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The power dissipated by the wet paper is nearly four times as much for 230 V (*) as for 120 V. So you’ll have a runaway much sooner. But the problem does exist at 120 V as well, so don’t get too

Hello, Your movie strongly suggests the deflection is working perfectly and you have a time base issue. I would check and clean the time base switch first. Leo

The following files and folders have been uploaded to the Files area of the [email protected] group. * /IMG_4793.MOV ( /g/TekScopes/files/IMG_4793.MOV ) *By:* clunche

Good morning, Yes, X-Y mode is a bit weirdly done on the 2465. Put the time base knob all CCW to XY; This way the NOT enabled Ch1 will become the horizontal X input, If you select(enable) Ch2, that

Hello gents, I made additional observations this morning. When cold-started, the display shows all the readouts ok but the trace is stuck on the left side doing nothing, except if I turn the

Hello: Seems some confusion of self healing caps vs RIFA failure issues. My understanding: ..... 1/ "self healing" applies to certain metalized film caps: where failed dielectric spot burns away

That hunker.com item is interesting, but not very technical. And to be frank I'm not sure I trust them when they write: "Nearby lightning can induce voltage spikes, as can a car hitting a telephone

ok a 7400 series chip will draw some current when properly biased, that is, the VCC is plus, and the GND is minus.? This current is drawn by the transistors inside, and is voltage dependent.? Once

Harvey Fortunately, they don't remain at zero for long and hold fast once the caps have filled. It is unfortunate that my ESR tester broke just as this story was beginning. Anyway... After

The thing to note is if they *stay* shorted.? Ohms measurements rely on current, and charging a capacitor is dumping as much current as possible into a part (reads zero ohms!) until it charges.?

What wattage is the lamp in your dimbulb setup?

Note in the measurement conditions page it says you need to set B sweep to 100u/s to see the B sweep waveforms. Is it possible that your measurement of pin 16 is without B-sweep? Regarding your other

Hi all. @ Jim Raymond and Renee, Glad to hear that they are pukka caps. I'm heading back to the store in the next few days to buy a small stock, as they had a tray full and they were relatively

Hi, just two questions: If you put it on XY mode (only Ch2 enabled), can you move the dot fully left to right and up to down? What brand is your U800? Leo

Hi Ozan, Thank you for commenting. No, I just checked and I am in normal A sweep. I changed to B-end-A but no change really. I can see the ramp on U800 changing while rotating the hold-off button but

Thanks Roger and Mark, The trace dims or disappears at slow sweep rates and improves as the sweep is switched to faster speeds. I tried it with a faster signal than the internal calibrator and it did

Are you sure the scope is not in B-sweep with "B-ends-A" mode? Fully CW position of Hold-off knob sets B-ends-A, does turning it to CCW direction change anything? Ozan

Morris, You asked about replacement TO-3 transistors in the power supply. I have found BUX48A to work well. The originals I have tested have a too low hfe. The hfe too low made the supplies I worked

The two main switching transistors in the 7934 are labeled Q34 and Q40. They are MJE13007 types. I did a little more research on the ONSEMI website to see if there is a more "beefy" type. I did

Hi James55, This is a transformer based power supply. Take out the dim bulb. Measure for shorts at the out put of every bridge rectifier without powering up. If a short is found, then resolve that.