Quadtech 1659 RLC DigiBridge project - Page 1
Forum section: electronics / testgear

author: DavidAzulay5000
author_rank: Regular Contributor
timestamp: January 21, 2023, 05:07:00 am
content: Quadtech 1659 RLC DigiBridge projectreconstructioncalibrationimprovementpaint jobTurned from a device when I purchased it at the time into something that looks like it came out of the trashA beautiful pearl that is accurate in every measurement

author: DavidAzulay5000
author_rank: Regular Contributor
timestamp: January 21, 2023, 05:08:28 am
content: more photos

author: DavidAzulay5000
author_rank: Regular Contributor
timestamp: January 21, 2023, 05:10:17 am
content: and more photos

author: DavidAzulay5000
author_rank: Regular Contributor
timestamp: January 21, 2023, 05:13:40 am
content: and more photos

author: DavidAzulay5000
author_rank: Regular Contributor
timestamp: January 21, 2023, 05:15:39 am
content: and more photos

author: DavidAzulay5000
author_rank: Regular Contributor
timestamp: January 21, 2023, 05:17:21 am
content: and more photos

author: DavidAzulay5000
author_rank: Regular Contributor
timestamp: January 21, 2023, 05:22:18 am
content: and more photos

author: DavidAzulay5000
author_rank: Regular Contributor
timestamp: January 21, 2023, 05:54:55 am
content: more main board photos

author: DavidAzulay5000
author_rank: Regular Contributor
timestamp: January 21, 2023, 06:07:47 am
content: and more photos

author: Bansci
author_rank: Contributor
timestamp: January 21, 2023, 08:49:04 am
content: Nice! Is that second to last photo a high power bridge rectifier? Looks massive for the system

author: DavidAzulay5000
author_rank: Regular Contributor
timestamp: January 21, 2023, 09:19:41 am
content: YESthe psu is a SMPI rebuilt the power supply.I made a lot of changes to the circuitIn order to give as clean a voltage as possible to the main board.I made dozens of changes to 1659As it is accurate at the level of metrological equipment.I do a lot of projects on improving and calibrating measuring equipmentand designand build measuring equipment.If I have the muse in the future I will post more postsI'm too lazy to upload photos here because you can only upload 10 photos at a timeFor each of my projects I take hundreds of photos of the electrical circuitsI usually post my projects only on my facebookMy profile is privateSo those who are not on my friends list cannot see them

author: precaud
author_rank: Frequent Contributor
timestamp: January 21, 2023, 02:04:33 pm
content: I think more pictures are needed, there's still remaining bandwidth to be consumed...

author: mawyatt
author_rank: Super Contributor
timestamp: January 21, 2023, 03:20:58 pm
content: Nice restoration work!! The Tek input hybrid reminds of our repair!Best,

author: DavidAzulay5000
author_rank: Regular Contributor
timestamp: January 21, 2023, 03:36:17 pm
content: Quote from: mawyatt on January 21, 2023, 03:20:58 pmI have 3 oscilloscopesof TEK2 of 2445and 1 of 2465I got all three brokenAnd I fixed and calibrated them allOn Facebook I have over 500 photos on the project about them

author: mawyatt
author_rank: Super Contributor
timestamp: January 21, 2023, 04:52:22 pm
content: We did same for our pair of 2465. Fixed defective hybrids, bad waveform cal source, recapped everything, clean up and so on. Nice analog scopes!!Best,

author: DavidAzulay5000
author_rank: Regular Contributor
timestamp: January 21, 2023, 05:22:32 pm
content: Quote from: mawyatt on January 21, 2023, 04:52:22 pmme tooI did a full capacitor recapAnd in one of them defective hybrids replaced In the picture with the red arrow2 were completely repaired and the thirdNeed to replace the A5 boardBasically the story started with a friend giving me the 2465 as a giftTo fix it, I bought a cheap 2445 for 70$for the parts.After I fixed the 2465I couldn't not give 2445 a chance to come back to lifeSo I bought a cheap 2445 for 60$I fixed the 2445 .Then I wasn't able to it to give the third 2445 a chanceSo I also completely repaired it, only it has the original defective hybrids from the first projectNeeds replacement.And an A5 board that needs replacementIn the future I will bring him back to lifeBecause I have no intention of purchasing another 2445I am not able to take advantage this amazing equipment just as an organ donorI bought most of my measuring equipment brokenand fix and calibrate them.In Israel, old measuring equipment is very cheapI will probably later buy the Agilent HP 83732B 10MHz to 20GHz Synthesized Signal Generatorthat he can sell it to me for less than 1000 dollars

author: Vgkid
author_rank: Super Contributor
timestamp: January 21, 2023, 06:34:38 pm
content: Nice job on the 1659 repair. Looks like that psu took some damage. My older 1658 , and newer 1689 both use a conventional transformer linear supply.

author: DavidAzulay5000
author_rank: Regular Contributor
timestamp: January 22, 2023, 10:38:58 am
content: Quote from: Vgkid on January 21, 2023, 06:34:38 pm1giga ohm test and more

author: jonpaul
author_rank: Super Contributor
timestamp: January 22, 2023, 10:49:17 am
content: Bravo, great job. Wonderful machine,My original 1659 GenRad is working OK but loud fan and the keypad decal gone.Only quirks...1/ Keypad decal often lost or damaged....Would love to get a keypad decal/overlay as you have made.2/ The leaded component test connector needs a lead/4 wire/BNC adapter, they exist byt rare.I would have added 4 floating BNCs to the front to replace the test connectors for use with ext 4 wire leads or tweezers.Jon

author: DavidAzulay5000
author_rank: Regular Contributor
timestamp: January 22, 2023, 10:56:17 am
content: Quote from: jonpaul on January 22, 2023, 10:49:17 ami know leaded component test connector is super rare

author: tplayne
author_rank: Newbie
timestamp: February 03, 2024, 05:41:14 am
content: Sorry for the necro-post. I recently came into one of these for myself. Admittedly it is the older body style, and branded as Genrad. Date codes seem to indicate a 1984 model year but it seems totally functional. It was so odd. When I got it it seems like someone had gone through and purposely messed up all the calibrations. Up to and including setting the frequency calibration to say that because after I did a very rough calibration using what I had on hand,

author: tplayne
author_rank: Newbie
timestamp: February 03, 2024, 05:54:09 am
content: Sorry for the necro-post. I recently came into one of these for myself. Admittedly it is the older body style, and branded as Genrad. Date codes seem to indicate a 1984 model year but it seems pretty much functional. It was so odd. When I got it it seems like someone had gone through and purposely messed up all the calibrations. Up to and including setting the base frequency calibration to zero.... somehow. When I got the device it selfchecked fine up to a "range 4 out of cal error" . After I did a very rough calibration using what I had on hand, (decade box, fluke 8842a and a scope) I was able to follow the service manual for frequency and range calibration for all 4 ranges and clear the range 4 error. Now I get range 3 out of spec but the measurement is pretty reasonable, based on my current gear.How did you go about calibrating you very pretty rebuild? Did you use highend trimmed resistors, or just a decade box and a very accurate multimeter?If I wanted to increase the accuracy I know I would need to get my hands on some metrology grade resistors of the specific values (the IET Labs official kit is out of my range). Any thoughts on where I could acquire such resistors. Ideally they would also specify the Q values. Usually I feel that "close is good enough", but knowing what this device is capable of, makes me really want to dial it in.-Tom

author: jonpaul
author_rank: Super Contributor
timestamp: February 03, 2024, 11:00:39 am
content: Hello: Havwe two 1689 later version of 1659, remarkable units.Go IET /GenRad site, DL full PDF of 1659 manual.Complete on use, performance check, repair calibration.https://www.ietlabs.com/1689.htmlUsually the 3.0V Lithium RAM backup battery must be replaced first.Turn on Self check 2222 x means CAL constants lostGenRad specifies a certain set or 4 VERY precice CAL resistors ($2000!) eg 24.7500 Ohms WITH SPECIFIC Q VALUES IN PPM.With a 6.5 or beeter DVM you CAN get the reiositances required BUT need a precce RLC bridge at 1 kHz to get the exact Q in PPM.See more info on forum for Metrology.Bon ChanceJon

author: SoundTech-LG
author_rank: Frequent Contributor
timestamp: June 07, 2024, 03:36:50 am
content: Hi Jon,I just got a hold of my 2nd 1689 as well! A complete CAL kit with case too (unused) for some odd reason the OPEN was wired as a SHORT, a mis-labeling issue.I recently had a problem in the 222 4 error, but it was a Freq CAL issue, and now resolved.Both 1689's full CAL'd except the for the Frequency Correction K Factor Procedure, which looks a bit daunting.Nice both of them now agree on measuring the Cal Kit values.Never seen aftermarket Tektronix blue on GR equipment. I think I will reserve my paint for Tektronix gear.Not so sure I like GR baby *hit yellow either.