Somewhat OT but related to over temp…. I remember a 1976 Hughes avionics system we were developing. Very expensive, very complex water cooled metallic backed PCB modules hermetically sealed with sever

@Ken Thanks, that's the name. Looks like they survived to present day better than Tektronix.......

Sparc 10 still in use... What do you use it for? I'd think a discarded i3 laptop would beat it, but I could be mis-informed! On the FG504 issue... Mine has a serial near B0594XX. Had it for 35 years a

Been a long time since I worked on this scope & don’t use it too often. Baseline auto sweep is erratic, choppy, and not full width. All settings of time base and uninfluenced by trigger mode or channe

Most failures on these mainframes are blown pass transistors, rather than lytic caps. I have 4 TM500 frames of various sizes. I can’t remember how many times I’ve replaced those pass transistors I’m s

Surprised no response yet. This is likely one of the common ps faults in the interlock system. Many years since I worked on one, but shorted tantalum caps are often the cause. Search the archives, as

There was a time that many industrial companies has repair and service depts or pools. They would repair anything. I have experience with Hughes and AT&T. These service depts went out of favor with lo

“Get two 155-0076 IC's from Sphere“ Please post your response from Sphere. I have one problematic 485 channel too. Kevin KO3Y

Hi Reed, Great text in ur eBay listing on the 485! I have a theory on the low Vr/Va tantalum failures, but not much data to support it. I suspect that the 485 tantalum “system” follows some form of Ar

The cover for my 485 is 40 years old. Seldom in its proper place, often used as a parts tray, generally crammed into the soft manual & probe bag attached to the top. It is a wonder it is still around.

Hey Peter, Have you really been working on this for 8 years? That’s dedication. I apologize, after looking at your pics I realized you are working on 576, and I have a 577. The 577 is much simpler in

Peter, I had forgot about that looping compensation capacitor Ed mentioned. Do look into it since it sounds like you are digging inside. Let us know what you fine. KJO KO3Y

Is the looping truly visible in every day transistor measurement? Mine is a virgin. It has some looping under some conditions but others the sweep lines are fine. Knobs & switches are somewhat noisy b

Sometimes just a little heat is all that is needed to remove the label. Then it is a matter of finding the minimal solvent for the glue. Kevin Sent from kjo iPhone

@Leo & @Dennis The ethics aside, what is the basis for the claim that 99% of the eBay GPIB-HS are clones? The current eBay price is ~$150USD. These have been around for many, many years. If the “new”

Pretty much everything I have ever seen regarding delta-V bump charging from cell manufacturers or charger makers talk in terms of single cell behavior. It may be easy to design fast delta-V chargers

I’m not to sure how many series cells are in these. But I’ve never seen a balance charger for NiCD or NiMH as is available for Li chemistry. Some form of trickle charging is required to fully charge e

Thanks Chuck Sent from kjo iPhone

So Chuck, regarding #1, I almost never use storage. That being said, I was unaware one could do damage with it off. I’ve had this CT almost 40 years. But I can always learn something new. Don’t keep m

Check out the Fluke-DMM group here.