Electronics > Repair

Datron 1030D RMS Voltmeter

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telectric:
I've been working on a Datron 1030D RMS voltmeter for a while now and am getting no where trying to trace out the design.  I have looked high and low for a service manual for this model but have not found one.  While the 1041 has some similar circuits the assembly drawing with the component reference designation is completely different.
So if someone has a 1030 manual and would like to make a  copy or sell the manual I'd be willing to pay a reasonable price plus shipping.  Or better yet if someone knows where to find a scanned copy and can point me to the download location I'd be one grateful & happy camper.

Thanks

Gyro:
Damn, I can't keep my head down any longer.

I have a bunch of vintage Datron kit, a 1041, 45, 51, and a 1030A. I was the one who scanned the 1041 and 1051 manuals on KO4BB... with the help of a fellow 1051 owning member, who stiched the schematics and straightened the pages for me.

I have the 1030 Manual, the component layout matches my 1030A (the original 1030 was a slightly less polished layout). I have no idea what the differences are with the 1030D (or presumably 1030C), presumably they are later tweaked versions.

The A/D / display PCB is identical to the one on the 1041, just depopulated for the lesser requirement (in fact, add one ttl counter chip and cut a link and you get the enhanced resolution 4 1/2 digit option.

The problem is that the 1030 is very well documented, ie. a lot of pages, schematics larger than A4 etc. I knew ought to scan and upload it at some point but wasn't looking forward to it. You'll probably need to give me a couple of weeks to do it.

Is there anything specific that you're looking for immediately, or a specific fault? I can take a couple of snaps with the camera if so.

telectric:
Chris,

Thanks for the reply.  I came across most all your posts in the EEVblog but not much on the 1030x.  A couple of discussions, one with some one generous enough offering to give two away and another discussions but no mention of where to get a manual for the 1030 series. I did download the 1041/1051 manual from KO4BB boat anchor site.  Thanks to you and the person who helped you for all the effort to get it out there.

Right now all that's displayed is a decimal point which will follow the selected range.  Occasionally all decimal points show up and even less frequent I'll have some digits when first turned on. Either of these two will stay until a range button change. Then back to one decimal.  I disconnected the input wires from the back of the front binding post so I could check that the flat cable connector was OK.  Lucky I did this because I found a pin folded over. Correcting this didn't help fix the other problem(s).

I have checked the power supplies and have done some input tracing through the front end of the AC board, checked that the relays are switching and contact is being made in each of the positions. I've not done any verification if there's any voltage drop across the contacts but I'm don't think this matters to much at this time. If needed I'll clean the contacts once I have the unit working. This is about as far as I've gotten.

I'll get back to it one night this coming week and use the 1041/1051 schematic and hope the test points match the 1030D.  If they do then this will help considerably.

A photo of the 1030D AC board is below so if it comes close to matching that in the 1030 manual you have then I'd appreciate a quick snapshot showing the component reference designations.  I am in no hurry for a complete manual but would like to have one sometime if you do get around to scanning it in. I'd be happy to contribute to the effort in any way that would help.

Thanks again for responding and your offer to help. It's really appreciated.

Tracy

"And your name is..."

Gyro:
Hi Tracy,

Glad to be of help.

That looks in very nice condition internally. It looks like one of the later "Datron Instruments Limited" front panel Logo ones (earlier ones just said "Datron"). From the size of the grey capacitors and the manual, I've figured out the 1030D bit. The D refers to the filter combinations. The 'D' configuration has minimum frequency of 10Hz (normal) and 0.1Hz (LF mode). You will probably want to change it to the Default 'A' configuration at some point (40Hz/1Hz) as it significantly improves settling time (the options are all in the manual anyway). Despite their age, these meters have really good specs and are very useful. Nice Panaplex displays too.

Firstly, treat all Tant bead capacitors (particularly the ones near the regulators on the A/D board) with extreme caution, I've had several fail. Replace with higher voltage ones at the first opportunity. Failed tants can also cause all sorts of fault symptoms if they pull down the +/-15V rails (or leak too much), finger check the temperatures of the relevant strip metal heatsinks.

The other thing to remember is that with these Datrons, overload is denoted by the display blanking, so apparent display problems can be nothing more than out of range input (particularly with the DC high impedance models). I worked out an easy mod for this, to give the more common +/- leading 1 on overrange. Just add a diode (1N4148 is fine) between  M9, pin 6 (anode), and M15, pin 8 (cathode), no track cuts needed. It might just be worth adding this as a diagnostic measure anyway. The 'sig'  pin on the A/D board is expecting a 1V scaled input voltage (max 1.999V), so if that isn't happening, the display will blank otherwise.

I've attached photos of the board idents and schematics, hopefully readable enough to get you going. The decimal point issue ought to be fairly trivial to trace, as you found, issues with the ribbon cable can cause issues. The switches are normally very reliable and actual functions on the board are JFET switched rather than relying on contact resistances. You'll see that the A/D board is a part loaded 1041 (and 1045) board - it doesn't need to handle negative inputs, no autoranging etc.

I hope this gets you started. I've just remembered that the manual is ring bound which will make scanning a bit easier.

Chris.


P.S. I've had to compress the images a bit to fit. They still look readable but if you want the full res ones, I've uploaded them to uploadfiles.io https://ufile.io/i3wq2onk available for 30 days. No need to create an account, just use the free download option.  :)

telectric:
Chris,

Perfect!!  That's exactly what I needed.  I did download the high res shots and then cleaned them up with some changes in brightness and contrast using GIMP.  They came out fantastic once printed. Even on letter size paper I can see everything clearly. Nice job of taking the photographs.

I'll start t-shooting again in the next day or so and feel pretty confident (famous last words) that I can get this 1030 back in good health.  I have read a lot of good things about the Datron meters and that's why I picked this one up.  Plus I just don't have enough meters as it is, ha ha.

I'll implement your tips and mods once I have it working.  They seem very worthwhile. BTW do you work or did you work for Datron?  You appear to be at guru if not wizard status with all that you know about these meters.  Just curious!

Not only is it clean on the inside the outside it in really excellent condition as well. It's going to be a nice addition to one of my benches.

I'll post what I come across and what the root cause was as I go along.

Thanks again for your help.

Tracy

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