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 August 30 - Issue 180

September 6, 1999 - Issue 181 Final Edition

FCC Sets New Rules for Amateur Radio Use of Spread Spectrum Technologies (Sept. 3)
The FCC, in a Report and Order (FCC 99-234) released Friday, made major changes to its rules for spectrum spectrum connumications in the Amateur Radio Service. The FCC will allow spread spectrum emissions using bandwidth-expansion modulation with FCC designators A, C, D, F, G, H, J or R as the first symbol, X as the second symbol and X as the third symbol. In addition, a station may transmit a test emission on any frequency authorized to the control operator, provided the frequency is authorized for pulse and/or spread spectrum modulation, as applicable.

Transmitter power is limited to 100 watts under all circumstances. Furthermore, if more than 1 watt is used, FCC Rule 97.311(d) now requires automatic transmitter control to limit output power to that required for the communication. It states "This shall be determined by the use of the ratio, measured at the receiver, of the received energy per user data bit (Eb) to the sum of the received power spectral densities of noise (N0) and co-channel interference (I0). Average transmitter power over 1 W shall be automatically adjusted to maintain an Eb/ (N0 + I0) ratio of no more than 23 dB at the intended receiver."

The FCC relaxed recordkeeping and station identification rules to bring them in line with those required for other emission types. Refer to the Report and Order (FCC 99-234) for details.

SOFTWARE - Andrew Releases Free Powertools Telecomunications System Planning Software Suite (Aug. 31)
Andrew Corporation has upgraded and combined its RF system planning tools into an integrated package on one CD. The Powertools CD-ROM contains seven programs suitable for designing PCS and cellular systems, DTV and NTSC broadcast systems and terrestrial microwave systems. Some of the applications include the ANTDES(TM) microwave antenna selection tool, AntWind(TM) for calculation of wind loading of Andrew parabolic antennas, ezGuide(TM) for microwave transmission line planning, and the Andrew Broadcast System Planner.

The Broadcast System Planner creates antenna patterns (both azimuth and elevation) and does a power analysis for broadcast antennas. The program contains pattern data for Andrew's standard broadcast antenna patterns and will calculate loss and evaluate power handling capability for over 35 popular transmission lines, including several from other manufacturers. The program can supply the data in printed form for use on FCC applications or in electronic form for use with RF propagation software.

More information on the software is available on the Andrew System Planning Software page. Note that you must fill out a registration form on the way to the download page. On the registration page you are given the choice of having the CD-ROM mailed to you or downloading the individual software package. This information was obtained from the press release Announcing Andrew Powertools Telecommunications System Planning Software.

TECHNOLOGY - Hewlett Packard Labs and UCLA Developing Computer Based on Nano Resources
Many years ago, Intel's Gordon Moore observed that the growth in complexity of intergrated circuits and now, by extension computer chips, was increasing at an exponential rate. The accuracy of this observation has resulted in it being widely known as "Moore's Law". The growth in complexity, which requires smaller and smaller transistors, is running up against the limits of conventional chip manufacturing technology.

HP Labs, along with UCLA scientists, are working on new chip architectures and quantum phenomena switching circuits on a scale of nanometers. HP Labs found a way to fabricate a parallel array of wires, each 2 nanometers wide. The wires are "self-assembled" using a chemical reaction between silicon and erbium. This tehcnology, combined with the development of a working molecular switch, will lead to new type of computer. HP Labs researcher Stan Williams said, "This computer of the future would supply much more computing power than current workstations and could easily fit inside of a wristwatch or other wearable appliance."

More information on this technology may be found in the HP Labs feature article on nano technology.

DIGITAL TELEVISION STATION APPLICATIONS - See ap990903.txt for more information
Applications for license to cover construction permit:
WOOD-DT CH 7 Grand Rapids MI
WNYW-DT CH44 New York NY
WKPC-DT CH17 Louisville KY
Call (DT) Ch. Licensee Location ERP (kW) HAAT (m) Antenna
WXMI 19 Tribune Television Grand Rapids MI 155 306 Dielectric TLP-24A(C)
WITN 32 WITN Licensee Washington NC 795 594 Dielectric TFU-30GTH-04


DIGITAL TELEVISION STATION APPLICATIONS - See ap990902.txt for more information
Call (DT) Ch. Licensee Location ERP (kW) HAAT (m) Antenna
WCPX 43 Paxson Chicago Chicago IL 200 437 Dielectric TUP-SP4-12-2-R
WYMT 12 WYMT License Hazard KY 50 468.2 Dielectric TBF-03-3-1-R
WMDN 26 WMDN Meridian MS 1000 165.2 Dielectric TFU-28DSC-S180


OTHER Items of Interest

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Last modified September 11, 1999 by Doug Lung dlung@transmitter.com
Copyright 1999 H. Douglas Lung