FET field strength meter - with RF amplification

H A field strength meter is necessary when checking the power output and aerial of transmitters. With this circuit it is possible to measure the energy radiated by the aerial. This is useful not only for hams, but also CB enthusiasts and radio control modellers. For various reasons this type of meter must be very sensitive. First of all, there should be a distance of as many wave lengths as possible between the measuring instrument and the trans- mitter. Secondly, other people will not _........, ... with R F amplification be jumping in the air for joy when you are calibrating the aerial with a strong carrier signal. A weak signal will suffice when using a sensitive field strength meter. Thirdly, most trans- mitters only have a weak output power (for example, 500 mW). FET field strength meter . . . elektor july/august 1982 — 7-39 These are three of the main reasons why our field strength meter is equipped with an RF amplifier stage consisting of a Dual gate MOS-FET, Ti. The a...