I think that the '17 is substantially the same as a '16, just a "face-lifted" model; there is an LSG-16 manual on BAMA.http://bama.edebris.com/manuals/leader/lsg16/
This kind of instrument is not a "serious" signal generator; they drift in frequency, they leak signal and they do not have a good output attenuator (nor is the output impedance 50-ohms).
Whilst the LSG-16 has a co-axial Motorola output connector the LSG-17 has banana-post output terminals; not the sign of a "serious" signal generator.
I have a '16; I bought it for a few $$$s because it was cute and because I thought it might be a useful "VFO" for experiments with mixers and receivers. I only had one good signal generator (Rohde & Scwartz SMS) at the time and two generators are useful for such work.
I built an output amplifier to give a 50-ohm output impedance; that was useful but the drift and the RF leaks still remained. I haven't used it for a long time.
I later built a DDS kit ( http://www.minikits.com.au/kits5.html
) and put it in a metal box; I replaced the MMIC output amplifier with a discrete-transistor one to reduce the harmonics and this works quite well. I set the output at +10 dBm to use with mixers that require either that drive level or a drive level of +7 dBm when a simple 3 dB attenuator does the job.
Still later I "bit the bullet" and bought a HP8657B so I now have two good signal generators but I still use the DDS one sometimes as it's quite small on the bench and I sometimes find a tuning knob more convenient than a push-button.
I wouldn't pay a lot for the LSG-17; if it's going for $20 or so it might be fun to play with but I wouldn't pay serious money for it.