NASB  Newsletter
April 1999

NATIONAL ASSOCIATION OF SHORTWAVE BROADCASTERS, Inc.
10400 NW 240th Street, Okeechobee, Florida 34972

Ph:  (941) 763-0281               Fax: (941) 763-1034 or 8867               E-mail:  nasbmem@rocketmail.com


 
Letter From the President:
 

THE NASB IN THE PAST TEN MONTHS

NASB NEWSLETTERS:  Four in 10 months, thanks to several NASB Board
members.  We didn't have 4 as a goal and may not do that many in
the next 10 months. Hope you have enjoyed them. If you haven't seen
them all, please let us know and we'll see that you get a printed
copy.  Our news letters are available on the Web, by Email or in
printed form.  Future Newsletters will be sent via Email.  If you
are not on our address list, and would like to be, please contact
Dan Elyea: fsiyfr@okeechobee.com

NASB WEB SITE: NASB has a Web Site at www.shortwave.org which
contains information on the NASB as well as the NASB Newsletters.
Please check it out at your convenience.

DIGITAL SHORTWAVE: Where is it going and how have we been involved?
The NASB is now an Associate Member of the DRM, Digital Radio
Mondiale. Special thanks go to the four organizations who were our
sponsors: Continental, TCI, Harris and Nozema of the Netherlands.
The DRM is an international organization whose purpose is to see
that digital broadcasting has predetermined standards so that the
world does not end up with non-compatible systems, such as happened
with stereo AM.  The NASB was represented at DRM meetings on March
11-12 and will be represented at the April 16-18 meetings in Las
Vegas.  Our position as private non-governmental shortwave
broadcasters is for some type of IBOC system where both analogue
and digital can be transmitted simultaneously during the transition
period while digital is gaining acceptance. (Please see the article
in this NASB issue.) At the moment it appears that an IBOC type
system would require more bandwidth than is presently available,
but we still wanted to make our needs and desires known in the
places where the decisions will be made, such as the DRM.

USWG-10A:  What is the USWG-10A?  It is a national committee that
makes recommendations to the U.S. government on what positions
should be taken at WRC Conferences on matters related to shortwave.

The NASB is represented and has an active voice on this committee.
Walt Ireland, chairman of the USWG-10A committee, will be reporting
at the NASB Annual Meeting on May 7 in Washington, D.C.

NASB BOARD MEETINGS VIA EMAIL:  In the past, meetings of the Board
were held via telephone conference calls.  This was expensive and
it was often difficult to find a time when all Board members were
available.  This past year all Board meetings have been by Email.
This is easier, can be done more often and at less expense and
leaves a "paper trail" of everything said and actions taken.

Thank you for your participation in the NASB. We always welcome any
suggestions you may have that will help make us more effective.

Cordially yours,

William "Ted" Haney
President, NASB
 

Subject to some possible changes, below is the agenda for the 1999
NASB  Annual Meeting:
 

NATIONAL ASSOCIATION OF SHORTWAVE BROADCASTERS
               9th ANNUAL MEETING
 
                       FRIDAY, MAY 7, 1999
                     Holiday Inn Crystal City
                   2799 Jefferson Davis Highway
                   [Crystal City stop on Metro]

8:15AM   COFFEE & REGISTRATION              Sponsored by:
                                            CONTINENTAL ELECTRONICS

8:45AM   Welcome                                             Ted Haney, NASB President
 
8:50AM   Report for the FCC                             Tom Polzin, FCC
 
9:00AM   Report on IBOC Modulation System   USADR
 
9:30AM   DRM - Digital Radio Mondiale             Dr. Don Messer, VOA/IBB
                World Consortium for Digital
                Broadcasting

9:40AM   Report on USWG-10A Committee      Walt Ireland, ARRL Chairman, USWG-10A

10:00AM  Coffee Break                                       Sponsor: TECHNOLOGY for
                                                                            COMMUNICATIONS, INTL.

10:30AM  Automation of Transmitter and             Adil Mina, CONTINENTAL
                 Antenna Systems

11:00AM  Digital Audio System for Program        Ken Tankel, DALET
                 Automation

11:45AM  Panel by shortwave users                     Ed Evans, WSHB
                 of the Dalet System                              Frank Leurck
                                                                             and/or
                                                                             Joe Dentici, WEWN
                                                                             Ken Tankel, Dalet

12:15PM  Luncheon                                             Sponsored by: THOMCAST
 

1:45PM   NASB Business Meeting
 

3:45PM   NASB Business Meeting Adjourns
 

NASB  RECOMMENDATIONS REGARDING THE RE-ALIGNMENT OF THE 7 MHZ BANDS
AND AVAILABILITY OF FREQUENCIES FROM  4-10 MHZ

Allocations:
            Amateur band       7.0 - 7.3   MHz (worldwide)
            Shortwave band     7.1 - 7.35  MHz (Regions 1 & 3)

The private broadcasting sector would prefer separation of the
amateur and international shortwave broadcasting services so they
do not overlap.

One solution would be for the amateur band to encompass  6.8  to
7.1  MHz and international shortwave occupy  7.1  to  7.35 MHz.

There may be some conflict with fixed users in the  6.8  to  7.0
MHz band.  One possibility would be for some sharing of frequencies
on a non-interference basis.  Some U.S. broadcasters are using up
to  7.5  MHz on a non-interference basis with little problems.

Additional frequencies are needed between  4.5  and  9.9 MHz.  They
could be used by broadcasters on a shared or non-interference
basis.

It is felt that any frequencies  shared on a non-interference basis
should not be limited to  SSB or digital transmissions, but should
include  DSB.

A concern has been raised about broadcasters using high powered
transmissions on frequencies in the 60 meter band.  Many countries
assign these frequencies on a more or less permanent basis to
stations broadcasting within a country or region.  These stations
are often limited to  5-10 kw in power and are not free to move to
another frequency if some other station is interfering with them.
 

NASB RECOMMENDATIONS REGARDING DIGITAL BROADCASTING FOR SHORTWAVE

NASB would favor an IBOC type system for the following reasons:

An  IBOC type system would allow analogue and digital to be
broadcast at the same time.  This would make it possible for most
all of the private sector broadcasters to participate in digital
transmissions during the transition period.  This would not only
include the private sector broadcasters in the U.S. but also the
vast majority of smaller broadcasters worldwide.

A non-IBOC system requiring separate transmitters for digital would
prevent most  private sector broadcasters from participating in
digital broadcasts due to a lack of transmitters.  Often large
government broadcasters, who have a number of transmitters, are
able to use one unit for digital broadcasts.

Broadcasters associated with the NASB transmit over 900 broadcast
hours/day in more than 160 languages with a combined transmitter
power in excess of 7 megawatts.  They believe that their ability to
participate in digital broadcasts would contribute to the
popularization of digital shortwave and shorten the transition
period from analogue to digital.

Any system, requiring a separate transmitter and frequency for
digital transmissions, could lead to additional crowding in the
currently available shortwave bands.
 

DIGITAL  HF  BROADCASTING -- THE WAVE OF THE FUTURE?

One of the hottest topics in the international broadcasting
community these days is the possibility of digital shortwave
broadcasting, and whether this will "save" shortwave as a broadcast
medium in the 21st century.  Educated people and technical experts
don't always agree on all aspects of this subject. Some believe
digital is the only thing that can save shortwave from a certain
death as we enter the new millennium; others think it will be a
complete flop.  Still others think that digital shortwave has a
future, provided certain other things happen concurrently.

In the following section, we present summaries of several lectures
dealing with aspects of digital shortwave radio that were presented
at the 1998 annual meeting of the NASB.
 

WRC 97 AND HOW IT WILL AFFECT SHORTWAVE BROADCASTERS
Dr. Don Messer of the U.S. International Broadcasting Board

Dr. Don Messer was the sole delegate from the United States dealing
with items related to shortwave broadcasting at the 1997 World
Radiocommunications Conference (WRC 97), a specialized meeting of
the International Telecommunication Union (ITU).  Three main
shortwave-related topics were discussed:

1.  Seasonal Planning Procedures -- The ITU Radio Regulations were
modified, eliminating references to the centralized frequency
planning process of the ITU Radiocommunications Bureau, and
replacing them with references to the activities of the High
Frequency Coordinating Committee (HFCC).  Regional planning
committees now do most of the seasonal frequency coordination, with
only a few final touches provided by the ITU Radiocommunications
Bureau.

2.  Digital Shortwave Broadcasting -- Nearly all national
administrations supported the use of digital modulation for
shortwave broadcasting.  It is clear to most people that the ITU's
previous efforts to promote single sideband (SSB) shortwave
broadcasting are effectively dead, since SSB "will never take hold
as a mass-media transmission method for shortwave broadcasting."
The momentum now is behind digital shortwave broadcasting, and
there was a lot of discussion about the likelihood of a mass
conversion of shortwave to digital modulation.

3.  WARC-92 Allocations to Shortwave Broadcasting -- At the 1992
World Administrative Radio Conference, an additional 790 kHz was
added to the shortwave broadcasting spectrum, but it was decided
that these frequencies could not be used officially until 2007, and
then only in the SSB mode.  As a practical matter, there is already
extensive use of these new frequencies by stations around the world
on a non-interference basis.  During the year ending November 1997,
the ITU received only one interference complaint resulting from the
use of these WARC-92 sub-bands.  Nevertheless, the proposal to make
them official before 2007 was defeated, largely because of protests
by fixed and mobile service users in developing countries.

The next WRC will be in 2001, and another attempt will be made to
officialize the WARC-92 frequencies there.  In terms of the
shortwave agenda, the 2001 meeting will also deal with realignment
of service allocations around 7 MHz to achieve worldwide
consistency, and an examination of the adequacy of shortwave
frequency allocations between approximately 4 and 10 MHz.
 

IBB/JPL DIGITAL MODULATION SYSTEM FOR SHORTWAVE
Presentation by Dr. Don Messer of the U.S. IBB

The U.S. International Broadcasting Bureau and the Jet Propulsion
Laboratory have jointly developed a digital system which was tested
in September of 1997.  Transmission took place in California at a
power of 12 kilowatts in both AM and digital modes on HF
frequencies.  Reception took place in Washington, DC -- a distance
of about 4000 kilometers (2500 miles).  Dr. Messer played a tape
which was recorded in Washington with samples of both the digital
and AM broadcasts.  Reception of the digital mode, even when
propagation was poor, showed much less noise and fading than did
the AM mode.

The system operates within a  10 kHz bandwidth of HF spectrum.
About 20% of the transmitted bit-stream is used to enable adaptive
equalization in the receiver.  This reduces muting of the digital
transmission resulting from multipath reception.  In digital
transmission systems, when the signal-to-noise ratio becomes too
small, the signal must be muted, or else gibberish results.  The
IBB/JPL approach uses time interleaving techniques involving some
scrambling of the audio modulating signal.  This minimizes the
effects of noise bursts or sudden propagation changes on the
reception quality.  Also, forward error correction is used to
reduce deterioration of the received audio by the effects of the
transmission path such as fading and interference.

One goal in implementing digital modulation is to develop
techniques that will work with most existing transmitters with
little or no notification.   Another goal is to accomplish digital
modes within the same occupied bandwidth as used by present direct
satellite broadcasting systems of modulation.  It is also desirable
to develop a system that can be used with high-power, non-linear
operation.

As a result of the tests thus far by IBB/JPL, Dr. Messer concludes
that it should be possible to develop a commercial product for HF
digital service.   This system will receive audio with quality
equal to or better than unimpaired analog  DSB.  The digital
approach will experience considerably less deterioration due to
fading, noise, and interference over long-distance skywave paths.
Many, if not most existing transmitters can be used with little or
no modification, and under the same parameters as a given  DSB
system, digital can achieve the same coverage using much less
power.

Note:  This system has been dropped out of consideration by the DRM
because IBB/JPL felt they had not developed it far enough for it to
be included with the German and French systems.

UPDATE ON DIGITAL BROADCASTING FOR SHORTWAVE
By Dr. Robert Everett of the U.S. International Broadcasting Board
 
Dr. Everett of the IBB reviewed the existing major approaches to
digital  AM  broadcasting.  Being loaded with technical details,
these do not lend themselves very well to brief summaries.

One pertinent point he made relates to the "transition period"----
the period spanning the introduction of digital transmission to the
time when broadcasting has gone fully (or almost fully) digital.
He sees it as likely taking  20-25 years.  During this transition
period, it will be necessary to simultaneously transmit in both
analog and digital modes.  Thus both the previously existing and
the new digital receivers can make use of the transmission.

Summary of advantages of digital modulation as compared to analog
modulation:  superior area of coverage;  superior audio quality;
superior immunity to interference;  requires about  10 db less
transmitter power for same area of coverage;  capability of two
programs going out at the same time on a single channel;  will
transmit multi-media;  though not an "advantage", the fact that it
will  adapt well to modern transmitters is a favorable factor.

The Thomcast system requires a very linear response from the
transmitter for practical implementation.  It does provide for
simultaneous analog and digital transmission as needed during the
transition period.

Tests in Berlin by Deutsche Telekom/Telefunken/Continental indicate
that by using digital modulation, mediumwave stations can achieve
the same coverage at night as in daytime hours, something certainly
not possible with analog modulation techniques.  Because of the
narrow-band characteristics of longwave and mediumwave antennas,
phase-correction feedback techniques via sampling from the
transmitted signal must be implemented at the transmitter site so
the received signal will not be scrambled by phase error.

Note: In the March 11-12 DRM meeting in Geneva, it was decided that
the German and French developers of these two different modulation
systems should work together.  There was no decision to favor one
system over the other.  They are to work together to come up with
the best system possible.
 

WORLD CONSORTIUM FOR DIGITAL AM BROADCASTING, LW, MW and SW
By Dr. Robert Everett

Digital Radio Mondiale (DRM) is a consortium for creating a system
that will become a single world standard for digital  AM
broadcasting.  Members of the DRM include national broadcasters,
international broadcasters, broadcasting unions, network service
providers, receiver and transmitter manufacturers, standards
organizations, research organizations, and regulatory
organizations.  Inaugurated in March of 1998, the  DRM  consists
presently of 26 members.

The  DRM functions in partnership with the  ITU.  Organizationally,
the  DRM consists of the General Assembly (the assembly of all
members), the  Steering Board (creates policy), the Commercial
Committee (does all commercial work such as priorities, PR,
determining functional requirements, etcetera), and the Technical
Committee (develops the technology for a practical working digital
system).  A Project Office (takes care of the business of the
organization) is in the formative stage.

Dr. Everett enumerates these advantages of membership in  DRM:  the
honor of stimulating digital  SW development;  participation in
overall  DRM guidance;  access to privy information relating to
system designs for transmitters and receivers;  increase of
intellectual property via technical participation in  DRM.

DRM  will attempt to meet a deadline of  October 1999  to have a
standard specified for digital broadcasting, and testing of that
standard underway.

On the Web, you can find  DRM  information at  www.drm.org
 

SURVEY OF DBS IMPLEMENTATION
By  Dr. Don Messer

Dr. Messer briefly reviewed direct satellite broadcasting in the L
(around 1.5 GHz) and S (around 2-3 GHz) bands allocated in WARC-92.
This concerned satellite radio broadcasting direct to portable
receivers, fixed dishes, or into vehicles.  Several systems are
relatively close to implementation.  Predictions indicate that some
systems could be operating within 2 to 3 years from now in the USA.

Approximately  30  CD-quality channels will be available with
coverage over the entire USA.

Time of implementation in other countries cannot be predicted as
readily.  Since the reception is basically line-of-sight, blockage
by buildings and trees presents a major reception problem for
unassisted satellite delivery when using mobile or indoor antennas.

Regulatory problems related to "spill-over" coverage by a satellite
broadcast also pose a difficult obstacle in the path of
implementation of  DBS.

Dr. Messer does not see DBS as a serious threat to shortwave
broadcasting, provided that shortwave broadcasting can be improved
over the years by converting to a digital mode of modulation.
 

1999-GREAT YEAR FOR  HF  BROADCASTING
By George Jacobs

Solar activity, upon which the propagation and reception of high
frequency (HF) or shortwave broadcasters depend, is expected to
reach peak intensity during 1999, at a level much higher than has
been observed during the past ten years.

The present 11-year cycle of sunspots is the 23rd since daily
telescopic observations of the sun began late during the 18th
century.  Sunspots are a measure of solar activity.  Cycle 23 began
during 1996, rose slowly during 1997, and increased considerably
during 1998.  It is  expected to rise to peak intensity---likely to
exceed a count of 155--- by the end of 1999.  This would be the
highest level of solar activity to occur since 1989.

This is good news for broadcast listeners on the HF bands, since it
portends exceptionally good reception conditions during the
remainder of 1999.  The greater number of sunspots, the stronger is
the ionosphere, that electrified region in the earth's upper
atmosphere which reflects HF radio waves over great distances.

Improved reception conditions are also expected during 1999 as a
result of the continuing success of the High Frequency Coordinating
Committee (HFCC).  This international organization, comprised of
approximately 50 HF  broadcasting organizations, is responsible for
coordinating more than 70% of the frequencies used by the world's
shortwave broadcasting stations.  This means less interference
between cooperating stations, and clearer reception.

The combination of increased solar activity and the continued
success of the  HFCC  should result in stronger, clearer reception
on the  HF  bands during the rest of 1999.

NASB Members:
Adventist World Radio
Family Radio Network
Far East Broadcasting Co.
Herald Broadcasting Syndicate
High Adventure Ministries
LeSea Broadcasting Corp.
Radio Miami International
TransWorld Radio
WorldWide Catholic Radio
 

NASB Associate Members:
Antenna Products
Continental Electronics Corp.
George Jacobs & Associates
HCJB World Radio
IBB
Technology for Communication Int'l.
THOMCAST, Inc.
 
 

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