A Three to One Dummy Load

Bryce, Mike
February 2013
QST;Feb2013, Vol. 97 Issue 2, p30
The article describes the creation of a 3:1 standing wave ratio (SWR) by making an appropriate resistive load. Changing inductance or capacitance is also a way to change the SWR. It cites the need for a radio frequency (RF) detector to provide visual indication of power applied to dummy load. The dummy load is intended to calibrate SWR meters and check for proper transmitter foldback. The importance of proper heat sinking of the resistors is also discussed.


Related Articles

  • The Arch on Other Bands.  // QST;Jan2008, Vol. 92 Issue 1, p40 

    The article provides tips for matching a relatively short whip in radio equipment and antenna to allow operation on any high-frequency or even mid-frequency band. The downside however, is that the tuning becomes critical, the bandwidth for reasonable standing wave ratio is reduced and the...

  • Design and Simulation of Q-Enhanced CMOS RF Active Inductor Based on Negative Resistance. Meshkin, Reza; Niaboli-Guilani, Mohammad // Journal of Electrical & Electronics Engineering;May2012, Vol. 5 Issue 1, p133 

    This paper presents the design of a single-ended CMOS radio frequency (RF) active inductor for use in applications around 2-2.4 GHz, that is suitable for RFfiltering and many other applications in RFIC design. Our approach is based on a conventional grounded active inductor topology, where added...

  • Program predicts VSWR-mismatch RF uncertainties. Hageman, Steve // EDN;02/01/2001, Vol. 46 Issue 3, p124 

    Focuses on calculating the uncertainty in radio frequency (RF) measurements from voltage-standing-wave-ratio (VSWR). Determination of RF power measurements; Inclusion of VSWR values in the system specifications; Details on the uncertainty in the total measurement stemming from the source and...

  • Grounded resistor tunes oscillator. Tepin, Vladimir // EDN;5/29/2003, Vol. 48 Issue 12, p78 

    To vary the frequency of any sine-wave oscillator, a pair of ganged variable resistors should be used and characteristics of both should be matched, over the entire variation range, to satisfy the oscillator's balancing conditions. This restriction leads to problems in the tuning range and high...

  • Measuring Inductors and Capacitors at RF Frequencies. Carr, Joseph J. // Electronics Now;Jul99, Vol. 70 Issue 7, p40 

    Takes a look at several effective methods for measuring inductance and capacitance at radio frequency frequencies. Voltage standing wave ratio; Voltage divider method; Signal generator model; Frequency-shifted oscillator method; Set-up for finding the series-resonant frequency.

  • Secondary Ignition The Art of Spark. Weaver, Scott "Gonzo" // ImportCar;Aug2015, Vol. 37 Issue 8, p30 

    The article discusses ignition systems of automobiles including step-up coils, inductance of current flow in the coil, and capacitance between the coil windings.

  • A Signal Generator for the VHF Operator. Pivnichnny, John // QST;Oct2010, Vol. 94 Issue 10, p34 

    The article describes the design of a generator that has the ability to develop a clean fundamental signal for experimenting in the very high frequency (VHF) range. It discusses the use of the generator to perform receiver and filter alignment tasks and serve as a source for measuring antenna...

  • Formation and manipulation of two-dimensional arrays of micron-scale particles in microfluidic systems by surface acoustic waves. Wood, C. D.; Cunningham, J. E.; O'Rorke, R.; W√§lti, C.; Linfield, E. H.; Davies, A. G.; Evans, S. D. // Applied Physics Letters;2/2/2009, Vol. 94 Issue 5, pN.PAG 

    The two-dimensional concentration and manipulation of micron-scale particles by orthogonal, surface acoustic, standing waves is demonstrated. The particles are organized by liquid pressure waves in a microfluidic system over a piezoelectric substrate and form a uniform two-dimensional array with...

  • Self-compensated standing wave probe for characterization of radio-frequency plasmas. Ta-Lun Sung; Shosaku Matsumura; Kungen Teii; Shinriki Teii // Review of Scientific Instruments;2014, Vol. 85 Issue 6, p1 

    A simple self-compensated Langmuir probe using the character of a standing wave is developed for characterization of radio-frequency (RF) discharge plasmas. This probe is based on a concept that the interference of RF field is eliminated at the node of a standing wave which exists ideally at...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics