mikey@trsvax.UUCP (12/27/84)
Does anyone on the net know anything about the proposed format for the networks broadcasting in stereo? The latest info that I got is that NBC has been sporadically broadcasting stereo of the Tonight Show since July 26, and that ABC only broadcast selected cuts of the Olmypics in stereo. I know that PBS is planning on nationwide stereo before the end of 85. I just bought a Beta HiFi. It doesn't make sense to me to go buy a stereo TV receiver. I'm going to run raw video to my TV (after I gut the tuner, which is shot anyway). Since the Beta will always be set to channel 3 output, I want to make a separate decoder box so I can run the stereo signals into the Beta in the simulcast mode and to the audio amplifier for listening. So far I haven't been able to find anything out about the format of the encoding. Most people I've talked to THINK it is either similar to or the same as FM stereo. If not the same, just a different pilot frequency with extended frequency response. Does ANYBODY know? mikey at trsvax
cem@intelca.UUCP (Chuck McManis) (02/15/85)
Ok, so now TV20 in the Bay Area is going to broadcast in Stereo and my
stereo ready Sony, has one Mux Out plug on the back. Does anyone know
how it is multiplexed? A friend thinks that it has one channel superimposed
over the other with an FM Subcarrier. If this is the case two questions arise.
a.) What is the subcarrier frequency and
b.) What is the lowest frequency of the modulated subcarrier so that I can
figure out where to put the Low Pass cutoff on the other channel.
Thanks in advance.
--Chuck
--
- - - D I S C L A I M E R - - -
{ihnp4,fortune}!dual\ All opinions expressed herein are my
{qantel,idi}-> !intelca!cem own and not those of my employer, my
{ucbvax,hao}!hplabs/ friends, or my avocado plant. :-}doug@terak.UUCP (Doug Pardee) (02/18/85)
One of the national magazines (Radio-Electronics) is running a series
of articles describing the technical points of Stereo TV. Here are
the major points:
1) The system is similar to FM stereo (L+R baseband, pilot carrier,
L-R subchannel DSBSC modulated on 2 X pilot frequency, other
subchannels authorized);
2) The pilot carrier == the horizontal sweep frequency (15734 KHz);
3) The L-R subchannel (but *not* the L+R baseband) is compressed
using dbx(tm).
The FCC was explicit that this is not *the* Stereo TV system, and that
other systems could be introduced in the future. But this is the only
approved system to date, there are no signs of any other system in the
works, and the FCC did specify that any future incompatible systems
must not transmit a pilot carrier at 15734, as this pilot is the
"signature" of the current system.
--
Doug Pardee -- Terak Corp. -- !{hao,ihnp4,decvax}!noao!terak!dougfish@ihlpg.UUCP (Bob Fishell) (02/18/85)
> Ok, so now TV20 in the Bay Area is going to broadcast in Stereo and my > stereo ready Sony, has one Mux Out plug on the back. Does anyone know > how it is multiplexed? A friend thinks that it has one channel superimposed > over the other with an FM Subcarrier. If this is the case two questions arise. > a.) What is the subcarrier frequency and > b.) What is the lowest frequency of the modulated subcarrier so that I can > figure out where to put the Low Pass cutoff on the other channel. > *** REPLACE THIS MESS WITH YOUR LINEAGE *** The stereo tv system approved by the FCC last year uses an L-R signal on a subcarrier, similar to the method used for FM stereo. However, the L-R signal is companded a la dbx, so just peeling it off the subcarrier won't do the trick. I don't think the compander is weighted the same as any of dbx' commercial NR units, either. You'll have to buy the decoder or wait for the inevitable kits to come out. /_\_ Bob Fishell ihnp4!ihlpg!fish
wmartin@brl-tgr.ARPA (Will Martin ) (02/21/85)
A local station (KPLR-TV, Ch. 11, independent) here in St.Louis has been touting their stereo movie broadcasts. During their premiere, M*A*S*H, I plugged in my Capri tunable SCA demodulator, and found no multiplexed subcarriers at all at the earphone outlet. That might mean a different system, or it might mean sharp high-cut filtering at the earphone jack. (Though most FM radios will produce SCA detection at the earphone jack, especially if you crank any tone controls to "full-treble".) Will
karn@petrus.UUCP (02/21/85)
> 1) The system is similar to FM stereo (L+R baseband, pilot carrier, > L-R subchannel DSBSC modulated on 2 X pilot frequency, other > subchannels authorized); > 2) The pilot carrier == the horizontal sweep frequency (15734 KHz); This is very interesting. It's essentially identical to the way that the sound is encoded under one of the broadcast pay-TV systems. I wonder if WNBC in New York is running stereo, that station has always had a strange effect on my TV set's magic box... Phil
rb@houxn.UUCP (R.BOTWIN) (02/22/85)
As far as I know WNBC - NY is the first to try stereo in the area.... The Tonite show (Johnny Rivers) was the premier trial.
doug@terak.UUCP (Doug Pardee) (03/01/85)
> This is very interesting. It's essentially identical to the way that the sound > is encoded under one of the broadcast pay-TV systems. I recall reading in Electronic Engineering Times that Stereo-TV also conflicts with many (most? all?) cable-TV systems. From my meager understanding, it doesn't matter much what kind of system your cable-TV uses, because "it's always something -- if it's not interfering with the descrambling signals, it's being lopped off by the converter box" or some such. Sounds like stereo-TV via cable might be a ways off. -- Doug Pardee -- Terak Corp. -- !{hao,ihnp4,decvax}!noao!terak!doug
lionel@babel.DEC (Steve Lionel) (10/05/85)
Dick Grantges complained that WNBC in New York showed programs denoted as being "in stereo", but were not broadcast as such by WNBC. The Boston NBC affiliate, WBZ-TV, is broadcasting in stereo and I have been receiving the new NBC shows in true stereo. Note that the "in stereo" display at the beginning of the shows is provided by the NBC network and means that the program source is in stereo. Whether you can actually receive it in stereo depends on your local broadcaster. WBZ is doing a fantastic job of broadcasting a high-quality MTS signal. While the program content of last week's "Amazing Stories" was low, the stereo sound was fantastic. I use a Sony SL-2700 VCR with MPX output hooked up to a Proton 690 MTS decoder. Steve Lionel
rfg@hound.UUCP (R.GRANTGES) (10/06/85)
[] Much as I hate to say it, Dick Grantges is sometimes an idiot. In this case, he forgot which buttons did what on his Sony MlV(?)1100 Stereo Decoder, and he misplaced the instructions. Also, he never watches Steve Carson (well, hardly ever). Last night he tried again and discovered actual stereo on channel 4 (WNBC-TV) in the program "Misfits of Science" and its attendant commercials. It didn't have very much separation, but it was stereo and beat the mono on the other channels all hollow, except CH 13 (Public) which was also stereo at the moment. The commercials sounded pretty neat in stereo. Dick Grantges (hound!rfg) who does <not> recommend the Sony MLV-1100. -- "It's the thought, if any, that counts!" Dick Grantges hound!rfg