RF CURRENT



Welcome to RF Current, a weekly electronic newsletter focusing on Broadcast technical and F.C.C. related issues. This newsletter is part of The RF Page @ www.transmitter.com, a web site devoted to TV Broadcast RF engineering. For more information see the What is... guide to the R.F. Page site.

Issues are dated each Monday, although recently I've needed an extra day or two to complete each issue. Articles may be posted earlier if time permits or if there is a major, breaking story.

<<< Back to July 19 - Issue 174

July 26, 1999 - Issue 175 Final Edition

FCC Proposes Changes to Spectrum Above 50 GHz (July 26)
The FCC issued a Notice of Proposed Rule Making on July 23 that would amend its frequency allocations in the 50.2-50.4 GHz and 51.4-71.0 GHz bands. The FCC proposed to allocate the 65-71 GHz band to the inter-satellite service (ISS) and delete non-government ISS allocations from the 56.9-57.0 GHz and 59-64 GHz bands. 64-65 GHz would be allocated to the Government ISS on a primary basis. Government and non-Government fixed and mobile services would be allocated 51.4-52.6 GHz, 58.2-59.0 GHz and 64-65 GHz. Unused fixed and mobile service allocations at 50.2-50.4 GHz and 54.25-55.78 GHz would be deleted. The bands 57-59 GHz and 64-66 GHz would be made available for both Government and non-Government unlicensed devices. Government and non-Government earth exploration satellite (passive) and space research (passive) services would be allocated 59.0-59.3 GHz. Existing passive sensor allocations at 51.4-52.6 GHz and 64-65 GHz would be deleted.

The FCC did not address technical rules for unlicensed use of the 57-59 GHz and 64-66 GHz band in this NPRM, other than stating operation the 57-59 GHz range would not be permitted on aircraft or satellites. Technical rules will be considered in a separate rulemaking. The FCC sought comment on technical rules for this spectrum.

More detailed information, including technical details, may be found in the FCC Notice of Proposed Rule Making.

FCC Modifies TV Table of Allotments in Buffalo NY (July 23)
The FCC said it will grant Western New York Public Broadcasting Association's request to reserve channel 17 and its associated DTV channel 43 for noncommercial educational use and simultaneously change the reserved status of channel 23 and associated DTV channel 32 to commercial. WNED-TV, channel 17 is the main public television station in the Buffalo market. WNEQ-TV, channel 23 is also owned by Western New York Public Broadcsting. The owner plans to sell WNEQ-TV and use the proceeds to improved WNED-TV. For details on this proceeding, refer to the FCC Report and Order (DA 99-1442).

FCC Satellite Applications (July 22)
PanAmSat has filed an amendment to change its application for PAS-12 from a hybrid C/Ku band satellite to a C-band only satellite. PanAmSat also filed an application changing the designation for its proposed hybrid C/Ku band Galaxy II(H) satellite to Galaxy XI. It also requested authority to operate the satellite at 91 degrees west longitude, rather than 74 degrees WL, with an interim assignment at 99 degrees pending the launch of Galaxy IV-R. Galaxy IV failed in May 1998. PanAmSat is currently using Galaxy VI, a C-band only satellite, to provide service from 99 degrees.

EchoStar Satellite Corporation requested modification of its DBS authorization for operate at 61.5 degrees WL. EchoStar is currently authorized to operate 11 even-number channels 2-22 at this location. EchoStar seeks permission to operate on the two assigned channels (23 and 24) at 61.5 degrees W.L.

DirecTV requested Special Temporary Authority to operate its DBS-1R DBS satellite at 82 degrees W.L. for an eight week period after it is launched. The ultimate location of DBS-1R will be 101.2 degrees W.L.

This information was taken from the FCC International Bureau Public Notice (pnin9140)(Adobe PDF file).

SCIENCE - Scientist Study New Methods for Predicting When the Sun Will Be Most Active (July 22)
Ham radio operators, satellite operators and even power companies are interested in solar activity. High solar activity impacts radio communication, both through "skip" through the ionosphere and via satellite. Geomagnetic storms associated with high solar activity can impact power grids. Since 1843, astronomers have known that sunspots come and go in roughly eleven year cycles. Sunspots are an indicator of high solar activity.

Dr. David Hathaway, working with Robert Wilson and Ed Reichman at NASA's Marshall Space Flight Center, have examined different methods for predicting sunspot activity. The results of their research will appear in "A Synthesis of Solar Cycle Prediction Techniques" in the Journal of Geophysical Research. Hathaway explained "There are many different ways of predicting the sunspot cycle, but until now there has never been a systemic study to determine whether one method works better than another. After examining various methods, we found that some of the techniques currently used and touted are basically useless."

The team looked at over 15 methods for predicting solar maxima and found 8 or 9 were better than average. The best methods used information from disturbances in the Earth's magnetic field, which are caused by disturbances in the Sun's magnetic field. Describing the Sun's magnetic field, Hathaway said "The magnetic field is a lot like a rubber band. Fluid flows within the Sun called 'dynamos' stretch, twist and fold the band, wrapping it around the sun many times over 11 years. When the magnetic field loops into the Sun's convective zone, it rapidly rises to the surface. As it rises, it twists a little bit. This provides a change in field direction that helps to reverse the poles."

However, Hathaway said, "physical models to predict sunspot activity several years in advance are not available. We don't understand well enough why the sun does this to be able to predict like a meteorologist does." Solar activity is expected to remain high, with sunspot numbers between 100 and 200, from now until mid 2001.

For more information on this subject, including graphics showing the Sun's magnetic field, refer to the NASA Marshall Space Flight Center July 22 Headline article.

>>> Next: August 2 - Issue 176 >>>

DIGITAL TELEVISION STATION APPLICATIONS - See ap990722.txt for more information
Call (DT) Ch. Licensee Location ERP (kW) HAAT (m) Antenna
KVHP 30 National Communications Lake Charles LA 1000 315 Andrew ATW25H3-HST2-30S
WLBT 51 Civic License Holding Jackson MS 1000 634 Non-directional
WOLO 8 So. Carolina B'cstg Columbia SC 43.7 533 Dielectric THV-6A8R
WWPX 12 DP Media License Martinsburg WV 30 288 Dielectric THP-O-4-1
WHRM 24 Wisc. Ed. Comm. Wausau WI 200 387 Non-directional


DIGITAL TELEVISION STATION APPLICATIONS - See ap990721.txt for more information
Call (DT) Ch. Licensee Location ERP (kW) HAAT (m) Antenna
KSNG 16 Wichita License Garden City KS 1000 234 Harris TAD-20UDA-5/50-RST
WHAS 55 Belo Kentucky Louisville KY 1000 370 Dielectric TFU-26DSC-R CT160


DIGITAL TELEVISION STATION APPLICATIONS - See ap990720.txt for more information
Call (DT) Ch. Licensee Location ERP (kW) HAAT (m) Antenna
KSNW 45 Wichita License Wichita KS 891 317 Harris TWSC-20
KSNK 12 Wichita License Mc Cook NE 10.6 216 Harris TAB-12H-M
KMAZ 47 KMAZ Las Cruces NM 52.5 131 Dielectric TFU-32DSC-R P300BNT
KOPB 27 Oregon Public B'cstg Portland OR 710 (mod) 509 Dielectric TFU-24GBH-R06


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Last modified August 1, 1999 by Doug Lung dlung@transmitter.com
Copyright © 1999 H. Douglas Lung