Coming Attractions

(Remember, software upgrades are free ) WEFAX and SSTV demodulators Commercial inquiries are welcomed. We offer rapid prototyping of custom commercial, civil, and government applications including intelligent radio, wireline, and telephone modems. DSP-12 Multi-mode Communications Controller ---- One Megabyte RAM Expansion Option Date Time Clock Backup Option 8-Channel A-To-D Telemetry Experimentation Option Wall-Mount Power Supply for DSP-12 (110 vac) We accept MasterCard & VISA and can ship...

All About Phase Noise In Oscillators

Part 1 How Oscillator Noise is Described and Analyzed One of the key measurements of oscillator operation is the signal-to-noise ratio of the oscillator at certain offsets from the carrier. Ideally, the output of the oscillator would consist of only a single-frequency signal, but in reality there is energy noise at nearby frequencies as well. Although oscillator amplitude variations will result in sideband energy, most of this noise is phase noise, main sources of which are the flicker noise...

87c51 Programming

87c51 Programmer

Project making use of the features of the 8051 family. Rather than build an 8051 development system like I did with the 8085 computer, I took the lazy approach and bought one for about 100. It was similar to my 8085 system in layout, but it had a very poor operating system in its EPROM. Using the existing 8085 computer I was able to program a 2764 EPROM with a better and more flexible operating system for the 8051. This system was then fine for development and learning the 8051 system, but my...

Index

March 1993-December 1993 QEX Volumes 133-142 Better Iron-On PC Patterns Elmore 21, Jun 93 TCP IP for Networking Gallaher 20, Jun 93 Windows Standards New 20, Jun 93 Audio Spectrum Analyzers Cheap 13, Dec 93 Correction for GRAPES Address 15, Dec 93 Embedded Processors Made Easy 20, Aug 93 Forward Error Correction 17, Jun 93 Forward Error Correction II The Preview 15, Dec 93 High-Speed Modems 56 kbps 430-MHz 30, Oct 93 More on Computer Control 19, Jun 93 We're Still Doing it Wrong 23, Apr 93...

Digital Communications

This month's column is about making do with what you have at hand. One of the things Amateur Radio can teach, or at least give you practice at, is cobbling up something quickly out of the junk box, be it a hardware junk box or a software junk box. This month, I'll give an example, and point you toward a very good software junk box. I needed to do a quick check on the center frequency of an audio filter recently. The filter in question was the NIR-10 from J PS Communications, Inc. This is a...

QEX

50-mW, 13-cm Amplifier using the MAV-11 MSA-l 104 MMIC 25, Sep 93 561.6-to-2808 MHz Multiplier 15, May 93 The 561.6-MHz Local Oscillator 15, May 93 2808-to-5616-MHz Doubler 17, May 93 A 5616-MHz Local Oscillator 15, May 93 Central States VHF Conference Comments 23, Sep 93 Designing a High-Performance 13-cm Preamp 20, Nov 93 A No-Tune 222-MHz Transverter 24, Jul 93 A No-Tune Driver for 432 MHz 21, Mar 93 Specialized Communications Techniques All G3RUH Modems Are Not the Same Dubke 14, May 93...