Newsgroups: sfnet.harrastus.dx-kuuntelu Path: news.cs.tut.fi!news.funet.fi!ngw From: rko@CC.JOENSUU.FI (Risto Kotalampi) Subject: Radio Finland/VOA Tests Message-ID: <9312021009.AA14197@cc.joensuu.fi> Sender: daemon@funet.fi (#) Organization: Finnish University and Research Network FUNET Distribution: sfnet Date: Thu, 2 Dec 1993 10:09:17 GMT Lines: 57 Forwarded message: > From bc@beryllium.lexicon.com Thu Dec 2 02:21:43 1993 > Date: Wed, 01 Dec 1993 16:37:02 > From: bc@lexicon.com (Bruce Conti) > To: rko@cs.tut.fi > Subject: Radio Finland/VOA Test Radio Finland and the Voice of America are cooperating in a joint experiment to measure and document the audio signal delivery performance of SSB suppressed carrier HF transmissions in direct comparison with that of double sideband full-carrier (A3) transmissions. The purpose of this test protocol is to evaluate the audio signal delivery performance of fixed-peak-power suppressed-carrier Single Side Band (SSB) transmission, relative to fixed peak-power Double Side Band (DSB) transmission. Performance will be evaluated from measurements and analysis of audio signal at the output of the detector. The initial transmissions will use envelope AM (peak detector) mode demodulation. When conclusive measurements are obtained from this experiment, further tests using product LSB/USB (lower side band/upper side band) demodulation and -12 dB suppressed carrier may be performed. Performance measurements include audio signal power, distortions from ionospheric propagation effects and peak detector effects and effects of atmospheric noise on the audio signals. The experiment will be performed for a sufficient length of time so that a broad variety of broadcast conditions will be encountered and so that statistical significance in the measured and analyzed results may be achieved. Transmissions will originate from the Radio Finland facilities in Pori. VOA facilities in Munich will be the site of the first receiver combination. Another location will be identified for a second record/analysis set. This announcement is an invitation for other interested parties to participate by performing their own analysis of signals directly received from the transmissions, or to perform their own analysis on the data sets as received and analyzed by Radio Finland/Voice of America. For more information, or to arrange to receive the data sets as received and analyzed, please communicate with one of the following: Mr. Esko Huuhka Finnish Broadcasting Company, HF Planning OY YLEISRADIO AB, Engineering Division P.O. Box 20, SF-00521 Helsinki, Finland Robert Everett Voice of America, Systems Engineering B/ESB, Bureau of Broadcasting U.S. Information Agency 330 Independence Avenue SW Washington, DC 20547 USA 73s Forwasi: Risto Kotalampi