A-Z) up on the UHF band.  This is for non-cable
ready tv's.  

What I think the box does is to convert all the cable channels to channel 
2 or 3, one at a time.  When a pay channel is selected, it also de-scrables
it.  

I am presently viewing cable on a non-cable ready TV with one of the Rad 
Shack converters, and have no problems.  My VCR is cable ready also, so I
really don't even need the converter.  I may be missing the point, but I 
don't think that there is any problem about recording on one channel while
watching another if your VCR is cable ready, or you have a converter.

Hope this isn't too far off, and is of some help.

Michael Boettcher    boettche@garfield.cs.wisc.edu

brown@astroatc.UUCP (Vidiot) (05/02/89)

In article <2652@puff.cs.wisc.edu> boettche@cat17.CS.WISC.EDU (Michael Boettcher) writes:
<In article <1825@astroatc.UUCP> brown@astroatc.UUCP (Vidiot) writes:
<>In article <1796@ubu.warwick.UUCP> geoff@cs.warwick.ac.uk (Geoff Rimmer) writes:
<><
<><This is a question about CABLE TV and how it interfaces with a VCR and TV.
<><
<>< [...]
<><Now, the thing I can't get straight in my head is: if there are 20
<><channels coming in on different frequencies, why can't the damn box
<><give me those 20 channels (or maybe 15, if I haven't paid for the
<><movie channels) out also on *different* frequencies???  Is a box that
<><meets these specifications particularly difficult or expensive to make?
<><
<><Is such a box in existence?
<>
<>No, such boxes don't exist, as they are too expensive to build.  Here in the
<>States, anyone who buys a pay channel (that is scrambled) also has the 
<>programmability of their equipment shot-to-hell.  I get the impression that
<>you don't get any of the pay channels.
<>
<I believe this is incorect.  Radio Shack sells a Cable Converter that puts
<all the cable channels (A-Z) up on the UHF band.  This is for non-cable
<ready tv's.  

One cannot shift all the channels to the UHF band and descramble the scrambled
ones at the same time.  It just ain't done.  Maybe I didn't make myself clear
enough.  Here in the States, if one doesn't have the pay channels AND none of
the other channels are scrambled (some systems are tiered), then one just
removes the cable converter box and enjoys multi-channel capability.  If one
has a pay channel, the box is a must.

The Radio Shack unit (and others) moves all channels up to the UHF band,
starting with 2 and ending with W or later (if the bandwidth is large
enough).  These work well with non-scrambled systems.

<I am presently viewing cable on a non-cable ready TV with one of the Rad 
<Shack converters, and have no problems.  My VCR is cable ready also, so I
<really don't even need the converter.  I may be missing the point, but I 
<don't think that there is any problem about recording on one channel while
<watching another if your VCR is cable ready, or you have a converter.

The problem overseas may be a little different.  As I mentioned, if the
cable is truely UHF, then the user should be able to remove the cable box.
But if the cable is VHF, then he can't do much, as I don't believe the
broadband converters are available there.  There isn't the market as there
is here.  But I did forget about that thing.  It could be possible that
one of those would work there since they are not channel sensitive.  The
problem is finding one.

With more details from the original poster, we should be able to come up
with some kind of answer.

Thanks for reminding me about the VHF-UHF shifters.  I think mine is still
in a box downstairs someplace.
-- 
	        harvard\     att!nicmad\
Vidiot            ucbvax!uwvax..........!astroatc!brown
	        rutgers/  decvax!nicmad/
	ARPA/INTERNET: brown%astroatc.UUCP@spool.cs.wisc.edu

brown@astroatc.UUCP (Vidiot) (05/03/89)

In article <586@corpane.UUCP> sparks@corpane.UUCP (John Sparks) writes:
[... John describes a possible way to get around the problem ...]

As I mentioned in a previous message, the British cable system may be
VHF.  This means that the normal TV/VCR receivers won't work with direct
cable connections because the equipment only receives UHF.

One must keep this in mind when discussing overseas TV/Cable systems.
-- 
	        harvard\     att!nicmad\
Vidiot            ucbvax!uwvax..........!astroatc!brown
	        rutgers/  decvax!nicmad/
	ARPA/INTERNET: brown%astroatc.UUCP@spool.cs.wisc.edu

wheels@mks.UUCP (Gerry Wheeler) (05/05/89)

In article <1844@astroatc.UUCP>, brown@astroatc.UUCP (Vidiot) writes:
> As I mentioned in a previous message, the British cable system may be
> VHF.  This means that the normal TV/VCR receivers won't work with direct
> cable connections because the equipment only receives UHF.
> One must keep this in mind when discussing overseas TV/Cable systems.

Indeed.  I sent a reply to the original question to the fellow in the
UK, describing how we do things, and I mentioned "cable-ready TV".  He
pointed out that they have no such thing, so the cable company's box is
mandatory.  Would someone who knows care to outline what they really do
over there? From the above quote, I take it the TV stations are all UHF,
so the TV's all have UHF tuners, but the cable system sends only VHF. Is
this correct?
-- 
     Gerry Wheeler                           Phone: (519)884-2251
Mortice Kern Systems Inc.               UUCP: uunet!watmath!mks!wheels
   35 King St. North                             BIX: join mks
Waterloo, Ontario  N2J 2W9                  CompuServe: 73260,1043

dce@Solbourne.COM (David Elliott) (05/05/89)

In article <1836@astroatc.UUCP> brown@astroatc.UUCP (Vidiot) writes:
>The Radio Shack unit (and others) moves all channels up to the UHF band,
>starting with 2 and ending with W or later (if the bandwidth is large
>enough).  These work well with non-scrambled systems.

They can also work OK with a system with a minimum of scrambled channels.

What you can do is to wire up your system as follows:

	* Split the incoming signal, connecting one side to the
	  VCR VHF input and one to the cable box

	* Connect the output of the cable box to the VHF-UHF "block"
	  converter

	* Connect the output of the block converter to the UHF input
	  on the VCR

The result is that UHF channel 35 (or something like that) contains
the output of the cable box.  If you only have one scrambled channel,
you're set.  If you have more, you'll have to switch, but if there
aren't too many, it's ok (the bastards in my area scramble almost
everything, including the local broadcast channels!, and the
scrambled channel list changes every couple of weeks, seemingly at
random; I'm going with "wireless cable" pretty soon).

There are a couple of problems with this approach

	1. The quality of the VHF-UHF converted signal is not as
	   good as the original.  Thus, this is only a good
	   solution if you really want to record lots of shows
	   on different channels including the scrambled ones.
	   Otherwise, an inexpensive switch is a better idea
	   (hmm, how about a switch on a timer?).

	2. Some VCRs can't handle both CATV and UHF.  My old RCA
	   (VKT400, I think) worked fine, but my new Quasar can't
	   do this.

It seems to me that the cable companies would really benefit from
having a timer system built into the cable box.  I know that some
boxes have direct video out, and if you could combine that with
a camera pause switch, consumers could just leave the system on
record and let the box do the work of changing channels and
starting/stopping the recording.

-- 
David Elliott		dce@Solbourne.COM
			...!{boulder,nbires,sun}!stan!dce

brown@astroatc.UUCP (Vidiot) (05/05/89)

In article <899@mks.UUCP> wheels@mks.UUCP (Gerry Wheeler) writes:
<In article <1844@astroatc.UUCP>, brown@astroatc.UUCP (Vidiot) writes:
<> As I mentioned in a previous message, the British cable system may be
<> VHF.  This means that the normal TV/VCR receivers won't work with direct
<> cable connections because the equipment only receives UHF.
<> One must keep this in mind when discussing overseas TV/Cable systems.
<
<Indeed.  I sent a reply to the original question to the fellow in the
<UK, describing how we do things, and I mentioned "cable-ready TV".  He
<pointed out that they have no such thing, so the cable company's box is
<mandatory.  Would someone who knows care to outline what they really do
<over there? From the above quote, I take it the TV stations are all UHF,
<so the TV's all have UHF tuners, but the cable system sends only VHF. Is
<this correct?

I was making an educated guess on the cable channels used, ie, VHF vs UHF.
The over-the-air channels are definately UHF, which range from 471.25 to
855.25 MHz (visual).
-- 
	        harvard\     att!nicmad\
Vidiot            ucbvax!uwvax..........!astroatc!brown
	        rutgers/  decvax!nicmad/
	ARPA/INTERNET: brown%astroatc.UUCP@spool.cs.wisc.edu

sparks@corpane.UUCP (John Sparks) (05/06/89)

<2652@puff.cs.wisc.edu> <1836@astroatc.UUCP>
Sender: 
Reply-To: sparks@corpane.UUCP (John Sparks)
Followup-To: 
Distribution: world
Organization: Corpane Industries, Inc.
Keywords: 
[my solution to use a splitter and switch box to run cable into vcr and tv]

> [vidiots reply that I should have considered that British TV is UHF]

I don't understand the problem. If British cable is on UHF instead of VHF,
then aren't their VCR's cable ready and made to pick up *uhf*? 
Most VCR's in the states are cable ready for US cable. I assumed  that
British VCR's would be set up for British cable.

If this is the case then my solution still stands. Run the cable directly
to the VCR, or if he has movie channels (scrambled), then use a splitter and
a switch box to select whether or not the vcr gets a direct cable feed or
a feed from the box. 




-- 
John Sparks   |  {rutgers|uunet}!ukma!corpane!sparks | D.I.S.K. 24hrs 1200bps
[not for RHF] |          sparks@corpane.UUCP         | 502/968-5401 thru -5406 
Life is like an onion: you peel off layer after layer, then you find
there is nothing in it.

brown@astroatc.UUCP (Vidiot) (05/07/89)

In article <602@corpane.UUCP> sparks@corpane.UUCP (John Sparks) writes:
<<2652@puff.cs.wisc.edu> <1836@astroatc.UUCP>
<Sender: 
<Reply-To: sparks@corpane.UUCP (John Sparks)
<Followup-To: 
<Distribution: world
<Organization: Corpane Industries, Inc.
<Keywords: 
<[my solution to use a splitter and switch box to run cable into vcr and tv]
<
<> [vidiots reply that I should have considered that British TV is UHF]
<
<I don't understand the problem. If British cable is on UHF instead of VHF,
<then aren't their VCR's cable ready and made to pick up *uhf*? 
<Most VCR's in the states are cable ready for US cable. I assumed  that
<British VCR's would be set up for British cable.

It is possible that British cable is UHF, but very unlikely due to the problems
of trying to transmit UHF frequencies via cable.

Cable is new to the British, so the advent of Cable-Ready VCRs is also going
to be new.  I wouldn't be surprised if there won't be VCRs showing up with
both cable and UHF frequency tuners in the near future.
-- 
	        harvard\     att!nicmad\
Vidiot            ucbvax!uwvax..........!astroatc!brown
	        rutgers/  decvax!nicmad/
	ARPA/INTERNET: brown%astroatc.UUCP@spool.cs.wisc.edu

lfog@PacBell.COM (Lee Fogel) (05/09/89)

This subject seems to have digressed a bit from the original problem,
which was how to come up with a way to record multiple cable channels
when a VCR is required to take its signal from a cable company's
converter box.  I think I may have come across a partial solution in
the form of a Radio Shack "Universal Remote Control With Five Built-In
Timers".  It's called the Model 150, and I saw it advertised for $69.95.

Apparently, It can remember up to 119 steps of remote control functions and
has 5 weekly timers that can be used to turn on and operate whatever
components whose remote control functions are programmed into it.
Although this would not solve the problem of viewing one cable channel
while recording another, it seems that it should enable me to program
the recording of any combination of TV programs while I'm away, as long
as the programs don't occur at the same time.

Does anyone out there have any experience using this thing?  It looks
like it could have a lot of potential uses.

- Lee