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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

We use the date code imprinted on the batteries

Over 5-10 years old, replace regardless of voltage

J

On 8 Apr 2025 4:36 pm, Jean-Paul wrote:

As we were power elecronics designers since 70s' we have a collection of Variacs, the best are indeed the old Staco and GenRad with ACV RMS and AC .

Jean-Paul -

A Staco is not a "Variac," which is a registered trademark. The original Variacs were the variable autotransformers made by General Radio Company. The current holder of the trademark is ISE, Inc.

The variable autotransformers made by Staco Energy Products have the registered trademark StacoVT. Those made by Superior Electric have the registered trademark POWERSTAT.
--
Dale H. Cook, GR/HP/Tek Collector, Roanoke/Lynchburg, VA

David and Dale: YES on all:

As we were power elecronics designers since 70s' we have a collection of Variacs, the best are indeed the old Staco and GenRad with ACV RMS and AC .

Mains in UK EU = power line in USA

The voltage mentioend ar efine.

Alternate is an un metered variac and use the knob calibration for V .

Add aseries AC ammeter (or clamp on whith splitter) but the clamp on are no accurate.

Today we are working on a trusty 7603 mainframme TEK with blown linear PSU, that draws normal till a few sec at 30-60V

Then lets losse with 2-4 A curretn , smoke and smells...

Its a dyiung lytic on the rectifier board, an on FP can


Enjoy,


Jon

On 8 Apr 2025 9:47 am, David Berlind wrote:

Thanks @Jean-Paul. What do you mean by "metered" variac.

I suspect that he means one of the portable Variacs supplied cased with an output voltmeter, such as the Type W8MT3VM.

For field use I built my own portable cased Variac with an output voltmeter and ammeter, and fuse-protected input and output:


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