Quadtech 1659 RLC DigiBridge project

[DavidAzulay5000]

Quadtech 1659 RLC DigiBridge project

reconstruction
calibration
improvement
paint job
Turned from a device when I purchased it at the time into something that looks like it came out of the trash
A beautiful pearl that is accurate in every measurement

[DavidAzulay5000]

more photos

[DavidAzulay5000]

and more photos

[DavidAzulay5000]

and more photos

[DavidAzulay5000]

and more photos

[DavidAzulay5000]

and more photos

[DavidAzulay5000]

and more photos

[DavidAzulay5000]

more main board photos

[DavidAzulay5000]

and more photos

[Bansci]

Nice! Is that second to last photo a high power bridge rectifier? Looks massive for the system

[DavidAzulay5000]

YES
the psu is a SMP 
I rebuilt the power supply.
I made a lot of changes to the circuit
In order to give as clean a voltage as possible to the main board.
I made dozens of changes to 1659
As it is accurate at the level of metrological equipment.
I do a lot of projects on improving and calibrating measuring equipment
and design
and build measuring equipment.
If I have the muse in the future I will post more posts
I'm too lazy to upload photos here because you can only upload 10 photos at a time
For each of my projects I take hundreds of photos of the electrical circuits
I usually post my projects only on my facebook
My profile is private
So those who are not on my friends list cannot see them

[precaud]

I think more pictures are needed, there's still remaining bandwidth to be consumed...

[DavidAzulay5000]

 

[mawyatt]

Nice restoration work!! The Tek input hybrid reminds of our repair!

Best,

[DavidAzulay5000]

Nice restoration work!! The Tek input hybrid reminds of our repair!

Best,

I have 3 oscilloscopes
of TEK
2 of 2445
and 1 of 2465
I got all three broken
And I fixed and calibrated them all
On Facebook I have over 500 photos on the project about them

[mawyatt]

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,

[DavidAzulay5000]

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,

me too
I did a full capacitor recap
And in one of them defective hybrids replaced In the picture with the red arrow

2 were completely repaired and the third
Need to replace the A5 board
Basically the story started with a friend giving me the 2465 as a gift
To fix it, I bought a cheap 2445 for 70$
for the parts.
After I fixed the 2465
I couldn't not give 2445 a chance to come back to life
So I bought a cheap 2445 for 60$
I fixed the 2445 .
Then I wasn't able to it to give the third 2445 a chance
So I also completely repaired it, only it has the original defective hybrids from the first project
Needs replacement.
And an A5 board that needs replacement
In the future I will bring him back to life
Because I have no intention of purchasing another 2445
I am not able to take advantage this amazing equipment just as an organ donor

I bought most of my measuring equipment broken
and fix and calibrate them.
In Israel, old measuring equipment is very cheap
I will probably later buy the Agilent HP 83732B 10MHz to 20GHz Synthesized Signal Generator
that he can sell it to me for less than 1000 dollars

[Vgkid]

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.

[DavidAzulay5000]

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.

1giga ohm test and more

[jonpaul]

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

[DavidAzulay5000]

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

i know leaded component test connector is super rare

[tplayne]

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,

[tplayne]

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

[jonpaul]

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.html

Usually the 3.0V Lithium RAM backup battery must be replaced first.

Turn on Self check 2222 x means CAL constants lost


GenRad 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 Chance


Jon

[SoundTech-LG]

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.