Datron Wavetek 4950 Transfer Standard Finishing Touches & Tests

00:00 Intro
00:53 Self test
01:37 ACV pre-preamp
03:59 Current assembly
04:48 Input connector
09:54 Worn out relay
11:17 Cal setup
13:30 Calibration test
14:59 ACV linearity
21:10 Special menu
22:14 DCV linearity
23:07 DCV noise

[frikkied]

The ratio of how much I enjoy this vs how much I understand is off the charts

[madnessandescapism]

You definitely need to try black magic. I mean microwave stuff, that would be extremely interesting.

[killsalot]

this guys sense of humor makes every vid a 10

[IanScottJohnston]

Noticed the roll of paper towels, handy for mopping up escaping luckily Mr. Reps didn't need many, he caged them back up safely.

[lbgstzockt]

I would love to see you do some RF stuff, it contains even more magic than nanovolts. Plus you often play with nanovolts, disguised as dB.

[JTL-DK]

I have no clue on what all this stuff is for, but i love your dry German humor and your technical explanation and your curiosity and that you like me take everything apart to see what makes it tick...
My big question is what do you actually use all this equipment for?
I know what ppm and a lot of the technical terms since i am en electritian and a ventilation technician, but still a lot of this stuff is way over my head 😀

[Orbis]

Thanks a lot for this "wetting current" hint. This might be the problem why those super expensive hermetically sealed relays on the voltage sense card (ADC) in the semiconductor test stations I'm going to work on are failing... "even there is literally no current flowing through them"... :)

[Gefionius]

I still can’t believe your sense of humor in not your mother tongue. Love it!

[goober-llwx]

Does anyone else watch these videos and have zero clue what he's talking about, but is still fascinated...

[alexscarbro]

Check out Raymark labelling material for front panels. It’s a kind of polyester like backing with an uncured epoxy coating. It comes in label or A4 uncut sheets. You print on it with an inkjet and then bake it in an oven. The baked sheets are resistant to oils, solvents, fuels and quite wear resistant!

[MCsCreations]

Pretty impressive equipment indeed, Marco! 😃
Fantastic work fixing it!
Stay safe there with your family! 🖖😊

[pauldorman]

Excellent repair and modifications. Always wonderful to see a fine instrument given another lease on life. Also, that's a lovely $1700 torque gauge you have there!

No resentment from me, but I see way too many awesome looking tools made from unaffordium on YouTube.

[johantoftling]

I have to say I am jealous on you, to have the ability to dive so deep and sort things out. I have been fighting for more than a year to fix my oscillator in my Fluke 5100B without success. Thanks for a great video.
Happy new year 🎆

[randynovick]

I love this content. I have a feeling that given an ossified claw from a T-Rex you could make it walk and talk and feed on small children like back in the good old days. Thank you for this work, and for sharing it.

[Oysteims]

PVDF heatshrink + PVDF cables (SPEC-44/MIL-W-81044) make a very good pairing. The heat shrink fuses with the cable jacket and forms a perfect bond when using the right temperature, giving you up to 2, 5kV voltage rating, as well as all the excellent properties associated with PVDF. Just unfortunate that the HV type can get very pricy per meter, but the 600V rated one is decently priced.

[K.D.Fischer_HEPHY]

21:37 - Sir, you are the real treasure in my mind. 👍

[wolpumba]

*Overview*
- Marco Reps discusses the Datron Wavetek 4950, a multi-function transfer standard, detailing its issues, repairs, and tests.

*Repairs and Issues*
- Fixed a missing positive voltage supply rail on the analog board.
- Replaced a damaged op-amp in the AC millivolt pre-pre-amp.
- Addressed leakage current issues in the current assembly.
- Replaced the original front input connector with a more universal one.
- Replaced a worn-out relay affecting the AC attenuator and preamp board.

*Modifications*
- Created a new sheet metal holder for the front input connector.
- Used PTFE heat shrink tubing to add dielectric strength.

*Calibration and Testing*
- Used a Python script to calibrate the Datron Wavetek 4950 against a Fluke 5700 calibrator.
- Found some discrepancies in ACV linearity.
- Used thermal voltage converters to validate ACV linearity.

*Additional Features and Observations*
- Found that the Datron Wavetek 4950 has excellent DCV linearity and low noise.
- The device uses hermetic bulk metal foil resistors for stability.

*Conclusion*
- Marco is impressed with the Datron Wavetek 4950's performance and is glad it was saved from being discarded.



*Positive Points*
1. *Excellent DCV Linearity:* The Datron Wavetek 4950 shows remarkable DCV linearity, exceeding expectations for a seven-and-a-half-digit class device.
2. *Low Noise:* The device has low noise performance, even down to the least significant digit.
3. *Stability:* Uses hermetic bulk metal foil resistors for stability, making it reliable for its primary function as a multi-function transfer standard.
4. *Versatility:* The device can be modified to act like a normal multimeter, adding to its utility.
5. *Durability:* Built with quality components that guarantee long-term stability.
6. *No Cooling Fan:* Lacks a cooling fan, which is seen as a positive due to the longer time constant and low temperature coefficient.

*Negative Points*
1. *ACV Linearity Issues:* Some discrepancies were found in the AC Voltage linearity during testing.
2. *Complex Repairs:* Multiple issues required attention, including replacing worn-out relays and fixing leakage currents.
3. *Limited Documentation:* Lack of comprehensive service manual makes some advanced adjustments risky.
4. *Old Connectors:* The device uses older types of connectors, requiring adapters or replacements for modern setups.
5. *Settling Time:* Thermal voltage converters used for testing have a long settling time, making the calibration process lengthy.

These points are sorted by their impact on the device's performance and usability.

[tnts]

I remember you as a child - you designed JBC clone soldering iron - that was cute

[KCIEQ]

Outstanding! Just a note, at 16.50 you reference the 874 "General Electric" connector- It is General Radio, not General Electric. (Here we just call it a "GR" or "GenRad" connector. :)

[Stuartrusty]

Yes, finally. Fame at last. Fluke Norwich is my workplace. We have many treasures indeed, including most of the guys who were there in the Datron days. More than that, I'm not permitted to