RF test generator

10-38 - elektor october 1981 RF-test generator At one time or another, Ham radio operators who built their own sets are going to need a generator for receiver alignment. A commercially available test transmitter would, of course, be ideal, but they tend to be rather expensive and rather over-sophisticated. In nine cases out of ten a much simpler device will do the job, provided it produces a reliable, stable test signal within the required frequency range. There is, however, one snag: an absol- utely stable generator with an output frequency that is continuously adjust- able is almost impossible to obtain. This measured frequency. The required fre- quency (here: 9005.000 kHz) must therefore be tuned precisely with coil L1. With the aid of the varicap diode D1 the oscillator can be frequency modu- lated. The useable modulation level (presettable with P1) is not particularly high, but high enough to test narrow band FM amateur and other special band receivers. SSB receivers can be "...