Trying to get Tek 464 scope up and running. What is this part??

[SoulFetish]

I’m stumped I tried searching the manual I tried searching online...
The only thing I can tell you is it’s some sort of add on board (i think), And it was attached to the trigger generator and sweep logic board. Its suffering some serious corrosion



Anyone have any idea?

[olddawg]

Mercury switch? Be careful handling it.

[Enzo]

My first guess is a Hobbs meter. Sorta. A thing to keep track of how many hours are on a system. They use that to see when it needs to go in for regular maintenance. Just my guess. Looks like you are up to close to 2000 hours on yours.

[Tom Phillips]

My first guess is a Hobbs meter. Sorta. A thing to keep track of how many hours are on a system...

If that's the case then maybe you don't need that board in your scope at all. Check and see if it has a voltage feed going into it but no output of any sort. That would indicate the scope doesn't use it to perform any function related to the operation of the scope and you can just leave it out. This means of course that whatever is wrong with the scope is not caused by that module. I have tektronix 465 scopes and have never noticed anything like the part you showed in the photos.

[nevetslab]

I have a part like that in my Tek R5031 Storage Scope. It IS inded an Hours accumulation meter, and as Tom Philips said, it's only an indicator, and not part of a circuit that will shut the scope down if it exceeds so many hours. It was used for doing certain maintenance chores in companies that have a really food meterology deparetment.

[J M Fahey]

Yes, it´s an electro-chemical time indicator.
In the book example form, it´s a solid silver bar inside a glass tube, an electrode at the other end and some electrolytic liquid in the middle.
Silver leaves one end and deposits on the other one, so the center liquid "bubble" appears to move along a scale, until all silver is spent.
Should work with copper too.
Good to check thousands of hours, although it´s not that exact, might have 5 or 10% error, no big deal.

FWIW I am thinking to home make a simple and cheap one, and add it to some "suspect customers" amps, such as those who pay $100 out of a $150 repair bill and *swear* they will bring the rest "in a week".

So I would fit a, say, "30 hour " one, which will mute amp for good after 30 hours effective use have elapsed.
Might be anything between 5 days at a busy rental room or Club and 3 months (calendar time) at somebody´s home who just plays a little on weekends, no big deal, the "non ticking" time bomb will catch him eventually.

Of course, it should look like a heatshrinked 2W resistor or something similar so as not to raise suspicion.
Could be as simple as a piece of plastic tube with a piece of solid copper wire at each end, sealed with an epoxy or Silastic drop and filled with salt water, I´ll have to experiment.
Current will be in the picoamperes or low microamperes region but enough to turn a FET OFF until it opens once it has eaten all copper at one end.

Stay tuned.

[nevetslab]

Ah, ya gotta love the cleverness of smart folk here! Love that proposed shut-down circuit. I can think of a number of folks that deserved one.