Re: 5440 PS transistor selection
Thanks Harvey,toggle quoted messageShow quoted text
I did discover the plug-in incompatibility when I tried installing the 5440 plug-ins in the 5111A. Jeff Dutky pointed me to the pertinent section of the Tek Wiki that describes this.
In that I also found that the 5111A plug-ins are "forward compatible" and work in the 5440. I was a tad surprised to see the 5A26 from the 5111A gave readouts on the 5440. While tuning up the 5440, on a lark, I used the 5A26 from the 5111A and the 5A48 from the 5440 to prove I could get four channels showing at once with 5 readouts. The time base is a delayed 5B42, but can't do "dual" A/B sweeps. (That'd be 8 sweeps! :P) But it did prove the scope could do the 4 channels. FWIW. I don't have much experience with these scopes, so I don't even know if a dual delayed sweep time base is available or possible. I rather doubt it. So I don't think there's a lower-right quadrant readout to be had. I digress. Readouts are a whole other thread!
The calibration procedure in the 5440 manual is rather brief, but it does include a HV voltage check, which was within spec. The 5A48 need some very slight tweaking to bring CH1 & CH2 into agreement and get the step attenuator adjustments spot on. Once it was tuned it did very well with edge compensation and provides very nice sharp traces across the volts/div range. Noise, of course, shows up below 5mV/div. But that's to be expected (see my other posts about my large FM interference from local broadcast tower).
The horizontal cal seems a bit deficient, and the time base should be calibrated too. It also has some knob damage to the delayed time/div portion that I'll need to fix. And some switch maintenance. It'll need to be partially disassembled to get at them. These issues are minor and don't appear to affect the horizontal performance. The timing accuracy and stability are good.
Perhaps I need to check the 5CT1N supplies in the center slot of the 5440? Could it be a supply issue in the curve tracer? The cal does have one swapping the vertical plug-in back and forth between the left and right slots to verify vertical position and gain. And I ran through the volts/div ranges with a PG506 in both slots. Both producing accurate and sharp traces. But that doesn't guarantee the 5CT1N is happy, does it. The shorted tantalum decoupling cap was right next to the center slot, for what that's worth. I replaced it with a 50v tantalum with the same 1uF value.
I'll have to run through a 5CT1N check-out in the 5440, now that you've brought that up Harvey. Thanks for the suggestion.
On Tuesday, June 15, 2021, 07:22:50 AM PDT, Harvey White <firstname.lastname@example.org> wrote:
You might want to check on this, but the 5000 series plugins and the
5400 series plugins were not supposed to be interchangeable. I think you
certainly couldn't use a 5400 series in a 5000, and I *think* that the
reverse is true.
They are not the same scope series, from what I know.
Fat blurry traces indicates that the supply voltages are off, the HV is
likely strange, etc. Not sure, but I'd do a very close read on the manual.
On 6/15/2021 1:25 AM, Dave Peterson via groups.io wrote:
To wrap this case: