IN THIS ISSUE:
NASB Participates in HFCC Conference in Bonn
Reports From the 2002 NASB Annual Meeting:
Radio Frequency Safety for Shortwave Broadcasters
Digital Radio Mondiale Today
AWR Shortwave Equipment for Sale
NASB Participates in HFCC Conference in Bonn
Jeff White---Radio Miami International
The Gaestehaus Petersberg, a stately mansion atop a hill overlooking the scenic Rhine River just south of Bonn, Germany, was the site of the A02 High Frequency Coordination Conference (HFCC) February 4-8, 2002, sponsored by Deutsche Telekom. The Petersburg is an official guest house of the government of Germany for visiting foreign dignitaries, and also serves as a commercial hotel. Past guests have included the likes of Leonid Brezhnev, Bill Clinton and in December of 2001, the delegates to the United Nations Conference on Afghanistan, where Hamid Karzai was chosen as the interim leader of the country. So it was appropriate that this international guest house was the venue for the semi-annual HFCC-ASBU Conference, where shortwave frequency planners from around the world gathered. ("ASBU" indicates that it was a joint meeting with the Arab States Broadcasting Union.)
In fact, this HFCC Conference had a record number of participants -- something like 135. Approximately 80% of the world’s shortwave frequency usage is planned at the HFCC, in this case for the period from March 31-October 26, 2002. This was my second opportunity to represent the NASB at the HFCC Conference, the first time having been in Montreal in August of 2001. Twice each year, for four-and-a-half days, the world’s HF frequency planners get together at the HFCC Conference to plan their frequencies and negotiate deals to avoid interference and chaos on the shortwave bands. This time, the task was even more monumental since the terrorist acts of Sept. 11th had sparked a sudden increase of approximately 25% in shortwave transmissions (particularly to Afghanistan and the southwest Asian region), and a corresponding increase in frequency usage. Each day of the conference, new lists were produced -- hundreds of pages long -- of station broadcast schedules and "collision lists," the latter of which show co- and adjacent-channel frequency usage by two or more stations at the same time to the same target areas which could result in mutual interference. In addition to many hours of hovering over laptop computers and conversing with frequency managers of other stations, there were some interesting seminars presented at the HFCC Conference. For example, Norbert Schall of Deutsche Welle spoke about a relatively low-cost remote monitoring system he has developed, and Merlin Communications presented a prototype receiver to pick up DRM digital shortwave transmissions.
The five-star Hotel Petersberg was nestled in the woods in a rather isolated location that was conducive to the business at hand. But a short taxi or shuttle bus ride took delegates to the nearby town of Konigswinter, where many conference participants in fact stayed in alternate hotels, and where many others went for dinner at picturesque small restaurants along the Rhine River which served excellent local and international cuisine at very reasonable prices. On the Wednesday night of the conference, host Deutsche Telekom took the entire delegation by bus to the beautiful city of Cologne, a half hour away, for a lavish buffet and musical entertainment in a typical German beer hall just a few steps away from the famous Cologne Cathedral, drenched in green floodlights that amplified its majesty against the cold night sky.
In addition to myself, NASB member station WEWN sent Terry Borders and Dennis Dempsey to observe the frequency coordination process. Their frequency manager, Stanley Leinwoll, normally attends the HFCC conferences, but was unable to attend this time. Also NASB member station KTWR had a representative, Jeff Lecureux, who was very active in the coordination activities for his own station. The Adventist World Radio and Far East Broadcasting delegations looked out for their stations on U.S. territory as well as their overseas stations. George McClintock of WWCR in Tennessee also attended the conference. In his opening remarks, HFCC Chairman Oldrich Cip thanked the NASB for its continuing assistance in gathering frequency requirement data from some of the major Latin American shortwave stations. Tom Polzin and Tom Lucey of the FCC’s International Bureau were on the scene in Bonn. This was the first time the FCC has sent two delegates to an HFCC conference, and the Commission will likely only send one delegate to future conferences. HFCC Chairman Oldrich Cip asked Tom Polzin and myself to meet with him to discuss the NASB’s future participation in the HFCC and its conferences. I explained that while we find it very beneficial to attend these conferences, financial realities may prevent us from attending some meetings due to their distance and costs. (For example, the next two meetings will be in Bangkok and South Africa.) For this reason and others, I explained that we prefer to remain a part of the FCC delegation, rather than seek separate membership status in the HFCC. Tom Polzin said that he welcomes the NASB’s participation in the FCC delegation to assist him since we have more detailed knowledge of the individual member stations and their technical characteristics and needs. Also, Tom pointed out that the FCC’s budget is very changeable, and at any moment it could decide not to send any more delegates to the HFCC conferences. Therefore, he thinks it is very prudent for the FCC-licensed stations to familiarize themselves with the frequency coordination process and make contacts, so that they could take over their own frequency coordination at a moment’s notice if this were to become necessary at any point in the future. As a result of our meeting, Oldrich Cip agreed to approach the HFCC Steering Board about the possibility of granting pass codes to the frequency managers of all FCC-licensed shortwave stations which would give them access to the private area of the HFCC website where tentative frequency requirements are posted approximately three weeks prior to each seasonal meeting. This would permit stations to identify potential collisions and come up with possible solutions even before the HFCC conferences, thus making everyone’s jobs a little easier. The Steering Board later approved this measure, and it is hoped the new system can be implemented very soon.
Our presence in Bonn enabled us to solve several scheduling problems involving the privately-owned U.S. shortwave stations. For example, we were able to notify Doug Garlinger of LeSEA Broadcasting about a potential collision involving KWHR, which fortunately did not seem to be a problem. Doug e-mailed us a list of schedule changes that he had originally submitted in December, but for some reason did not appear in the updated HFCC list. We gave these to Tom Polzin, who got them into a revised list. However, Tom noticed a problem with a change of azimuth from Africa to Europe, which produced a co-channel collision with Radio Portugal. I e-mailed Doug to see if he preferred to look for an alternate frequency for that transmission, or if he preferred to leave the azimuth toward Africa and thus avoid the collision. He chose the latter course, and a collision was avoided. We were also able to notify member stations WTJC and KNLS about collisions indicated on the HFCC lists. Hans Johnson, the frequency manager of WINB -- a non-member of NASB at that time -- had submitted their A02 schedule to us before the conference, and I found that their new requirements were not on the HFCC list. Again, the correct requirements were given to Tom Polzin, and the next day they were in the updated HFCC list. However, careful checking revealed four WINB listings with incorrect start and stop dates, plus an extraneous listing that would have made it appear that WINB was listing "wooden transmitters." These errors were pointed out to Tom, and they were duly corrected in the following day’s update. As a result of the assistance we provided WINB, Hans Johnson indicated that the station had decided to become a member of NASB.
For frequency planning purposes, Tom Polzin of the FCC’s International Bureau explained that the use of out-of-band frequencies by FCC licensees has to be approved by an interagency governmental body. He provided us with a list of pre-approved out-of-band frequencies which we were authorized to make available to legitimate frequency managers of any NASB member station. This list will save a lot of time and possible frustration for our members.
Both Adventist World Radio and independent frequency manager Bernd Friedewald approached us in Bonn to offer surplus transmitting equipment to members of NASB who might be looking for shortwave transmitters, antennas, etc. I asked them to submit the details to us by e-mail for inclusion in the NASB Newsletter. We were also approached by Walter Brodowsky of Deutsche Telekom regarding an agreement to broker airtime on their large shortwave station in Julich, Germany. Deutsche Telekom will be preparing a draft agreement for NASB’s review. Even if NASB as an entity decides not to pursue this type of commercial activity, some of our member stations may find it an attractive opportunity.
Thursday, February 7, was a local festival in the Cologne area called
Weiberfastnacht (the day before Carnival). According to tradition,
women take over the local government at 11 minutes past 11 a.m., and they
are authorized to literally cut the ties off of any man who dares to wear
this item of apparel on this day. In keeping with the tradition,
HFCC Chairman Oldrich Cip was temporarily deposed at 11:11 a.m. and replaced
by Teresa Beatriz Abreu of Radio Portugal, who skillfully wielded a pair
of scissors and cut off Oldrich’s tie and those of a few others who did
not heed the warning.
At the end of the day, Teresa was thanked for her leadership and Oldrich was replaced as Chairman, just in time for the Plenary Session of the Conference. It was announced that the next HFCC Conference will be August 26-30, 2002 in Bangkok, Thailand, sponsored by Merlin Communications. July 19, 2002 is the deadline for submission of tentative requirements for the B02 broadcast season. HFCC delegates accepted the invitation of Rodgers Gamuti of Sentech to sponsor the February 2003 HFCC Conference in Sandton (near Johannesburg), South Africa. Independent frequency manager Ludo Maes of the well-known Transmitter Documentation Project (TDP) in Belgium was admitted as the newest member of the HFCC with a round of applause. And brief reports were presented by the heads of HFCC committees dealing with propagation and coordination software, a survey of antenna designs used by members worldwide, a monitoring group which will verify whether stations are actually on the air according to their coordinated schedules, and shortwave-related issues to be discussed at the 2003 World Administrative Radio Conference. Jan-Willem Drexhage of Radio Nederland explained a bit about Power Line Communications (PLC) -- a new system that will give very fast Internet connections to people in Europe, but will also interfere severely with shortwave listening. "It’s very dangerous for our broadcasts," said Jan-Willem. (For more information on PLC, see the "Projects/Links" section of the HFCC web site: www.hfcc.org.) Finally, a few financial matters were discussed.
The Bonn HFCC Conference wrapped up around mid-day on Friday, while many of the participants left throughout the day and on Saturday to return to their respective countries, in most cases much more confident about the clarity of their transmission schedules for the coming six months.
The next two items are summary reports of some of the sessions at the
NASB 2002 Annual Meeting. Reports for other sessions
from this meeting will appear in the next issue of the NASB
Radio Frequency Safety for Shortwave Broadcasters
Ed works in the FCC Office of Engineering and Technology. He has an extensive background in making measurements of RF fields and working to develop government guidance and standards for radiation exposure safety. The present focus of concern in the RF safety community is in handheld communications gear such as cell phones. Being so close to the antenna, the head can be exposed to fields of 100 volts per meter, which at those frequencies penetrate to the brain with very little attenuation. Whether or not this is hazardous has not been determined at this time.
The FCC RF Safety Website www.fcc.gov/oet/rfsafety contains a number of useful references. OET Bulletin 65 (available on the website) gives the FCC standards for RF safety. Ed also recommended that broadcasters take a look at Supplement B of OET Bulletin 65. Two limits are in effect---one for the general population, and one for occupational personnel. The occupational limit is higher than the general population limit, but with the additional measures of awareness and control. The general exposure limit corresponds to absorbing about 6 watts of power in an adult body. The occupational limit corresponds to absorbing about 30 watts of power in the body. Persons exposed to the occupational level need to be aware of the situation (training, posting) and exercise control as to how much time they spend in an area of higher RF levels. Instrumentation is available to measure the field strengths, some of it portable enough to be worn by a worker. Ed recommends that shortwave broadcasters rely on field measurements at their transmitting facilities rather than attempting to determine exposure levels by calculations. He said that both the electric field and the magnetic fields should be measured.
General Population/Uncontrolled Maximum Permissible Exposure (MPE) ramps
down with increasing frequency
from 1.34 to 30 MHz.
Electric Field: 824 volts/meter/frequency (MHz)
Magnetic Field: 2.19 amps/meter/frequency (MHz)
For example, at 18 MHz the electric field limit is 46 V/m and the magnetic
field limit is 122 mA/m.
Because of the effects of earth near an antenna, it is possible for either one of the fields to exceed the safety limits at a place where the limit for the other field is not exceeded. (Somewhat dependent on the configuration and polarization of the transmitting antenna, and the proximity of the radiating elements to the measurement location.) In the clear (“far-field conditions”), either field should give the same result in regard to equivalent power density. If site field strength measurements were made prior to the release of the 1996 standards, it would be wise to revisit the measurement results to compare to the revised standard. Any transmitter site areas in which the field strength exceeds the standards for the general population must be fenced out so that there is no access by the public. Ed is interested in doing some field measurement studies of curtain antennas at shortwave transmitting sites.
Digital Radio Mondiale Today
Don Messer---IBB (and Technical Committee Chairman of DRM)
In the past year, DRM has been very successful in regard to technical
and regulatory matters. The focus will now move to commercialization---building
production transmitter exciters, and designing receivers suitable for consumers.
The research and development and regulatory endeavors of recent years must
now be actualized into practical and widespread consumer application.
The DRM is now working with the issues of intellectual property
rights, both within and external to DRM members. This
involves patent searches and setting up licensing of IPRs.
In April 2001, the ITU approved a system recommendation for
the introduction of digital techniques below 30 MHz. This included
the ibiquity IBOC and DRM systems for long wave,
medium wave, and shortwave. In March 2002, that was modified so that
the DRM approach is the sole ITU recommended system for digital
transmissions in the shortwave bands. The introduction of digital
techniques into the medium wave band is very important for the practicality
of marketing of DRM receivers with shortwave capability.
Long term tests (shortwave and medium wave), are being conducted over different
transmission paths. Tests made in the Near Vertical Incidence mode
in Ecuador within the past year showed that the increased multi-path and
Doppler shifts incurred with this mode pose a serious problem for successful
reception of a digital signal. When you work with a multi-hop path,
audio bandwidth must be traded off against robustness of reception.
Even with this trade-off, the digital mode delivers a much better quality
signal than present analog modes do. One of the important features
of the DRM system is its suppression of the effects of co-channel
and adjacent-channel interfering signals. Don estimates that off-the-shelf
DRM-capable exciters and receivers should be available in 1 ½ -
2 ½ years. Don foresees not a DRM receiver, but
a multi-mode receiver that includes DRM capability.
In April 2002, Digital Radio Mondiale (DRM) President, Peter Senger, said that DRM was still on track with its time schedule to begin SW Pilot broadcasts by the Summer of 2003 following WRC03. In March the ITU amended its recommendation and DRM is now the only digital radio standard for the SW bands.
All the basic modes have been tested, but testing continues as DRM gathers more data on long distance multi-hop transmission and also simulcast modes.
The all-digital signal was demonstrated at NAB 02 in Las Vegas with transmissions coming in from NASB member WEWN in Alabama, Radio Canada in Sackville and Radio Netherlands in Bonaire.
In the next DRM update I will add more about DRM receivers and further test results from the field tests.
AWR Shortwave Equipment for Sale
Greg Hodgson of Adventist World Radio asked at the recent HFCC conference in Germany if any NASB members might be interested in purchasing some shortwave equipment that they are taking out of service.
1 x ABB 250 kW type SK53C3-2P
1 x BBC 100 kW type SK51C3
62 x Telefunken 50 ohm 6 1/8" coaxial matrix crosspoints with motor
13 x Telefunken 50 ohm 6 1/8" coaxial matrix crosspoints without motor
2 x 4 Spinner 50 ohm 6 1/8" coaxial matrix with pneumatic motors
2 x Spinner 50 ohm 6 1/8" coaxial matrix crosspoints for manual
1 x BBC 600 kW 50 ohm 6 1/8" coaxial connection 30 Hz to 30 MHz type
AK56SU electrical control
1 x BBC 600 kW 50 ohm 6 1/8" coaxial connection 20 Hz to 30 MHz type
AK56SU pneumatic control
2 x Telefunken 500 kW STL balancing and transformation lines 5.95 - 26.1
MHz 50-300 ohm
1 x Allgon 250 kW + 100% modulation rotatable antenna 50 ohm coaxial
input, 16 dipole elements, 5.9-30 MHz, 11-14 dBi gain
180 meters 6 1/8" rigid coaxial feedline (in pieces)
22 x 90 degree elbows
32,000 meters of 3 mm Aldrey aluminum cable
3 x BBC 380 V voltage regulators 343-417 V, 100 amp output, 50 cycles
If you have any interest in this equipment, please contact AWR at the following address for further information:
VP for Operations & Engineering
Adventist World Radio
Telephone (303) 448-1875
Fax (303) 998-0259
Additionally, AWR has two 100 kW Thomson transmitters for sale.
These transmitters were installed on the island of Guam in 1987, and are
currently in service there. AWR will replace these transmitters next
year in an effort to standardize all their equipment. They are asking
$100,000 each. If anyone has an interest, or would like more information,
use the same contact information given above.
Adventist World Radio
Assemblies of Yahweh
Family Radio Network
Far East Broadcasting Co.
Fundamental Broadcasting Network
Herald Broadcasting Syndicate
High Adventure Ministries
LeSea Broadcasting Corp.
Radio Miami International
Trans World Radio
World Christian Broadcasting
World International Broadcasters
World Wide Catholic Radio
NASB Associate Members
Continental Electronics Corporation
George Jacobs and Associates
HCJB World Radio
TCI, A Dielectric Company
Thales Broadcast & Multimedia