Kiefer  Electronic  Development - WIRELESS

     RF Engineering Consultancy - Richard Kiefer, Principal

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 Antenna Designs
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KED has designed several VHF/UHF antennas for portable operations.


318MHz Yagi -

This is a five element hand held Yagi for 318 MHz which is used with The EMI Finder, an electromagnetic interference sensing receiver.  The forward gain is high and the beam width is narrow to pinpoint radiators of electromagnetic interference with precision.  The antenna is computer optimized using the program Yagi Optimizer.  The construction is from tape measure material so that the elements are flexible and can bend without breaking.  The boom is made of PVC plastic.









146MHz Yagi (indestructible) -

This is a three element hand held Yagi for 146MHz used for Fox hunting in the two meter Amateur Radio band.  This antenna is computer optimized for high front to back ratio instead of high forward gain to provide the best directivity.  The impedance matching network is built into the boom



146MHz Yagi (light weight) -

This three element hand held Yagi is also for 146MHz and is constructed from thin steel wire elements.  It is extremely light weight, 5oz, and easily disassembles for remote backpack operations.  It can be assembled or disassembled in minutes using one Allen key wrench.  This antenna is computer optimized for maximum forward gain to provide the most efficient communications using low powered hand held VHF radios from remote mountain locations.


497 MHz Yagi for HDTV -

This 10 element experimental Yagi provides 12 db of gain at 497 MHz for high definition television reception on DTV channel 18, Public Broadcasting in Denver.  It has high front to back and high front to side ratios with a flat pass-band important for HDTV reception.





Big HF Yagis for 14 to 30 MHz -

We have designed and constructed several very large Yagi antennas for HF operations in the 14 to 30 MHz range of the spectrum.  These are all computer optimized for radiation pattern, forward gain and front to back ratio.  Measurements have been made to verify the pattern shape in relation to the computer simulations.  They are used for world-wide single side-band (SSB) voice communications in the Amateur Radio bands.

Contact - Richard Kiefer: 303-449-4700 (Colorado, USA - MST)