texscan vsm-2d manufactured?
Hi Tim, glad to meet you & be able to help. I'll get the scans done within the next couple of days or so & send. I'm sure that the circuits of the "C" and "D" models should be similar, and my manual does refer to the "C" model in places. I'll be glad to post here also.
From what I can tell, there aren't many people using these anymore, and information is nearly nonexistent. The manual which I have seems to be the only one in captivity these days, and it is not very well written nor very detailed. I just bought my unit a few days ago also because I couldn't afford much for an analyzer.
These were built some 25 years ago, primarily for the CATV industry. It has a 75-ohm RF input, so your input signal will need to go thru a 50-to-75 ohm transformer if you are trying to do accurate communications work. The IF bandwidth can be set as low as .5 khz, but when set this low, desired signals tend to drift out of the passband VERY quickly. The 10khz position works ok for this after a good warmup period.
These units can provide reasonable performance if you are patient and allow it to warm up for an hour or so before any serious work.
The main disadvantage which I've found so far is no direct center-frequency readout.
To sum up, its not a Tektronix 494 or a Motorola R2600. But it is still a useful piece of equipment for some purposes.