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“Drops exponentially”, of course. Fat-fingered the autocomplete choice Sent from my iThing; please forgive the typos and brevity

Although the TI socket’s problems are well known, all sockets can have flaky contacts. True netal-to-metal contacts probably don’t really exist when you abut them. There’s always a thin layer

Readout function has been intermittent in my 7704A since I bought it last year. It will work fine for weeks and then suddenly stop. It may resume on its own after a few days but most of the time

There are really only two possibilities: The diode is bad (did it check 0.7V forward bias and open circuit reverse direction?) or it is inserted backwards (does the cathode really go to base of

Jeff, the guy I bought it from said that mostly he replaced electrolytic capacitors.? I haven't done anything to it.? The reason I decided not to sell it is that I was mistaken about the bad

Stephen, It's still an open question what's going on here. Later on you checked S242B, but did you also check that the wiper of R246 is not open circuit? Albert

There still are issues with the +15v at least. Last night the readings were taken with the CR1751 and CR1732 disconnected. This morning, I tested the +65v adj screw and it was working. Once

Hello Jon, AFAIK, the EPROMs are soldered in, at least they were in one other instrument that was mentioned at the time in this group. It would be wonderful if you could/would desolder them if

--- There were two issues. Even with opamp supply totally dead due to "B" side, VR1724 should have kept base of Q1732 above ~56V if opamp were the only issue. However, Q1732 base was at 26V. No

I see…. But what harm could it do to change them? I haven’t yet. That makes sense, indeed. I will check what mine does, and report the values. Thanks Albert

Stephen, I would say don't! Even if 3 resistors are open and one is 10 k you would have higher output amplitude than what you found. All 4 resistors open might occur I think when R99 is open and no

Hi Raymond, I'm away at the moment but I'll take the lid off over the weekend and have a look inside, see what's what and report back. Hopefully the EPROMs and PALs are socketed and the PALs don't

Bob, just wondering what has been done to that scope? Is it still giving problem in one channel? Asking because I have 3 2440's, 2 2432's, 1 2432A and a few 2430A,s all waiting on parts to repair

Mark, Dave, Albert, I’ve taken a closer look at the 2.2K resistors at pin 9. 3 of them show quite a bit of discoloration due to extensive heat…. I shall change them and see…. They may have

On Tue, Mar 22, 2022 at 07:48 PM, Albert Otten wrote: > > Hi Stephen, > > So you have -161 V at pins 3 of the output tubes, but hardly an output signal. > When there is no nearly short circuit

With 8 or 9 hours of time difference a lot has happened since I went to sleep! Last night I had got as far as realising that U1724A was sinking current at its output so was not going to be

Ozen, I just tried that as well, for Ch 1 and Ch 2, in both 1 MΩ and 50 Ω modes, all scales read as 1 MΩ (998 kΩ - 1.002 MΩ) in the 1 MΩ mode, and as 50 Ω (50.3 Ω - 50.6 Ω) in the 50 Ω

I noticed a typo below, diode checker should show ~ +0.7V in forward direction, not -0.7:

Hi Jeff, Multimeter should be fine. I just did the test on my 2467B showing 1M at all ranges. Ozan

Ozan, Sorry, I’m running on a bit of a sleep deficit, and I got the sender names confused in the thread. Can I just use a multimeter to check then impedance of the scope input? — Jeff Dutky