Boat-anchor joys - HP3497A with DVM option 001 - Page 1
Forum section: electronics / testgear

author: trobbins
author_rank: Frequent Contributor
timestamp: September 01, 2019, 03:38:23 am
content: This HP3497A had a self-test '2' error, and the DVM just sat at 0.00002V. Luckily it was just one of the doubler supply rails with a bad electrolytic, and now back to normal operation. The power supply board showed previous replacement of an electrolytic in the other doubler rail, and a stressed resistor. Much more pleasant to faultfind power supply sections than all the other logic and control circuitry in this beast, as that seems to require an extender board and logic analyser if one starts to follow the faultfinding guide to progress through the procedure for '2' error code.Anyway, for almost zero dollars, I am finding the 5 1/5 digit voltmeter to be a great round-robin voltmeter for my other minimal benchmeters, of which it is on a par with my Keithley 197 for DCV.And the accompanying current sources provide a nice resistance measurement reference with better than 0.01% accuracy, and no sign of age showing up when checking RC55 0.1% resistors (best I have on hand).The other use I will try for this boat-anchor is its > 10 gigohm input impedance for up to 12VDC range (for valve preamp grid-leak bias testing), which is an order of magnitude better than the Keithley that only provides high impedance up to 2VFS.So not easy to fit on the bench, but can be worthwhile having available for almost no cost.

author: Inconel-oh-el
author_rank: Contributor
timestamp: September 01, 2019, 06:10:16 am
content: (Lurker emerging from the woodwork)I recently picked one of these up as well, despite an utter lack of need for it.I had walked past it a few times at my University Surplus store, and only upon finding out that it has an intrrmal 5 ½ digit DMM did I make the impulse decision to pick it up. Mine seems to work fine, passes the self test, only issue is that the buttons are a little too clicky.Like a few others have posted before, when searching eBay for more optional modules I realized that most sellers pull out just the terminal blocks, leaving the actual module PCB 's in the machine, then list the connector as the whole deal.Turns out I made the same mistake, as I discovered upon further inspection that mine included 3 (!) of the 20 ch. multiplexers. Picked up a few of the terminal blocks for cheap, but again I have zero use for equipment this big, or 60 channels of anything that need monitoring.The DMM is pretty sweet though, and entering commands then hitting execute to watch the display whirl away is so extremely satisfying. Would love to get a gpib adapter to play around with computer controlling it.

author: trobbins
author_rank: Frequent Contributor
timestamp: September 01, 2019, 09:06:15 am
content: Yeh mine has a complete option 110 and 010, but also 2 more relay mux acquisition boards without the header modules.I also don't have a GPIB control and interface setup, so that wasn't an aim for me, and if any aussie researcher needs those mux boards/modules then I'd happily pass them on. The DVM was the principal interest.

author: Inconel-oh-el
author_rank: Contributor
timestamp: September 01, 2019, 10:58:25 pm
content: I am super impressed with the fact that mine still reads dead on, having done zero calibration. My scope is probably the best voltage reference I have at the moment, I've checked it against a 34401a at school, it was pretty damn close. Measuring with the 3457a showed 4.9998 V. It was just a quick measurement, probably could have let them warm up longer but ain't nobody got time for that.I've ordered a 5v reference IC that hopefully I can characterize for longer at the school's lab then check at home. If I had a GPIB interface plotting that data would be fun, but those cut a little too far into my beer fund.