DORREN QUADRAPLEX: THE LONG WAIT
In the fall of 1971, Willamette Broadcasting Company owner Walter Kraus and key staff members met with James Gabbert of KIOI (K-101) in San Francisco and returned to Lake Oswego very excited. K-101 had successfully transmitted true four-channel audio for the first time on a single FM station using Dorren Quadraplex, a process invented by Louis "Lou" Dorren. The FCC was concerned, however, with certain technical issues that had to be resolved before it would give Quadraplex its blessing.
KQIV had hoped to be the Portland-area station chosen to participate in a long-term, multi-market field test of Quadraplex. In anticipation that full-scale testing would be approved by the FCC, Willamette Broadcasting went forward and blanketed the area with outdoor billboards proclaiming, "Credibility is back. KQ4 Quadraphonic FM 107."
Then, about a month before KQ4's on-air debut, the FCC issued the following:
792
Federal Communications Commission Reports
BEFORE THE FEDERAL COMMUNICATIONS COMMISSION
WASHINGTON, D.C. 20554
Discrete Four-Channel Multiplex Transmissions
Report No. 10851
August 9, 1972
THE COMMISSION ISSUED THE FOLLOWING PUBLIC NOTICE:
Broadcast Action
Discrete Four-Channel Multiplex Stereo Transmission Requires Specific Authority, FCC Rules
FM broadcast stations may not engage in discrete four-channel multiplex transmission without specific authorization, the Commission has ruled.
Pacific FM, Incorporated, licensee of FM station KIOI, San Francisco, Calif., asked for the Commission ruling. Pacific FM had previously obtained temporary experimental authority to field test the Dorren Quadraplex System. It contended that the Dorren system was compatible with present rules governing two-channel stereo and that music transmitted by this method could be offered to the public without further authorization.
The Commission said that the four-channel stereo systems being sold today are "pseudo-enhancement devices relying on a phase-differential principle to achieve four-channel audio effects," and may be used within the FCC's present FM stereo transmission standards without specific authorization.
The Commission cautioned, however, that these "pseudo systems" should not be confused with discrete four-channel multiplex transmission, like the Dorren system, which has been authorized only on a limited experimental basis. Section 73.322(c) of the rules permits the transmission of only a single sine subcarrier, where the Dorren system requires the addition of a cosine subcarrier, the FCC noted. The Commission also indicated that, since the Dorren system might exceed present limits on modulation, existing protection ratios for co-channel and adjacent channel stations would have to be reviewed before the system could come into general use.
Action by the Commission August 9, 1972, by letter. Commissioners Robert E. Lee (Acting Chairman), H. Rex Lee and Wiley, acting as a Board.
72 F.C.C. 2d
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On August 1, 2007, I received this from Lou Dorren: "We actually won as the US national standard. It took the FCC so long to approve (March of 1986) that the industry was already dead!"
KQIV had hoped to be the Portland-area station chosen to participate in a long-term, multi-market field test of Quadraplex. In anticipation that full-scale testing would be approved by the FCC, Willamette Broadcasting went forward and blanketed the area with outdoor billboards proclaiming, "Credibility is back. KQ4 Quadraphonic FM 107."
Then, about a month before KQ4's on-air debut, the FCC issued the following:
792
Federal Communications Commission Reports
BEFORE THE FEDERAL COMMUNICATIONS COMMISSION
WASHINGTON, D.C. 20554
Discrete Four-Channel Multiplex Transmissions
Report No. 10851
August 9, 1972
THE COMMISSION ISSUED THE FOLLOWING PUBLIC NOTICE:
Broadcast Action
Discrete Four-Channel Multiplex Stereo Transmission Requires Specific Authority, FCC Rules
FM broadcast stations may not engage in discrete four-channel multiplex transmission without specific authorization, the Commission has ruled.
Pacific FM, Incorporated, licensee of FM station KIOI, San Francisco, Calif., asked for the Commission ruling. Pacific FM had previously obtained temporary experimental authority to field test the Dorren Quadraplex System. It contended that the Dorren system was compatible with present rules governing two-channel stereo and that music transmitted by this method could be offered to the public without further authorization.
The Commission said that the four-channel stereo systems being sold today are "pseudo-enhancement devices relying on a phase-differential principle to achieve four-channel audio effects," and may be used within the FCC's present FM stereo transmission standards without specific authorization.
The Commission cautioned, however, that these "pseudo systems" should not be confused with discrete four-channel multiplex transmission, like the Dorren system, which has been authorized only on a limited experimental basis. Section 73.322(c) of the rules permits the transmission of only a single sine subcarrier, where the Dorren system requires the addition of a cosine subcarrier, the FCC noted. The Commission also indicated that, since the Dorren system might exceed present limits on modulation, existing protection ratios for co-channel and adjacent channel stations would have to be reviewed before the system could come into general use.
Action by the Commission August 9, 1972, by letter. Commissioners Robert E. Lee (Acting Chairman), H. Rex Lee and Wiley, acting as a Board.
72 F.C.C. 2d
----------
On August 1, 2007, I received this from Lou Dorren: "We actually won as the US national standard. It took the FCC so long to approve (March of 1986) that the industry was already dead!"
posted by J. R. Miller at 10:07 AM
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