Looking at getting a SA for amateur radio and RF work-mostly characterizing filters and checking for spurious emissions. Doesn't have to be elaborate, I have limited access to a very nice spectrum analyzer if I need it, but it'd be nice to not have to use it all the time.
There are plenty of HP859X SA's on ebay often enough, and most of them go just over my budget, or are very broken. Except the 8591C Cable TV analyzer. I see them sell for as little as 300 bucks, because of the 75 ohm inputs and the 1Mhz to 1.8Ghz range. I rarely need anything less than 1.5Mhz in an SA, so the low end not going to 9Khz doesn't bother me, and I can live with the 1.8Ghz upper range-if I need to go higher I can ask to visit the lab with the 40Ghz SA for a bit.
So, if I was to acquire a working, decently closely calibrated 8591C Cable TV Analyzer, it would have the following options that I'd like to change:
75 ohm inputs/outputs via option 001
75 ohm tracking generator via option 011
From some limited googling, people have done this by changing the front panel connectors, exchanging two resistors on a board for the input impedance match, and using a 75 to 50 ohm minimum loss pad for the tracking generator impedance match.
Has anyone else done this? The -C units have some useful hardware for filter measurment and noise figures programmed in by default, as part of the CATV personality, but getting good quality test leads and probes for SA use is much easier with SMA or N connectors. (Also, having lived the life of a CATV installer and using BNC's for satellite link work, I have to say I prefer the threaded connectors.) On the other hand, BNC's are designed to have a few more connection cycles by nature of the quick-disconnect coupling-so it's really just the 75 ohm impedance issue.
Other options might include an E4401B if I can save up some more money, or wait another year and get the one of the Siglent units. the tracking generator is pretty much a requirement, which pushes the cost of the siglent up into the range of buying a used HP/Agilent