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Dear tektronix fans

To introduce myself Hubert ON6JZ living in Belgium and an electronics repairer for 45 years
I now have a tektronix 2712 on the table that does not work.
It has been idle for over a year.
At startup it gave all kinds of error messages , after replacing both batteries on the digital board and on the digital option board it seems to start up normally ,
but I get no response from any button and the encoder does nothing either
All supply voltages are correct and viewed cleanly with a scope
I replaced all the smd electrolytics on the sweep board and on the digital storage board
No result
On the screen I get an image of out of memory.
Does anyone have any tips on where I can look for this error?

Thanks in advance

Hubert

If anyone is interested in old GPIB adapter hardware and has a USA mailing address, I can offer for free:

- HP 27209-60001 GPIB 8-bit ISA card, or

- IOTech Micro488/EX Bus Controller (this is a bi-directional RS232<-->GPIB gateway), w/power adapter and manual

Either (or both, if you can use both), would be for the cost of postage on a USPS flat-rate box. You would email me a label.

Either can be used to do the cal backup, and communicate with other GPIB/HPIB/IEEE-488 equipment. They're not doing anything here except collecting dust for years. Please contact me off-list if interested.

-mark

I run Linux with the linux-gpib driver, which from personal experience works fine with the NI GPIB PCI card and the Keysight 82357B.

For windows, I'm certain other users can jump in with some recommendations. Steve Hendrix, a user on this group, has a product called the KISS-488, but I have not used it: . There are a number of open source GPIB (aka IEEE-488) adapters, such as the AR-488, if you are looking for something more home-brew.

If you are asking specifically about the cable, I would recommend getting a used HP 10833A/B/C/D cable. They come in various lengths depending on the suffix letter.

Note that GPIB functionality is very limited on the 2445/2465 (plain)/A/B and 2467 scopes and only provides basic control and can also return measurement values. It does NOT allow you to download a copy of the displayed waveform, if you are expecting that. So, if you have a GPIB interface laying around, it's handy to use for calibration backup, but I probably wouldn't go out of my way to get one just for backup.

For the software on the PC, you just need to be able to send a command and capture the output to do a cal backup. All adapters have this capability in their host software. No one has written any special application for backing up these scopes, as far as I know.

-mark

On 2025-04-09 9:40 AM, Alex wrote:

I know there are those rather pricey HP GPIB to USB adapters floating around ebay for $100 and plus.

Well, my KISS-488 is one of those "pricey" adapters, at $129 single piece via my www.hxengineering.com, but it does way more than just USB. USB/serial at 115.2 KBPS, Telnet, HTTP (any standard browser), SNTP (sets a local clock, to timestamp data it records and graphs), ICMP (so you can ping to confirm connection), and TFTP (for firmware updates). And I've recently added some "quantity purchase" options as well. Best of all, it's as close to obsolescence-proof as I could make it - no PC side drivers to load, indeed not even tied to PC, as one of my beta testers uses it with an Apple. Just a lot of standard protocols that are well establish and not likely to go away soon. Others have suggested the roll-your-own approach, but I'm here to tell you it takes a lot more than it first appears, and I'll never make enough on it to justify the amount of time in it. But I mode it for my own use and decided to share it to help keep these old boat anchor precision instruments alive.

Pardon the sales pitch, but I only mention it when directly applicable to solve a list member's need. I'll shut up now, and any queries should be taken offline directly to me at SteveHx@....

Steve Hendrix

Yes, it also works with the 2465 (meaning not A or B versions).

With the 2445 or 2465, you will get 200 calibration values returned instead of 256. If you don't have any options installed, I believe it will only return 100 values because the second EEPROM (EAROM) resides on the options card cage which is only installed if you have options.

-mark

Just for completeness of the information, what kind of cable is needed to do the GPIB backup into a windows PC?
I know there are those rather pricey HP GPIB to USB adapters floating around ebay for $100 and plus.
Would that be the correct cable type?

And what software is needed in the PC?

On 8 Apr 2025 5:17 pm, Jean-Paul wrote:

Dale, Mia culpa on the TM faux pas....

Jean-Paul -

It is a far-too-frequent error. The patented precision track plating and wiper button design make the Variac significantly better than other brands that I have used.

If you have not seen it the patent, assigned by Smiley Gilbert to GR, is at:


--
Dale H. Cook, GR/HP/Tek Collector, Roanoke/Lynchburg, VA

Does this procedure also apply to 2465 ?
thanks.
maurizio

On Tue, Apr 8, 2025 at 05:10 PM, Jean-Paul wrote:

Better to get a replacement

Okay... but, where?

--
Roy Thistle

John,

Thanks for the information. I had not had the CRT problem - yet. There's always plenty of time for additional problems to accrue!

Not to be snarky, but did your filament transformer have at least a 5,000 Volt rating? I know that the CRT heater voltage is elevated quite a bit to prevent H-K breakdown, and that is why I have been saving just such a 6.3 Volt transformer for over thirty years.

As for my 310A troubles, I had wondered if the insulating varnish might be breaking down, although I have no transformer information or specifications that could confirm this by DC resistance readings of the windings.

The confounding thing is that this came on so suddenly and to both of my 310As to the point that I would put the heat theory in second place more because of the infrequency of use of both of these 'scopes. Perhaps, though, infrequent use was the cause of the trouble by leading to a high inrush current to form those damned electrolytic capacitors (I am gradually switching to film types where possible. ). I had blown a metal film 10 ohm resistor, R601, at the input of the -150 volt power supply two or three years ago and had attributed it to a poor choice of resistor type in that position in the circuit, but perhaps it was more than just the type. The carbon film types that I put in are still working.

Chuck Harris is the Tektronix HV transformers guru, on tekscopes2 only, due to,issues with tekscopes moderators

Ask Chuck, he may have tips but procedures is difficult and needs correct wire, insulation etc.

Better to get a replacement

J

Hi. I might have one of these. I will check.

Hi. I also have two 310A scopes. Both have had power transformer problems. On one the crt heater winding broke down and I had to add a small filament transformer for the crt filament. On the second one the same thing happened. However eventually the added transformer also broke down. It has some other problems with the other windings as well. I do have a spare 310A power transformer but don’t know its condition. I suspect these problems are due to excess heat. The 310 should really have had a fan. I don’t know what else could be causing such power transformer problems. I bought a flat fan designed for going under laptop computers but never really got to test it much. I would use that if I was using a 310 much. Sorry I can’t be more helpful.

I have two 310A 'scopes that were, if infrequently used, behaving pretty well until, quite suddenly, the one made in around 1963 (S/N 019006) had lost its -150 supply, which incapacitated it. Ultimately, it proved to be the 204 volt winding of T600 (120-118) that faltering yet was working again yesterday. Today, out of curiosity, I turned on the other, older 310A and had the same problem, which disappeared when I next turned it on. Also, once both 'scopes were operational, the three supplies were -150, 100.5, and 300.9/-151.6, 100.x, and 300.x - very much within tolerance.

(On the first 310A, I did disconnect the -150 supply from the transformer and found that the voltage on the transformer secondary had dropped from the expected 204 VAC to around 70. Resistance readings between legs were well over a meg Ohm and were over 4 meg Ohm from either leg to chassis. Later, when the transformer produced 204 VAC, I reattached the -150 supply leads and had a functioning scope again.)

Have other 310A owners had similar difficulties? I found no mention of this problem on either of the Tekscope groups. It also, at least initially, made me want to take the bell off the 'top' of the transformer to look for signs of arcing, but it would require a lot of work with the potential of only confirming a dying transformer. Still, if others have encountered this problem and fixed it with something like fish paper stuffed under that transformer bell, or 'top,' I am willing to give it a try.

Both 'scopes have been stored in a climate controlled basement with humidity never reaching more than 40%. Both 'scopes were partly to substantially rebuilt in 2019 and 2020, including the replacement of all electrolytic and film capacitors. Both were working fine just last week, too, although the younger of the two did have a noticeable hum from the transformer, but it had always had that.

Hi:
One of the former members (former member AFAIK) used to rewind some of the 500 series transformers.
He is now? on Tekscopes2.
Don't know if he is doing it anymore.

There is also a litany of discussions, plans, YouTube videos, of failures (and semi-successes) about winding, coil winding machines, and 'potting'
AFAIC there ought to be a reasonable way to deal with replacing these transformers, and generating the high voltage needed.
But 'ought to be' doesn't mean there is

--
Roy Thistle

Hi,
Anyone rewinding these?
My 561 lost its beam...
Thanks

Whether you decide to replace the battery now or not, take a few
minutes to back up your calibration data first. Two easy methods:

1) Use the built-in diagnostic routine EXER 02 and record a video
while scrolling through all 256 calibration values. How to use
EXER 02 is in the service manual.

2) Or, if you have the GPIB option, via the GPIB interface enter
the command "key 0" followed by the command "earom? f" . This will
produce a list of 256 numbers which is the calibration data. Save
this output in a file for future reference.

-mark

On Tue, Apr 8, 2025 at 5:21?PM Sigur?ur ?sgeirsson via groups.io <siggi=
[email protected]> wrote:

My 2467 battery has a '97 date code, still going strong. I have the gear to
calibrate it when it gives up, though.

Sorry, I misremembered. Mine has an '85 date code. Still going strong.

My 2467 battery has a '97 date code, still going strong. I have the gear to
calibrate it when it gives up, though.

On Tue, Apr 8, 2025 at 5:12?PM Jean-Paul via groups.io <jonpaul=
[email protected]> wrote:

We use the date code imprinted on the batteries

Over 5-10 years old, replace regardless of voltage

J

Dale, Mia culpa on the TM faux pas....

As an inventor and having fought many patent infringement cases, I am red,faced...

Thé Staco (tm) are robust and great workbench units.

The GenRad have smaller meters,with glass faces.

We have a Swiss unit that is 240V input, fine German design seems liscencing from GR.

Jon