Author Topic: Datron 4000A getting at test points?? (Read 22452 times)

branadic · « **Reply #125 on:** April 20, 2019, 07:04:31 am »

Thanks for the congrats. No, a solder stencil won't work as the circles in "d", "B" and "%" as well as the triangle in the "A" would be missing. Thus I think the film glued to a spacer with adhesive spray is the best and economical way to make the mask. It is light-thight and reflects all details.

I don't think the dim digit is because of resistor values as it moves depending on the settings. Need to dig into that.

So now I need to wait for the new boards to arrive as well as the film and the switches.

By the way, this is exactly what I was looking for: https://www.toppress-siebdruck.de/de/leistungen/diffusorfolien.html

-branadic-

maginnovision · « **Reply #126 on:** April 20, 2019, 04:17:14 pm »

Quote from: branadic on April 20, 2019, 07:04:31 am

Thanks for the congrats. No, a solder stencil won't work as the circles in "d", "B" and "%" as well as the triangle in the "A" would be missing. Thus I think the film glued to a spacer with adhesive spray is the best and economical way to make the mask. It is light-thight and reflects all details.

I don't think the dim digit is because of resistor values as it moves depending on the settings. Need to dig into that.

So now I need to wait for the new boards to arrive as well as the film and the switches.

By the way, this is exactly what I was looking for: https://www.toppress-siebdruck.de/de/leistungen/diffusorfolien.html

-branadic-

You're not kidding, that is literally what you needed. With that the spacer will be much more reliable allowing you to just have holes for the small designators. They even have your pcb on the home page, haha. Hopefully that dim digit issue isn't a huge time sink.

branadic · « **Reply #127 on:** April 21, 2019, 10:31:43 am »

Can someone with Datron 4000A please post a picture how the binding posts are mounted to the front panel? I have a unit with the binding posts one the back, simply putting them to the front doesn't work as the holes in the front panel are to big. Is there an additional board the binding posts are mounted to? I pretty much appreciate any support as I like to have the binding posts on the front of the unit. Thank you very much.

-branadic-

Johnny10 · « **Reply #128 on:** April 21, 2019, 11:58:29 am »

Simply mounted to front panel.

branadic · « **Reply #129 on:** April 21, 2019, 12:21:03 pm »

That doesn't work for me. The holes in my front panel (Datron 4000A) are 0,7 inches in diameter, while the plastic washers of the binding posts are only 0,6 inches. The drill holes on the picture you uploaded are much smaller. So at some point the may have changed the front binding post mounting like having an extra pcb, since the holes in my unit are original, visible by the nickel coating also on the walls of the holes and there is a Datron sticker above the front terminal holes saying "Rear Output".

-branadic-

essele · « **Reply #130 on:** April 21, 2019, 12:32:13 pm »

My 4000A is exactly the same as the picture, mounted directly onto the front panel.

I've actually got a rear terminal 4200 hopefully arriving on Tuesday (glutton for punishment), so I can see what holes are beneath the panel once it arrives.

Johnny10 · « **Reply #131 on:** April 21, 2019, 12:39:54 pm »

Page 38 of Service manual shows a shoulder on the plastic part of post.

branadic · « **Reply #132 on:** April 21, 2019, 01:19:29 pm »

See the difference?

-branadic-

Johnny10 · « **Reply #133 on:** April 21, 2019, 03:13:29 pm »

You know I have always wondered what the 4 screw inserts were for on the mainframe of the Datron.
Just behind the input posts.

Those holes are sized to go around input jacks.
The 4 screw holes are for mounting a board.
With input jacks attached.

I imagine in a similar way to Datron 1062 DMM input posts.

Johnny10 · « **Reply #134 on:** April 21, 2019, 03:37:51 pm »

Your type Terminal Board can be found in the Datron 4708 Service Manual

Layout Drawing Number 480640-1.2 Sheet 1 Datron Instr. 1989

Comes up as Page 428 on my PDF Viewer

maginnovision · « **Reply #135 on:** April 21, 2019, 03:56:21 pm »

From my 4000.

maginnovision · « **Reply #136 on:** April 21, 2019, 03:58:19 pm »

Two more of the input board.

Johnny10 · « **Reply #137 on:** April 21, 2019, 04:11:06 pm »

Gonna be a lot of sore backs tonight from hefting around the Datron 4000 units !

branadic · « **Reply #138 on:** April 21, 2019, 04:29:37 pm »

Thanks, that's what I was expecting to see. So I simly need to use a FR4 board with the proper drills and a steel sheet with the proper drills and painted black to make a poor man's front panel mounting. The wires on my unit are soldered to the binding post, so no real need to reproduce the board.

-branadic-

essele · « **Reply #139 on:** April 23, 2019, 07:53:47 pm »

Just for completeness, this is the front panel of my new rear-terminal 4200 ... you can see the smaller holes, so hopefully this will be an easy rework.

essele · « **Reply #140 on:** April 25, 2019, 06:09:56 pm »

Interestingly I've just opened up my original 4200 and it seems to have the cut-outs the same as yours branadic, with the terminals mounted on an internal board.

It is actually a bit easier to work with since you can remove the front panel more easily ... although obviously makes the move from rear terminals to front terminals a bit tougher.

branadic · « **Reply #141 on:** April 25, 2019, 06:30:34 pm »

Thanks, I will think about how to solve this, the simple way or the professional way (reproducing the board as shown on the pictures).

BTW: Got mail this morning, the new display boards are on their way, so they should receive within the next two weeks. The repro film print should receive within the next days and I also had a phone call with toppress-siebdruck today and should get an offer for 10 prints tomorrow?
The redesigned plastic covers are also in production, this time using FDM printer with white filament instead of DLP printer. So the calibrator will be in working condition for the metrology meeting in june, except that I won't get it adjusted.
A propos adjusted, anyone out there with experience on this? As far as I know Mickle T. got his Datron 4000A calibrated to linearity <0.1ppm. I already contacted him and asked him to share his experience on that, but he seems to be offline on this board for quite some time

-branadic-

maginnovision · « **Reply #142 on:** April 25, 2019, 06:42:52 pm »

The calibration routines are not terribly complicated but you need another source and a null detector. I faked it by using a meter since the Prema has <20pA bias but a 335D should allow you to do most of everything. The linearity is just adjusting 10V FS vs 10V. I thought about getting one but I don't really want to spend the money for just this. I got a quote for 1K for Cal(w/adjust) but he needs to talk to the lab to make sure they're still capable as they haven't done one in years.

branadic · « **Reply #143 on:** April 25, 2019, 06:51:30 pm »

So if I get you right I could use one of my LTZ1000 with 10V +/-0.1% and a calibrated meter such as 3458A or K2002 to adjust FS?

-branadic-

maginnovision · « **Reply #144 on:** April 25, 2019, 07:00:19 pm »

Just measure the voltage, you don't actually apply anything. They specify a lot of expensive gear but if you don't mind a small offset due to bias current I think it's ok.. You just set it to output voltages and enter in the actual value. Linearity says you should clear all memories though so need linearity, coarse gain then standard Cal of setting zero, trimming 10V ref then calibrate individual ranges. If I had access to those I would do Cal using both meters to get it as close as possible.

essele · « **Reply #145 on:** April 25, 2019, 08:25:38 pm »

Nobody in the UK seems to want to reply to my messages about a 4000A or 4200 calibration.

For the 4000A would it work to hire a calibrated 3458A for a week, which looks to be available for a few hundred quid, and do it with that?

The 4200 seems like a more complicated beast.

maginnovision · « **Reply #146 on:** April 25, 2019, 09:13:25 pm »

Quote from: essele on April 25, 2019, 08:25:38 pm

Nobody in the UK seems to want to reply to my messages about a 4000A or 4200 calibration.

For the 4000A would it work to hire a calibrated 3458A for a week, which looks to be available for a few hundred quid, and do it with that?

The 4200 seems like a more complicated beast.

I think a good meter will get you very close. Once my 1082 comes I'll check it against my ltz1000s and if they're pretty close I'll use it to see how far my 4000 is from it and compare to Prema. A fluke 335 dialed in by a good meter would really would be a good tool for this but I don't personally think it'd be worth it. The offset due to bias current should be stable.

I had similar problem getting a response even to get a couple of datron 1062/72 calibrated. Most who responded said they didn't have the equipment.

Tektronix and simco were the only ones to offer a quote without saying they couldn't do it.

branadic · « **Reply #147 on:** April 26, 2019, 07:14:26 pm »

Received an offer for the printed light-scattering films today, the print is 15€ per display. The "real repro film" is only 18,50€ incl. shipping and includes prints for 8 displays. Mh... will wait to check their quality before I step forward to the more expensive but for sure higher quality solution.
Also received two FDM printed frames today. Hopefully the pcbs arrive soon.

By the way: I was interested in noise of the Datron 4000A so I measured low frequency noise today with output set to 10V.

-branadic-

maginnovision · « **Reply #148 on:** April 27, 2019, 05:34:21 am »

Looks pretty good. Was that after 4 hour warm up? I'm pretty excited to see how displays look. Did you ever figure out the dim digit issue?

branadic · « **Reply #149 on:** April 27, 2019, 08:02:55 am »

No, not 4h only half an hour, but the picture doesn't change between turning the unit on and half an hour later.
I'm also excited to see how the display turns out.
The dim digit is most likley due to timing settings from the controller and presumably wanted for the gas discharge display. Depending on the range choosen the dim digit changes position, but it's not a problem of my display board. I will change the resistors to overall higher current through the LEDs to make it a big brighter, there is still enough reserve. In the pictures shown I used the DLP printed frame with a printed paper on top that is fixed with polyimid tape. Doesn't look to bad by now.
By the way, I'm using Kingbright KPHM-1608SECK.

-branadic-


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Author Topic: Datron 4000A getting at test points?? (Read 22452 times)

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