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#1
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Okay, so how do I go about checking my scope for proper AC voltage calibration? I just tested another point that is supposed to be 170VPP. With the scope on 50V/Div I get almost 4.5 divisions. That's almost 225VPP. I checked with my DMM and it reads as 130VAC. I check the one next to it that was supposed to be 20VPP and it showed as 25VPP. The DMM had it as 16.9VAC. I'm pretty sure my DMM isn't showing the exact voltage (everyone keeps writing about RMS and such).
I need to know if there's something wrong with my scope. If so I need to return it to be fixed. Thanks!
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Pioneer SX-1080, Pioneer PL-115D, Pioneer CT-F9191, Pioneer RG-1, Wollensak 8050A, Akai 4000DS MkII, Pioneer CS-05 & Polk 1.2TL Denon 5803A, Pioneer DVL-700, Pioneer CT-W603RS, Toshiba HD-A3, D-Link DSM-520, Dish VIP-722, Polk 1.2TL, CSi5, LS/fx, RT-800 and PSW-650 |
#2
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...
Last edited by andy; 12-05-2021 at 07:51 PM. |
#3
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Quote:
See my other post where the 125VAC shows up as 325V on the scope.
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Pioneer SX-1080, Pioneer PL-115D, Pioneer CT-F9191, Pioneer RG-1, Wollensak 8050A, Akai 4000DS MkII, Pioneer CS-05 & Polk 1.2TL Denon 5803A, Pioneer DVL-700, Pioneer CT-W603RS, Toshiba HD-A3, D-Link DSM-520, Dish VIP-722, Polk 1.2TL, CSi5, LS/fx, RT-800 and PSW-650 |
#4
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Who makes your dmm, where did you get it, and how much$.
The pins at the horiz board, tp5 is 123, next one down is 124, and bottom is 6. The schematic you posted is not that clear, and gets worse when I blow it up, so If you check the voltages at each one of these points, are they correct, higher, lower? You need to post "posted" value as in (sams) and actual, (what you read), How DMM Scope. How about the wave form at the base of the HOT? is it good? The diode, and cap in the collector circuit closest to the HOT on the schematic? they good? Does the schematic detail the meter used ? for sams voltage readings?
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Yes you can call me "Squirrel boy" Last edited by Username1; 10-02-2013 at 04:29 PM. |
#5
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Quote:
I will check those other points and post their voltage and the Sams voltages. I was told that the diode on the HOT had to be good since the HOT would be dead if it wasn't. As for the capacitor, I didn't test. Can I use an ESR meter to test it? I believe if I pull the hot, I should be able to test that capacitor without disconnected a leg an it should be pretty much isolated at that point. I will put the set on her side and remove the bottom to get the waveform of the base of the HOT.
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Pioneer SX-1080, Pioneer PL-115D, Pioneer CT-F9191, Pioneer RG-1, Wollensak 8050A, Akai 4000DS MkII, Pioneer CS-05 & Polk 1.2TL Denon 5803A, Pioneer DVL-700, Pioneer CT-W603RS, Toshiba HD-A3, D-Link DSM-520, Dish VIP-722, Polk 1.2TL, CSi5, LS/fx, RT-800 and PSW-650 |
Audiokarma |
#6
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Hopefully, this step is completed already..... Remember the scope videos we talked about looking at earlier.
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Yes you can call me "Squirrel boy" |
#7
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Quote:
How about I do the horizontal sweep again and when the 170VPP waveform comes up I take a picture of the entire front of the scope so all the settings can be seen?
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Pioneer SX-1080, Pioneer PL-115D, Pioneer CT-F9191, Pioneer RG-1, Wollensak 8050A, Akai 4000DS MkII, Pioneer CS-05 & Polk 1.2TL Denon 5803A, Pioneer DVL-700, Pioneer CT-W603RS, Toshiba HD-A3, D-Link DSM-520, Dish VIP-722, Polk 1.2TL, CSi5, LS/fx, RT-800 and PSW-650 |
#8
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Your camera will adjust to the brightest items, so set the trace very dim, and the graticule very dim as well. You can set the sweep to display one or two cycles of the pulse, just turn the knob to what you want. Set the vert volts/div. so you get close to a full screen, it will be easier to read that way..... you know 3 to 4 divisions is more accurate than say 3/4's of a cm..... or 3/4's division...
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Yes you can call me "Squirrel boy" |
#9
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Quote:
EDIT: Added a third pic as you can't read the face without the flash lighting it up.
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Pioneer SX-1080, Pioneer PL-115D, Pioneer CT-F9191, Pioneer RG-1, Wollensak 8050A, Akai 4000DS MkII, Pioneer CS-05 & Polk 1.2TL Denon 5803A, Pioneer DVL-700, Pioneer CT-W603RS, Toshiba HD-A3, D-Link DSM-520, Dish VIP-722, Polk 1.2TL, CSi5, LS/fx, RT-800 and PSW-650 Last edited by TinCanAlley; 10-02-2013 at 05:19 PM. |
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ok, so its about 3.5 divisions, which v/div are you using? what does it work out to be...?
just under 175v if you are using 10x probe?
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Yes you can call me "Squirrel boy" |
Audiokarma |
#11
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That is correct.
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Pioneer SX-1080, Pioneer PL-115D, Pioneer CT-F9191, Pioneer RG-1, Wollensak 8050A, Akai 4000DS MkII, Pioneer CS-05 & Polk 1.2TL Denon 5803A, Pioneer DVL-700, Pioneer CT-W603RS, Toshiba HD-A3, D-Link DSM-520, Dish VIP-722, Polk 1.2TL, CSi5, LS/fx, RT-800 and PSW-650 |
#12
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Lets try something a little different....
Measure that same spot using d.c. 1. put the scope on gnd. using that 3 position switch input for channel 2 2. move the display trace to a lower line on the grid, using the position knob. 3. turn the 3 position knob to dc, then measure the 125v source, see that it reads 125. 4. check tp5 again, see if it saturates at what the 125v source is...
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Yes you can call me "Squirrel boy" |
#13
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Quote:
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Pioneer SX-1080, Pioneer PL-115D, Pioneer CT-F9191, Pioneer RG-1, Wollensak 8050A, Akai 4000DS MkII, Pioneer CS-05 & Polk 1.2TL Denon 5803A, Pioneer DVL-700, Pioneer CT-W603RS, Toshiba HD-A3, D-Link DSM-520, Dish VIP-722, Polk 1.2TL, CSi5, LS/fx, RT-800 and PSW-650 Last edited by TinCanAlley; 10-02-2013 at 05:55 PM. |
#14
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At this point, I am going to assume your 125v source may be 140V.
You are also seem to be having different readings on your two pieces of test equipment. You will have to figure out how you want to deal with that. I would check through the low voltage power supply where the 125v comes from, and check through the voltages listed there, there should be 4 or 5 low supply spots you can test, Use both your dmm, and the scope on DC, see which one you are more willing to trust. If that 125v is way off, then your HV may be using too much power and creating that ring just because the voltage is too high.... If you can, please post the power supply circuit, lets see if its a doubler with a possible bad part making too much voltage..... I'm sorry to be casting doubt on your test equipment, but I have been there before, it may seem to be a stupid step, but we have to follow the evidence we have to find the real problem.
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Yes you can call me "Squirrel boy" |
#15
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Here's my results with the base of the HOT. I'm attaching the Sams waveform (not very clear) and mine. I had my scope set on 2V/div and as you can see it filled the display. It's about 16V. The Sams has it as 7V.
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Pioneer SX-1080, Pioneer PL-115D, Pioneer CT-F9191, Pioneer RG-1, Wollensak 8050A, Akai 4000DS MkII, Pioneer CS-05 & Polk 1.2TL Denon 5803A, Pioneer DVL-700, Pioneer CT-W603RS, Toshiba HD-A3, D-Link DSM-520, Dish VIP-722, Polk 1.2TL, CSi5, LS/fx, RT-800 and PSW-650 |
Audiokarma |
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