FS QuadTech 1659 - Page 1
Forum section: electronics / general

author: itsbiodiversity
author_rank: Regular Contributor
timestamp: January 05, 2021, 12:47:03 pm
content: I have a QuadTech 1659 LCR Meter purchased at auction. The meter appears to have some errors, but is in great physical condition and does conduct measurements. If anyone is interested in taking the project over let me know. I paid around $300 and will entertain offers starting there (if there are any). Also, if anyone wants to help me get this beauty in mint measuring condition feel free to offer your services!

author: itsbiodiversity
author_rank: Regular Contributor
timestamp: January 05, 2021, 01:10:12 pm
content: Error appears to be signal strength related. Possible charged capacitor protective fuse blown?

author: bob91343
author_rank: Super Contributor
timestamp: January 05, 2021, 10:58:58 pm
content: I have a 1658 that I have repaired twice. In both cases there were failed protection diodes, perhaps caused by applying voltage to the input leads. Find those on the diagram, near the input terminals.I only paid $75 for mine in good working condition. But that was a long time ago. It's an amazing instrument and very accurate. Principle of operation rather sophisticated, and all measurements are compared to one resistor standard.

author: itsbiodiversity
author_rank: Regular Contributor
timestamp: January 06, 2021, 12:24:30 am
content: The diagram I have is extremely tough to see - you wouldn't happen to have a snippet of that would you? I have a 1657 that is beat up and not as pretty but it still measures all of my calibrated standards almost PERFECT. Was it a difficult replacement? Also - would you replace the diode, sell, or return to seller? Trying to figure out the best coarse of action, but I had 23 other bids until the last moment even at this price so I am sure there are a niche buyer out there. Even for parts they're worth around what I'm asking/paid. Thanks for your input - very appreciated!

author: bob91343
author_rank: Super Contributor
timestamp: January 06, 2021, 08:00:40 pm
content: I don't know about the 1659 but the entire manual for the 1658 is available online. It should be fairly close.The diodes are easy. Of course I don't know if that's what your unit needs.I would love to have yours but the price is too high for me.I also have a 1650A which has the advantage of making resistance measurements at dc, which our units will not. I also have a 1644 which very useful for extremely high resistance as well as reforming electrolytic capacitors. My most accurate ohmmeter is an HP 3456A.Incidentally do you have any test fixtures for your unit? I made one up and it's great because it enables four wire measurements. I haven't been able to make the bias work, however.

author: itsbiodiversity
author_rank: Regular Contributor
timestamp: January 06, 2021, 11:25:58 pm
content: The test fixture I have (I believe is a 1657 or 1659??) is a four wire plus ground attachment. It is great with my functional 1657. Sadly this one will probably be returned.

author: bob91343
author_rank: Super Contributor
timestamp: January 07, 2021, 05:36:11 am
content: Yes that's the fixture I built. Works great although now and then I have to resolder the leads.