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Quadraphonic Broadcast Transmitting Equipment

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Soundfield

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^^^(Discrete) Quad albums/music sources - (2nd paragraph RCA2.pdf)
IIRC, the WEA group expected that ~50% of their albums would be
(discrete) Quad soon after selecting CD-4.
Of course, both SQ and QS encoded Quad albums could be decoded
and broadcast with the (Dorren) discrete Quad FM system.
Kirk Bayne
But, as I said it would be commercially senseless to create a discrete FM system just to transmit decoded or demoduated non-discrete source material.
 
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Soundfield

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There were obviously many nails in the discrete FM coffin - timing, lack of source material, cost to both broadcaster and listener and questionable technical performance. It never really stood a chance.
 
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kamranv

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Does anyone know if any company has manufactured any Quadraphonic Broadcast Transmitting Equipment in a 2-2-4 pattern; that would have been equally compatible with Conventional 2-Channel Stereo and Quadraphonic Stereo?
The free software that we made (with a lot of help) could help you to broadcast QS. Check out this post to get the info:::: SQ/QS Matrix Decoding Software

As stated in other replies matrix encoding works over FM. Folks on this very forum could hear your broadcast through all of their excellent vintage equipment and of course the best experience is the involve decoder.

Also, it’s not perfect but pretty much every receiver built from 2001 to now has dolby pro logic II in it. People can use “music mode” to listen to your broadcast. It’s a pretty massive install base and most people don’t even know it’s possible.
 

J. PUPSTER

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A little off subject, sorry! But say someone wanted to produce an online service of taking Quad discrete source material and encoding to QS for online Involve decoding, is that something that’s possible? Doesn’t Bill Brent do that for his show?
 

MidiMagic

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They DID broadcast in matrix quad.

The Dorren system was intended to broadcast demodulated CD-4 and to broadcast tapes.

A QS, SQ, or EV encoder could encode and broadcast a demodulated CD-4 record or discrete tape.

The big drawback to the Dorren system was it caused the Subsidiary Communications Authority (SCA) broadcasts to be removed from the FM station. These were the systems that provided background music in stores and banks and made money for the stations that had it.

The Zenith system was better in that it did not remove the SCA signals.

The strange thing is that RCA, which championed discrete, proposed a three-channel system for FM to keep SCA.

TV is still broadcasting in Dolby Surround. I am listening to it right now.
 

kfbkfb

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Regarding post #12:
ABC Records used Sansui QS (also called RM - Regular Matrix)
IIRC, Sansui didn't require a license fee to use QS.

It's unusual that another part of the ABC company (radio)
wouldn't also use QS.


Kirk Bayne
 

kfbkfb

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IIRC, in the mid-1970s, CBS (SQ) went after Sansui (QS), claiming that,
in some cases, the way a QS encoder was wired into an FM stereo
station reduced the L/R stereo separation to ~8dB, violating the
FCC rule that required ~30dB separation throughout the station
systems.

(I remember a front page headline about this, so far, I haven't
found that issue of Billboard)


Kirk Bayne
 

Doug G.

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Ah, the old "Titanic" analogy. How, exactly, would have discrete four channel broadcasting been like the Titanic, especially if quadraphonics, in general had been successful?

Doug
 

Soundfield

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It doesn't do any good to be seduced by the apparent benefits of a particular technology in isolation - you need to take a systems engineering approach to establish its viability in the real world. Such an holistic approach generally allows you to avoid such embarrassing situations as :

Purveyor of Quad Transmitting Equipment (PQE) - Hi, good afternoon, I’ve got a great new technology for your station!
Radio Station Owner (RSO) - Oh really?
PQE – Yes, we can convert your transmitting system to fabulous discrete four channel so you can transmit in quad!
RSO- But I can already broadcast in quad.
PQE- Ah yes, but that’s using those awful matrix records, our system allows you to broadcast four lovely, pure discrete channels.
RSO - Oh great, where do I get these discrete recordings then?
PQE- Err, well there aren’t any really, but it gives you the opportunity to get out into your community and to make your own. All you need to do is buy some four channel recording and editing equipment and hire a few bands.
RSO - I don’t have the budget for that.
PQE – Well you can always decode matrix records and use them.
RSO- You said they were awful, will your system improve them for my audience?
PQE- Not as such, but they won’t have to buy a matrix decoder to enjoy them.
RSO - Will they have to buy anything?
PQE – Well, err, yes a whole new receiver. They don’t exist yet but I’m told they will be very cheap.
RSO – And how extensive would the modifications be to my existing transmitter?
PQE - Oh, nothing much, just the replacement of the entire modulation deck. And perhaps the output stage. And the studio feed to the transmitter will have to upgraded….
RSO – But it’s a net improvement, right?
PQE – Oh sure, well, your coverage area will probably drop off a wee bit and some listeners may suffer more multipath problems. Then there’s the signal to noise issue....
RSO – My secretary will show you out.
 

Q-Eight

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From a systems engineering perspective that would have been complete madness.
Not at all. Play CD-4 record in studio, demodulate it in the studio, broadcast the 4 discrete output channels. Easy peasy, Lemon Squeezy.
The Dorren system would have done this. Problem was, it was not adopted by the FCC until 1983.
They would not be transmitting the CD-4 signal and having the listener demodulate. That's my brother, Crazy Talk.

The hope was that once all the pieces fell into place, the music industry would put on their big boy pants and ALL future releases would be in Quad. That's why all three formats are still stereo compatible. A title would be mixed into 4-channel, that when downmixed to 2-channel, still provided the listener with an appealing soundstage but also satisfied the creative impulses of the creator. A win-win.

But, it never happened. There simply was not enough time to put all the pieces in place. Remember, Quad was only a major-market point for about 5 years (1971-1976).
That's barely enough time to get 20 people to agree on pizza toppings, let alone reorganize established industries into something new.

Happens all the time. In the automotive world, we had reliable mechanical fuel injection (on American cars) by 1956 (basically, Throttle-Body Injection (TBI). We had electronic, multi-port fuel injection by 1958 (MPFI). It would take into the 80's before TBI was adopted and well into the 90's before MPFI became the norm.

If Quad had been given even 10 GOOD years on the market, that may have been enough time to shift things around. Quad Cassette, Quad Elcaset and Quad CD may have also been actual, commercially available devices in that time frame.
 
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Soundfield

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Not at all. Play CD-4 record in studio, demodulate it in the studio, broadcast the 4 discrete output channels. Easy peasy, Lemon Squeezy.
Oh yes of course, the famously robust CD4 system - ideally suited to being used and abused in a radio studio environment. And of course there were all of those dozens of discs available, well worth building an entire transmission network for, they could have kept a station going for several hours.
 

MidiMagic

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The station is broadcasting CD-4 records:

- The secretary come in with a news bulletin and drops her compact. "Snap crackle pop".

- Someone sprays an air freshener. Sandpaper quad.

- The CD-4 records stop working quickly because the DJs can't be bothered with the special care needed.
 

Doug G.

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The station is broadcasting CD-4 records:

- The secretary come in with a news bulletin and drops her compact. "Snap crackle pop".

- Someone sprays an air freshener. Sandpaper quad.

- The CD-4 records stop working quickly because the DJs can't be bothered with the special care needed.
Silly.

Doug
 

Q-Eight

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Oh yes of course, the famously robust CD4 system - ideally suited to being used and abused in a radio studio environment. And of course there were all of those dozens of discs available, well worth building an entire transmission network for, they could have kept a station going for several hours.
You know, if we'd have had this discussion about 10 years ago, I'd have probably shared your skepticism, and to be fair, yeah, some DJ's were notoriously hard on equipment.
BUT, when CD-4 is set up correctly, in my experience I can say it is quite robust and user friendly. I would imagine there would be a station engineer who would make sure the CD-4 equipment functioned properly day-to-day. Not to mention, CD-4 was really only a second-generation Quad format. It may have only lasted at a radio station until Quad Elcaset or Quad CD came along - both of which, were explored at one point in time. I'm sure even the radio station "Cartridge" could've been turned into a 4-channel system quite easily.

Matter of factly, now that I think about it.... there is a recording of I believe the FIRST Quad over-the-air broadcast out there, somewhere using the Dorren system and they played a few songs from CD-4 LP's. So, it may not have been very long-lived, but it would have been adeuqate for a few years until something better came along.

Trust me, I fought with CD-4 for years. I thought it was garbage until one final hail-Mary move, I shelled out big bucks for a cartridge/stylus combo and gave my demodulator the tune-up it needed and Ho Lee Fook.... I was sold on CD-4. LP's that I'd nearly thrown away because they couldn't hold carrier lock past the second song now give me FULL SIGNAL right to the point where the light goes off. (I have a Technics demod and it has a meter on front that shows signal strength). I like to fiddle with it from record to record, but I'm pretty much at the point where it's a "Set it and Forget it" system. Ron Popeil would be proud.

And, I've got over 80 CD-4 LP's myself. Keeping in mind it was probably the shortest lived of the formats debuting in 1973 and running through 1975 maybe into early '76 on a few RCA titles.

Honestly, it's not the fragile daffodil you think it is. We're speaking hypothetically here and I'm sure had 4-channel had a more mainstream appeal, there would've been hundreds of CD-4 LP's just like there are crappy, horrible SQ records. :LOL:
 
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