Broadcast Technical Consulting and Sales
Built by M. W. Persons and Associates, Inc.
|This handy device is for setting
calibrations on VSWR (Voltage Standing Wave Ratio) meters, otherwise
known as forward and reflected power meters commonly used on FM
broadcast transmitters. The inspiration was an article
written by Steven Rutherford in the Broadcasters' Desktop Resource and
was built for radio broadcast engineer Jim Offerdahl at his urging.
Modified from the original concept, this instrument can help a radio
broadcast engineer set reflected power meters and trip/fold back
protections for transmitters.
|Very simple and straightforward on
the inside. Easy to maintain.
|Just 6" x 2.5" x 2", it is run on
three AA batteries. A switch selects either a positive or a
negative polarity metering sample to a transmitter's metering system.
A green light indicates the outgoing 0 to 4.5 volt DC sample is negative
in relation to its shield on the BNC connector. If the light is
red, it means the sample is positive. A switch, with a center off
position, selects which will be employed.
It all depends on the brand and model of transmitter this box might
be connected to.
is a PVC protector to keep the switch safe from breakage and to prevent the
switch from being accidentally turned on.
A 10-turn output level control is used to carefully set the outgoing DC sample level for setting reflected power metering and transmitter protection circuits. This requires a jeweler's screwdriver. In addition, there are two blue tip jacks for a voltmeter to read the exact voltage being put out by the instrument.
The cost for a
VSWR Calibrator is
Questions? Email Mark Persons: firstname.lastname@example.org
page last edited 02/22/2016