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 26 - Issue 175

August 2, 1999 - Issue 176 Final Edition

FCC International Bureau Satellite Applications / Correction (July 30)
GE American Communications, Inc., filed an amendment to its request for an STA to permit it to test its GE-4 satellite for a 90 day period at 72 degrees West Longitude, rather than 81 degrees West Longitude, as requested in its May 25, 1999 filing. The FCC Public Notice said GE-4 was formerly known as GE-3, but this was not explained.

The Public Notice also said the EchoStar Satellite Corporation modification application, which was listed last week, appeared in error. The FCC said EchoStar's entry on that Notice was cancelled and the application has been removed from Public Notice.

For additional information, refer to the Public Notice pnin9148, available only as an Adobe Acrobat PDF file.

FCC Extends Special Temporary Authorizations For Use of INTELSAT Satellites Transferred to New Skies (July 30)
When INTELSAT chose to transfer several of its satellites to New Skies, U.S. earth station operators had to file applications with the FCC for permission to access these satellites. On November 30, 1998, the FCC granted over 90 STA (Special Temporary Authority) requests to allow earth station operators using INTELSAT satellites to continue to provide service when these satellites were transferred to New Skies. The STAs expire July 30, 1999. Citing a need for additional time "to consider all issues raised in the underlying applications requesting regular authority to operate with the New Skies satellites," the FCC extended the STAs' term for 30 days, until August 29, 1999, under the same terms and conditions specified in the November 30,1998 STA Order and the June 9, 1999 STA Order.

See the FCC International Bureau Order DA 99-1515 for additional information.

INDUSTRY - Acrodyne Expands Management Team (July 28)
When Sinclair Broadcasting announced a major investment in transmitter manufacturer Acrodyne Industries and secured a positions on the Board of Directors (See the November 25, 1998 RF Current), changes were expected. Today, Acrodyne announced additional expansion of its management team. In its efforts to improve manufacturing processes, Acrodyne found talent outside the broadcast industry. Valerie A. Adams joined Acrodyne as an Advanced Industrial Engineer. Francis X. McCabe, who facilitated continuous improvement programs at Laser Magnetic Storage International and North American Dragger, becomes Acrodyne's Manager of Manufacturing. Jeffrey L. Craft, a Senior Manufacturing Engineer with over twenty years of experience in the semiconductor assembly equipment industry , will be responsible for "analyzing, restructuring and optimizing Acrodyne's manufacturing production processes." Adams, McCabe and Craft will report to William H. Barclay, Vice President, Manufacturing.

Refer to the Acrodyne Press Release for more information.

TECHNOLOGY - New Electrical Transformer Design Will Improve Power Quality, But Will it Be Reliable? (Aug.)
According to a Purdue University News Release, an engineering consortium led by Purdue University and the University of Missouri have developed a new class of power transformers that can "smooth out the uneven voltages that plague today's grid and prematurely age electrical hardware ranging from light bulbs to motors to power supplies in electronic equipment." The News Release called it a "solid-state transformer" Closely examining the photo in the News Release, the transformer appears to consist of several rectifiers and switching modules in series. The device shown in the photo is transforming a 7.2 kV high voltage feed (bottom of the photo) to 120 VAC current to light the lamps shown at the opposite end of the table.

This work is sponsored by Asea Brown Boveri, Zurich, Switzerland. The company owns all rights to the solid-state transformer, which Scott Sudhoff, an associate professor in the Purdue School of Electrical and Computer Engineering, said was recently patented. He expects it to replace existing technology over the next decade. The solid-state transformers have the advantage that they do not require mineral oil for insulation and consume less power from transformer losses than conventional transformer when not supplying power. The transformers should also be less expensive to construct, since they are based on semiconductor technology, which is dropping in price.

The transformers are being developed by the Energy Systems Analysis Consortium (ESAC), consisting of Purdue, the University of Missouri-Rolla, the University of Wisconsin-Milwaukee, the U.S. Navy Postgraduate School and the U.S. Naval Academy.

How well will these solid-state "switching" transformers work in the real world? That remains to be seen. Broadcast engineers are familiar with the problems switching power supplies encounter in high voltage environments and at locations where lightning strikes are a problem. While it is not clear these solid-state transformers will be capable of supplying a site with multiple 100 kW UHF IOT transmitters, they appear capable of improving power quality in residential and light industrial areas.

DIGITAL TELEVISION STATION APPLICATIONS - See ap990727.txt for more information
Call (DT) Ch. Licensee Location ERP (kW) HAAT (m) Antenna
WTHR 46 VideoIndiana Indianapolis IN 1000 284.7 Dielectric TFU-30GTH04
WJWN 39 S&E Network San Sebastian PR 50 324 Dielectric TLP-16C(C)
WJPX 21 S&E Network San Juan PR 50 564 Dielectric TLP-16M(C)
WKPV 19 S&E Network Ponce PR 50 288 Dielectric TFU-34DSC C170 DC
WFXB 18 JME Media Myrtle Beach SC 1000 459 Andrew ATW-25-H3H-ET1-18S
KPXB 5 Paxson Houston Conroe TX 8.0 603 Dielectric TF-2CM P200


OTHER Items of Interest

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Last modified August 2, 1999 by Doug Lung dlung@transmitter.com
Copyright 1999 H. Douglas Lung