For clarification: A SWEEP GENERATOR is just a sweep generator by itself and is generally used with a diode detector and a scope to view the output signal of whatever is being swept. The sensitivity (dynamic range) is limited by the sensitivity of the diode which is usually in the neighborhood of -40 dbm. So if your sweep generator puts out zero dbm then you can see down to -40 dbm in level. Good for tuning pass band cavities or IF filters etc. but not enough sensitivity to tune a notch filter where you need to see down at least -70 to -80 db or more. You can add an amplifier before the diode detector or to the output of the sweep generator to gain a little more range but if you go much over 20 db in gain you start running into overload problems with the auxiliary amp.
A TRACKING GENERATOR uses the same type of sweep generator as above but rather than using a simple diode detector to view the output a spectrum analyzer is used as the detector. The spectrum analyzer will have a sensitivity in the range of -80 to - 100 dbm or so. With the sweep generator set for an output of zero dbm, you will be able to see the signal down to the -80 to -100 dbm level. The sweep generator operates in sync with the spectrum analyzer so that they are both on the same frequency at the same time. In other words they sweep the particular range of frequencies together. It is like using a tunable receiver and a tunable signal generator and moving them both with one hand on each tuning knob so as to move them together. A service monitor with just a sweep generator is usually not able to perform as a tracking generator because the monitor does not have the capability of generating and receiving simultaneously, which is a requirement for a tracking generator. A service monitor with a DUPLEX GENERATOR will have the ability to generate on one frequency and receive on another in order to test repeater operation. Some of those type monitors have a fixed signal generator level output in the duplex mode and some are adjustable in level. They may or may not have the capability to generate and receive on the same frequency at the same time which is required of a tracking generator. To function properly as a tracking generator they must also have sufficient isolation between the signal generator output and the spectrum analyzer input which some do not that are only intended for duplex operation and not specifically to function as a tracking generator. 73 Gary K4FMX
