Measured Noise Figure Trends

The use of new noise figure (NF) test gear (ie, HP-8970A with a properly corrected HP-346A noise head) is providing more meaningful data in the NF contests at various conferences. While VHF + ers may disagree on the desirability of the lowest NF for certain bands and modes, there is evidence that the use of GaAsFETs in a receiver's front end is highly beneficial in at least two other respects. The level of RF input necessary to destroy the device is generally greater than with a bipolar...

Print Routine for the Computerized Smith Chart

Sontag, PE, N0CAO Lake Farm, Rt 1, Box 47 Tebbetts, MO 65080 KO0P, Computerized Smith Chart Program, in a previous issue of Q X.1 At last, a program for noise-bridge applications that eliminates the tedious calculations always associated with the use of the device. Though the author stated that he developed this C64 program because he wanted the option of having a hard copy of the entry data and results, he provided no print feature. I believe many amateurs like to file a hardcopy of...

Bridge Method of Sweep Frequency Impedance Measurement

By Ken Simons, W3UB 2035 Willowbrook Dr Huntingdon Valley, PA 19006 Since high-frequency measurements frequently require unavoidable lengths of transmission line, HF measuring techniques usually involve an application of transmission-line principles. The bridge circuit to be described is no exception. Understanding its operation requires a clear picture of the concepts of reflection coefficient and return loss. Consider an ac generator with an internal impedance R0 and a voltage E as...

Adventure

Tommy Rockford, K8ATX is back on the trail of high adventure In Death Valley QTH, what starts as a typical field day operation becomes a matter of life and death for K6ATX and the Santa Bonita Amateur Radio Club. SOS at Midnight finds Tommy up against the Purple Shirt Mob and ham radio saves the day The beachcomer seemed like a harmless character, but what did he have to hide in CQ Ghost Ship Underwater adventure and ham radio join together to form the exciting conclusion to DX Brings Danger....

Icom Rr Computer Interface

2M 70cm 23cm precision receivers, transmitters, converters, pre-amps, IF strips, ATV. Specialists in FMTV. MICROWAVE NEWSLETTER TECHNICAL COLLECTION Packed with microwave construction projects and information organized on a band-by-band basis. Begins at 1.3 GHz and covers up through 24 GHz plus millimetric bands. 40 pages are devoted to 10 GHz alone This book was compiled by Julian Gannaway, G3YGF and Steve Davies, G4KNZ. It is a reprint of the technical material contained in the Microwave...