How are old arbitrary function gens compared to low end modern ones? - Page 1
Forum section: electronics / general

author: poodyp
author_rank: Regular Contributor
timestamp: October 29, 2012, 11:40:10 pm
content: I was looking at old gear on eBay and came acrossthis Stanford DS345with the optional GPIB/RS232 and TCXO that sold for $481 (and others like it, even without the TCXO, sell for around the same). That's the price of a Siglent SDG1050 or almost a Rigel DG1022A.As far as I can tell from the spec sheets, the Siglent and Rigol pretty much beat the Stanford in bit depth, distortion, rise time; the Stanford only has a numeric display, whereas the Rigol has a b/w LCD, and the Siglent a QVGA color TFT; and they have USB (both host and device).So am I missing something? Other than say, a company that's been using a Stanford DS345 for 20 years and theirs broke, or someone really doesn't want an external frequency standard, is there any reason why someone would want this DS345, or say an HP 33** or 86** over a new, modern function generator?

author: Rerouter
author_rank: Super Contributor
timestamp: October 30, 2012, 01:51:59 am
content: part of the reason is, they where built to last before the company closed, most test gear of that vintage had full documentation available, everything from values and tolerances of components to what waveforms to expect at what test points, and how to calibrate the unit,while average joe today might just want a bit of kit, there is a wide popularity of old gear for hobbiests, as its unlikely to fail, and if it should you have more than enough info to repair the thing in under a day,and for why they are unlikely to fail... Google "tin whiskers"

author: ejeffrey
author_rank: Super Contributor
timestamp: October 30, 2012, 05:15:49 am
content: SRS produces great stuff. Their designs are solid, textbook brute force solutions and well executed. They can be relied on to meet their specs, their computer interfaces are simple and well documented, and they have relatively few corner cases where the top line specs only apply under a full moon. For instance, that siglent... according to the manual the TTL sync pulse only works up to 2 MHz. Many people don't care, but if you do, it is a boat anchor. Jitter is another spec that many AWGs are bad at. IIRC, the SRS is not great, but I wouldn't be surprised if the siglent was worse. Who knows what else you would find if you dig through. They are are also generally have the full schematic available in the manual and are easy to service given the low level of integration. There are some problems sourcing obsolete parts (monolithic matched JFETs...), but generally they are rock solid.So yeah, I would probably buy a used SRS wavegen over a new siglent with slightly better specs at the same price. In 20 years I will still have a working used SRS, and you will probably be on your 3rd new cheapie. Hard to say who wins. By that time your 3rd generation chepie will have way better specs than my SRS, but I will be pretty confident in its strengths and limitations.

author: LEECH666
author_rank: Frequent Contributor
timestamp: October 31, 2012, 11:58:17 am
content: Quote from: Rerouter on October 30, 2012, 01:51:59 amThat must be the reason why old gear is so über f*ckin expensive in Germany.Example:Davesuggestedthat the Agilent 3478A is a good bench meter to get and someone said he just bought one for 180$. Well a quick check on German Ebay revealed a single 3478A meter for the price of 399€.Cheers,Florian