2 FCC Red Vol.5 Federal Communications Commission Record FCC 87-27
Before the
Federal Communications Commission
Washington D.C. 20554
MM Docket No. 87-6
In the Matter of
Amendment of Part 7
to Authorize the use of
Multiple. Synchronous
Transmitters by AM
Broadcast Stations
NOTICE OF INQUIRY
Adopted January 15, 1987; ReIeased March 3, 1987
By the Commission:
I. INTRODUCTION
1. This action initiates a J'otice of Inquiry (Inquiry ) into
the use of multiple. synchronous transmitters to enhance
and extend the signal coverage of AM broadcast stations.
In April 1986. the Commission released the Mass Media
Bureau's Report on the Status of i/ic AM Broadcast Rules.
RM-5532. (Report ).' The Report discussed. among other
things. the use of multiple transmitters. Of the various
uses of multiple transmitters discussed, the application of
"synchronous transmitters" has prompted the most inter-
est as a means of providing immediate benefits. Thus, this
proceeding will initially focus only on issues primarily
related to the use of synchronous transmitters. Synchro-
nous transmitter systems involve the use of two 01. more
broadcasting transmitters on the same frequency in neal
geographical proximity. broadcasting the same program
material. They employ precision carrier frequency and
phase control in order to minimize mutual interference.
Other uses ot multiple transmitters will he considered in
other rule making actions where appropriate.
2. Although there has been much interest expressed
regarding the use of synchronous networks, the Commis-
sion has concluded that ii is necessary to develop a more
complete record on the several related technical and
non-technical issues before proposing specific rules. In
addition to this Inquiry, the Commission has encouraged
applications for experimental authorizations to develop
technical data.2 Additionally, the Federal Communica-
tions Commission Radio Advisory Committee is encour-
aged to study these issues and to report its
recommendations to the Commission.
II. BACKGROUND
3. Conventional methods for enhancing and extending
the service area of an AM broadcast station typically
called for increasing the transmitter power, designing a
directional antenna system to improve service in a desired
direction, relocating the station, or any combination of
these. However, the crowded conditions that now exist in
the AM band limit the opportunities for such changes
without creating objectionable interference. MQreovel.
these conventional methods do not always provide sta-
tions with sufficient economic flexibility to improve their
service to all areas. The use of additional transmitters that
simultaneously broadcast the programs of a primary origi-
nating station is an effective and economical method that
could be applied in some circumstances to improve and
extend a station's service area.
4. The technology relating to synchronized transmitters
was discussed early in the United States in a paper written
by Charles B. Aiken of Bell Telephone Laboratories in
i933, In 1937. the first experimental authorization to
explore this technology in the U.S. was granted to radio
station WLLH. Lawrence. Massachusetts. which has con-
tinued its synchronous operations to this day. Similar
experiments have been conducted in Boston (WBZ).
Charlotte. North Carolina (WBT). Cincinnati. Ohio
(WSAI). and in Washington. D.C. (WINX and WWDC).
Synchronized groups of transmitters have been used in
the AM band on a large scale in Europe for many years.
and more recently in Japan. These foreign operations
have been based upon the same theoretical bases as the
earlier Uniied States operations.4 The results of the inter-
national experience have been largely consiStent with
those obtained in the United States. These operations have
further demonstrated the feasibility of synchronous oper-
ations and have confirmed earlier predictions of perfor-
mance to be expected from different system designs.
5. There are numerous examples where such
applications could be made. For instance, additional
transmitters simultaneously broadcasting thc programs of
a primary station could he located in or near the areas
where service improvements are desired. Such service
enhancements could be instituted along major highways
in order to permit a station to serve the traveling public
over long distances forming 'ribbons of service." Addi-
tional transmitters also could he located in nearby com-
munities lacking sufficient population to support their
own independent stations. Other uses could include use
of low power transmitters within a stations predicted
service area at locations suffering from inferior service
because of anomalous propagation conditions or to pro-
vide service in nulls of directional antenna patterns.
6. Although three distinct uses of multiple transmitters
were discussed in the Report, synchronous operation stim-
ulated the greatest interest, as revealed in the comments
that were filed in response to the Report. The comments
gave general support to the suggested use of multiple
transmitters for improvement or extension of AM service
areas. The commenters were encouraged by the prospect
for coverage enhancement that synchronous techniques
may offer. Other commenters to the Report recognized
the need for careful study and the value of experimenta-
tion. CBS Inc. and Association for Broadcast Engineering
Standards Inc (ABES). however, expressed concern that
such uses might increase the overall level of interference
in the AM frequency band. Although ABES agreed with
the Report's suggested methods of minimizing mutual
interference within synchronous transmitter networks, it
added that synchronous operations would offer only mar-
ginal improvement in the coverage of some stations.
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III. DISCUSSION
7. There are both technical and non-technical issues on
which data and information are needed in order to estab-
lish bases for specific rule proposals for the operation of
synchronous transmitters. Of particular importance are
issues pertaining to criteria used to define mutual inter-
ference between transmitters in a synchronized network.
Of equal importance are the interference protection cri-
teria to be applied between synchronous networks and
stations outside of the synchronous systems.
8. With respect to non-technical issues, the Commission
is of the view that restrictions on the use of synchronous
transmitters should be minimized to the extent possible.
in order to maximize opportunities for innovation and
service improvements to the public. Non-technical mat-
ters of importance include Ownership and licensing issues.
These are discussed in detail below.
Technical issues
9. Previous experiences, both in the United States and
abroad, have demonstrated that there are areas of concern
in synchronous transmitter operation. While advance-
ments in fixed point-to-point communication techniques
made since the earlier experiments will solve some of the
earlier program distribution problems. e. g.. radio or land
line signal propagation delay. a principal consideration of
synchronous operation is that of the zones of mutual-
interference. This interference occurs most prominently
in the service areas of the synchronized transmitters at
locations where the signal levels from two or more syn-
chronized transmitters are nearly equal. AM radio receiv-
ers located in these interference zones may experience
program signal fading or distortion, depending on the
method of transmitter synchronization employed. The
boundaries of these zones or areas of interference as well
as the nature of that interference are dependent upon the
system design of a group of synchronous transmitters.
10. The interference can he controlled through geo-
graphically spacing the synchronous transmitters or by
locating them in such a way as to cause the areas of
mutual interference to occur at locations where there are
few listeners. The effects of mutual interference can he
further minimized through the equalization of modula-
tion delay among transmitters.5 and through the use of
phase rather than frequency synchronization. At nighL
however, these zones of interference may be less signifi-
cant. because skywave interference received from trans-
Initters within the group or from co-channel stations
outside the synchronized group could have a gleater effect
uponservice. . ' '
Intra - system interference considerations
11. Synclzroni2aiion Techniques. Synchronization can be
achieved through either frequency synchronization or
phase synchronization. The former is accomplished by
closely aligning the carrier frequencies (to 0.1 Hz or
better), and the latter is accomplished by phase locking
the transmitters together through the use of a control
circuit. The earlier experimental operations. previously
referred to, tested both forms of synchronization. The
experiments for phase synchronization employed trans-
mitters called "boosters" or "synchronous amplifiers.
Where synchronization is only required during nighttime
hours, it may be feasible during the daytime hours for
each transmitter to broadcast separate programming. de-
pending on the transmitters' proximity to each other.
12. When phase synchronization is employed, there is
no relative carrier frequency variation between the dif-
ferent transmitters, and the pattern of mutual-interference
remains fixed in time and place. Such interference would
not be very noticable on automobile receivers since auto-
mobiles in motion would normally move quickly through
any areas of interference. For AM radios with ferrite rod
antennas (virtually all modern table models and portable
radios), the effect of the stable pattern of interference can
be greatly reduced by orienting the radio to improve the
signal strength received from one of the transmitters.
13. A difference among the carrier frequencies of the
transmitters in the group results in a variation in the total
received signal at any point in the common service area
over time. If the frequency difference is small enough (On
the order of 0.1 Hz). the variation can be compensated for
by the automatic gain control (AGC) circuitry of the
receiver and the listener will not notice significant distoi-
tion. except at locations where the signals from the dif-
ferent transmitters are nearly the same field strength. At
these latter points, the variation may exceed the dynamic
range of the AGC and distortion effects similar to slow
fading will be experienced.
14. The relative merits of these methods need to he
studied, Is there a significant advantage of one technique
over the other or should the Commission establish rules
for both? Where possible. those stations operating under
experimental authorizations with synchronous transmit-
ters are encouraged to develop data on this issue.
15. Projection rajios for synchronized !ransniiuers. The
term protection ratio" generally refers to the minimum
ratio of the field strength of a desired signal to the field
strength of an interfering signal. in order to define the
existence of interference, in the case of synchronized
network, such a ratio is applied in determining the zones
of mutual interference that occur within the synchronized
system.5 In order to facilitate establishment of an appro-
priate protection ratio for synchronous Operations. we
encourage present and prospective experimental licensees
to investigate the values of the signal-to-interference ratio
applicable to reception of transmissions from synchro-
nized transmitter groups comprised of two or more trans-
mitters, taking into account alternative frequency
tolerances. Both phase and. frequency methods of synchro-
nization should be. considered..A European study .s.ug-
gested one .ap.prach o
.r.i.ningJhe .'prptctioio.
This appioach involves the use of a statistical method
based .:.Ofl ,st,i.bjctive. inpg; imp,resso c.recpt;ion
quality, from a:transmitter.in a. synchronized. group. The
results are then compared with. reception.., quality of. a
single non-synchronized transmitter station.9 The EBU
Report cited an instance in which protection ratio values
for nonfading signals were first determined under labora-
tory conditions. For fading signals. however, only Opel'-
ational tests using a synchronized network were
conducted.
16. There are several factors to heconsidered in deter-
mining the protection ratio. These factors include: dif-
ference of transit time, frequency tolerance, whether the
interfering signals are groundwave or skywave. and the
effects of stereo and other audio processing techniques.
Thcre are also subjective factors to consider. For instance.
1390
2 FCC Rd Vol.5 Federal Communkations Commission kecord FCC 87-27
speech and some forms of contemporary music may ap-
pear less susceptible to distortion than other program
formats.
17. When three or more transmitters are used in a
synchronous network, the problem of mutual interference
is compounded. In such cases the combined effects of
miltiple interfering signals during nighttime hours must
he considered. For non-synchronized transmitters, this is
accomplished by calculating the root-sum-square (RSS) of
the interfering signals. The EBU report, referenced above.
states that in most cases where the desired signal is the
groundwave and the interfering signals are skywave. the
interference protection ratio is defined as the ratio of the
field strength of the wanted signal to the median value of
the interfering field strengths. They also suggest. however,
that the time probability of interference will lessen with
the use of several synchronous transmitters within a net-
work. We invite comments on the treatment of multiple
interfering signals within a synchronized network. Addi-
tionally. where experimentally possible. tests should be
conducted on the effects of two as compared with three or
more synchronized transmitters. Results of such tests
should be rported in the comments.
18. Transit time. Transit time is the signal propagation
time interval from the transmitter to the receivei. It is
dependent on the location of the receiver, and may vary
in the case of nighttime ionospheric propagation. if the
difference in transit time from several sources is negli-
gible and the distribution delay is equalized, theoretically
there should be no distortion, but this occurs in practice
for only a very small geographical area. Comment is
requested on the effects of transit time and the manner in
which program distribution equalization can be employed
to minimize these effects.
19. Transmiuer Power. Much of the experience from
experimental synchronized operations previously gained
within the United States employed relatively low powered
synchronized transmitters. As shown in the EBU report.
however, this is not necessarily an inherent requirement
for synchronous operation. Comments are requested as to
whether the power of synchronized transmitters should he
restricted or whether power levels up to that permitted
for the station class of the primary statioO should be
allowed, consistent with requisite protection to other sta-
tions.
Inter - system interference considerations
20. Additional important issues upon which comment
is desired concei'n the interference protection criteria that
would be applied between synchronized networks and
stations not in the synchronized network. With respect to
groundwave interference protection criteria, it appeal's
that the groundwave signal overlap restrictions specified
in Section 73.37(a) of the Rules may be appropriate. The
matter of skywave interference protection criteria, how-
ever, is not as clear. One such issue concerns the manner
in which transmitters in the synchronized network should
be protected from skywave interference caused by stations
not in the synchronized network.
21. Similarly, another issue is whether the nighttime
skywave interfering signals from the transmitters in a
synchronized network should be considered individually
or whether the cumulative interference effect of the entire
synchronous group should be considered when calculat-
ing skywave interference to other stations on the channel.
In this regard the effect of the 50% exclusion rule must
be evaluated. A decision in this area could affect the
amount of power permitted for each transmitter in a
synchronous group.
Non - technical Issues
22. Beyond the technical issues discussed above, we also
solicit comment on various non-technical policy isues
related to the use of synchronous group transmitters.
These non-technical issues can be divided into two major
categories -- (1) licensing and eligibility requirements, and
(2) ownership restrictions.
23. Licensing and EligthiUty Requirements. There are
three areas of concern regarding the substantive require-
ments and applications procedures that should be utilized
in authorizing synchronous transmitters. FirsL we request
that commenters address the question of what criteria
should he utilized in deciding whether a synchronous
transmitter should be authorized. For example, would a
synchronous transmitter be appropriate only in situations
where a conventional AM station would be precluded?
Such preclusion could occur if a proposed new AM
Station would cause prohibited overlap to other AM sta-
tions in violation of Section 73.37(a) of the Commission's
Rules or would cause nighttime interference in violation
of Section 73.182. Additionally. would the mere desire of
a licensee to increase coverage in one or more directions
be sufficient justification to permit synchronous opera-
tion?
24. Although synchronous transmitters may be used to
enhance or extend the coverage areas of AM stations,
should there be any limits ihposed on the extent to
which the coverage area of an AM station may be aug-
mented by the use of synchronous transmitters. and if so,
what should they be? Alternatively, should synchronous
operation be permitted only within an AM station's pro-
tected contour under the Commission's Rules? We solicit
comments on these questions and other matters related
thereto.
25. Second, we invite comment on who may be licensed
to operate synchronous transmitters. Because these trans-
mitters may cause interference to the signal of the pi'i-
mary AM station that is being rebroadcast or to other
synchronous transmitters within the same network, we
are not inclined to authorize their use by any party other
than the AM station licensee who seeks to expand its
service area. Moreover, such a licensing limitation is
consistent .with the requirement that FM boosters--which
rebroadcast the programing of a parent FM station on the
same carrier frequency as the parent station-he autho-
rized only to the licensee or permittee of the parent
station)0 Since synchronous transmitters, like FM boost-
ers. operate on the same frequency as the parent station
and pose a potential for interference to the primary
station. we believe that a similar licensing limitation
would be appropriate.
2o. Third, we question how requests or applications for
synchronous transmitters should be processed. Our initial
view is that such applications should be processed like
applications for major or minor changes in AM broadcast
facilities because synchronous transmitters are intended to
be permanent and protected improvements to the cov-
erage of existing AM stations. Consequently. if an applica-
tion for a synchronous transmitter is processed like a
major change, it would be placed on a cut-off list and
could not be acted upon by the Commission until after a
30-day public notice period. During that time. the public
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FCC 87-27 Federal Communications Commission Record 2 FCC Red Vol.5
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would be afforded an opportunity to file petitions to deny
pursuant to Section 309(d) of the Communications Act
and Section 73.3584 of the Commission's Rules. In addi-
tion. any applications for changes in existing AM facilities
or for new AM stations which may be mutually exclusive
with a synchronous transmitter proposal would have to be
filed during this 30-day period)' Such mutually exclusive
applications generaib,' warrant a comparative hearing to
select a permittee under the As/ibacker doctrine:12 I-low-
ever, if a request for a synchronous transmitter were
processed like a minor change in facilities, it could be
gianLed without the necessity of being placed on a cut-off
list: and only those informal objections filed prior to
grant could he considered. Accordingly. we request com-
ment on whether such a cut-off list approach should he
utilized or under what circumstances requests for syn-
chronous transmitters should he considered as minor
changes. Alternatively, we question whether synchronous
transmitters should he treated as secondary to full-service
stations and be afforded no continuing protection.
27. Ownership Restrictions. Next, we must consider
whether owneiship restrictions should apply to synchro-
nous group transmitters on either a local or a national
basis. Such restrictions currently apply to the commercial
AM. FM. and television services. With respect to national
ownership restrictions, the Commission generally permits
an individual to have a cognizable ownership interest in
a maximum of 12 commercial AM stations.' The ques-
tion arises as to whether synchronous transmitters, addi-
tional to the primary station, should he counted for
purposes of this 'rule of 12.' Our preliminary view is
that synchrohobs transmitters shouki not he attributed
under this rule. We base this position on two reasons.
First, we believe that such a restriction may not allow for
the full development of this proposed new broadcast
technique and the benefits that it may afford. If broad-
casters are limited to owning a total of 12 commercial
AM stations, including synchronous transmitters, then
they might he discouraged from building many synchro-
nous transmitters because it could affect the number of
additional AM stations that they could acquire. Second.
exempting synchronous transmitters from the national
ownership restrictions would be consistent with Commis-
sion precedent. in this regard. the Commission does not
count terrestrial satellite television stations for purposes of
the twelve-station i'Wc. Like synchronous transmitters.
these satellite television stations repeat most, if not all, the
pràgramming from a parent station'and can have broad-
cast facilitie comparable in power and coverage to the
paient station Accoidingl we solicit comment on
whether:we should take .the same approach for synchro-•
flOU5:trnSrflittClS; ..::::. . ....,. .,
28. W also jf to cOnside whéthëf JodalO*nership
i'eti'ictions should apply to synchronous group transmit-
ters. One such restriction is the AM 'duopoiy" rule
which currently prohibits overlap between the I mV/rn
contours of commonly owned commercial AM stations.'5
Clearly. the 'duopoly" rule should not apply to overlap
occuring within a synchronous network. Such local own-
ership restrictions would have the detrimental effect of
unnecessarily inhibiting the development of this new
technology and preventing the enhancement or expansion
of service by AM broadcasters. For similar reasons. we
also believe the "duopoly" rule should not prohibit in-
stances of contour overlap between synchronize transmit-
ters and other comrnonl owned AM stations that are not
part of the same synchronous network.
2. Another local ownership restriction is the
'one-to-a-market" rule which, inter alia, prohibits the
common ownership of commerciaL AM and television
stations in the same market. Specifically, the rule achieves
this result by barring cross-ownership whei'e either the 2
mV/rn groundwave contour of the AM station encom-
passes the entire community of license of the television
station, or where the predicted Grade A contour of the
television station encompasses the entire community of
license of the AM station." We bel'reve that it would he
inappropriate to apply this cross-ownership restriction, to
synchronous transmitters as this would also hamper the
development of this technology. Moreover, exempting
synchronous transmitters from this rule would give AM
broadcasters greater flexibility in using this technology to
enhance and expand their service areas since they would
not have to he concerned with contour encompassment
between ,commonly owned television stations anti AM
synchronous transmitters. Accordingly. we solicit com-
ment on whether the public interes) would be served by
exempting synchronous transmitters from the "duopoly'
and 'oneto-a-ma,'ket" rules.
IV. CONcLUSION
30. Synchronous transmitter systems have been success-
fully used in Europe for many years to extend service.
Although conditions in the United States differ, such
operations appear to offer advantages here as well. Inter-
nationally. general standards fo,' synchronous transmitter
systems already exist, hut standards specifically tailored
for the U.S. need to be developed. Moreover, non-
technical issues unique to the U.S. need to he resolved
before synchronized networks can he routinely autho-
rized.
31. The primary issues addressed in this Inquir,v are
summarized as follows:
What technical standards should be adopted govern-
ing the operation of a synchronous group of trans-
mitters as it affects intra-system interference and
other system impairments.
What interference protection criteria should be ap-
plied between synchronous networks and individual
stations not in the synchronous network
What level of distortion can be anticipated as a
result of using frequenço phase synchronization
techniques and which synchronization technique is
more adyantageous? .
Would the utility of nighttime synchronous trans-
mitter operations be diminished significantly be-
cause of skywave interference?
What treatment should synchronous transmitters be
afforded under the multiple ownership rules and
what licensing criteria should be applied?
32. In order to assemble a comprehensive record, we
invite comment from all interested parties on the issues
discussed in this Inquiry. We also encourage experimental
licensees to submit their results or observations relating to
the technological concerns raised in this Inquiry. If corn-
1392
2 FCC Red Vol. Federal Communications Commission Record FCC 87-27
menters wish to address issues we have not identified, we
encourage them to do so. The record established in this
proceeding will allow the Commission to analyze the
impact of synchronous group transmitters on the delivery
of AM service to the general public, and to develop rule
proposals.
33. Pursuant to applicable procedures set forth in Sec-
tions 1.415, and 1.419 of the Commission's Rules, inter-
ested parties may file comments on or before May 4, 1987
and reply comments on or before June 3, 1987. All
relevant and timely comments will be considered by the
Commission before final action is taken in this proceed-
ing. To file formally in this proceeding participants must
file an original and five copies of all comments, reply
comments and supporting comments. If participants want
each Commissioner to receive a personal copy of their
comments. an original and nine copies must be filed.
Comments and reply comments should be sent to Office
of the Secretary, Federal Communications Commission.
Washington. D.C. 20554. Comments and reply comments
will be available for public inspection during regular
business hours in the Dockets Reference Room (Rm. 239)
of the Federal Communications Commission. 1919 M
Street. N.W., Washington. D.C. 20554.
V. AUTHORITY
34. Authority for issuance of this Notice is contained in
Sections 4(i). 303(r) and 403 of the communications Act
of 1934. as amended.
35. For information concerning this proceeding contact
Bernard Gorden at (202) 632-9660 or Andrew 3. Rhodes
(Legal) at (202) 632-7792.
FEDERAL COMMUNICATIONS COMMISSION
William .1. Tricarico
Secretary
FOOTNOTES
The Report (pp. 71-77) included a discussion on the follow-
ing three types of multiple transmitters: (1) synchronous opera-
tion, (2) AM satellite stations, and (3) AM/FM translators.
2 Since January 1986, the Commission has granted
experimental authorizations for the construction of synchro-
nous systems to the following licensees: I(ROL of Henderson.
Nevada; KOB of Albuquerque. New Mexico; KIPA of Hilo.
Hawaii; and WiNO of West Palm Beach. Florida. Requests for
experimental authorizations for synchronous transmilter oper-
ations are currently pending from the following stations:
KGNW of Seattle, Washington; KNEW of Oakland. California:
KNIJZ of Houston, Texas; and WORC of Worcester. Massachu-
setts. Experimental authorizations are on a secondary basis and
are not afforded interference protection from other existing or
future primary station assignments. Such authorizations also
require that the permittees file comments to this Inquiry and
detailed progress reports on their experimental operations.
Sec Bell Telephone System technical publication. A Study
Of Reception From Synchronized Broadcast Stations.t by
Charles B. Aiken. Bell Telephone Laboratorie5. published in
Proceedings of the Institute of Radio Engineers, Vol. 21, pp.
1265-1301, September. 1933.
' See European Broadcasting Union (EBU) Technical Report
3210, August 1974. 'Synchronizei1 Groups of Transmitters in
LF and MF Broadcasting." which includes examples of low to
high powered synchronous transmitters and techniques of fre-
quency control. etc.
Modulation delay, in thi5 case, is the amount of time that
the program signal is delayed in being processed onto the
carrier frequency.
The control could be accomplished in any of several ways.
including for example. the use of digital techniques employed
via a microwave radio link.
See the British Broadcasting Corporation. Research Depart-
ment Report. February 1976, "Reduction of mush-area distor-
tion in common-frequency M.F. transmitter networks."
The current international protection ratio for synchronous
operation used in international Agreements applicable to the
U.S. is 8 dB. See Final ActS of the Regional Administrative MF
Broadcasting Conference (Region 2). 1981 and Agreements be-
tween the U.S. and Canada. and Mexico. respectively signed in
1984 and 1980.
' See CCIR Document Recommendation 500-I listing EBU
reports on synchronized transmitter networks from the United
Kingdom. India, and Japan.
It) Sec 47 C.F.R. Section 74.1232(e) (1985).
A mutually exclusive situation arises whenever two or
more bona fide applicants timely file for use of the same
broadcast frequency. or for different frequencies whose use
would be technically incompatible under the Commissions
Rules.
12 See Ashbacker Radio Corp. v. FCC. 326 U.S. 327. 333
(1945).
13 An individual generally has an attributable interest in a
broadcast station if the individual is an officer, director, general
partner, or owner of 5% or more of the voting stock of the
station. See 47 C.F.R. Section 73.3555. Notes I and 2 (1985).
' Sec 47 C.F.R. Section 73.3555(d)(L) (1985). This limit may
be increased to 14 AM stations provided that the additional two
stations are controlled 50% or more by members of minority
groups as set forth in 47 C.F.R. Section 73.3555(d)(3) (1985).
' 47 C.FR. Section 73.3555(a)(1) (1985). We recently pro-
posed to relax the radio 'duopoly" rule. See Notice of Proposed
Rule Making in MM Dockei No. 87-7. FCC 87-28. adopted
January 15, 1987.
47 C.F.R. Section 73.3555(b)(I) (1985). In MM Docket No.
87-7, we have also proposed to modify the scope of the radio-
television cross-ownership provisions of the 'one-to-a-market'
rule. See note 15, supra.
I