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Tek 455 Vertical deflection question
+95V is generated from HV transformer. If you observe TP+95V in sheet <2> (CRT & Z Axis sheet), does it stay regulated or does it change with intensity? Ozan
+95V is generated from HV transformer. If you observe TP+95V in sheet <2> (CRT & Z Axis sheet), does it stay regulated or does it change with intensity? Ozan
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Ozan
· #193605
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Tek 455 Vertical deflection question
Schematic says nominal is 52.2V, measured voltage looks reasonable. Ozan
Schematic says nominal is 52.2V, measured voltage looks reasonable. Ozan
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Ozan
· #193604
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OT: Housing Voltage in an Autotransformer
In most analog meters input impedance changes with the range. Picture of 269 says 5k-ohm/V in AC, you are changing the shunting impedance as well when you are changing the range. Ozan
In most analog meters input impedance changes with the range. Picture of 269 says 5k-ohm/V in AC, you are changing the shunting impedance as well when you are changing the range. Ozan
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Ozan
· #193468
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7A16A high frequency compensation.
This is a real puzzle. In the pictures there is a metal connection between attenuator and the amplifier, roughly between CR130 and CR507 (CR507 shows up in board layout but not in schematic). Probably
This is a real puzzle. In the pictures there is a metal connection between attenuator and the amplifier, roughly between CR130 and CR507 (CR507 shows up in board layout but not in schematic). Probably
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Ozan
· #193466
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2465A battery backup
In this context it is one of the ESD discharge models: Charged-Device Model. Board may have charge on it because it is not grounded, when a ground potential connector (e.g. soldering iron) touches the
In this context it is one of the ESD discharge models: Charged-Device Model. Board may have charge on it because it is not grounded, when a ground potential connector (e.g. soldering iron) touches the
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Ozan
· #193427
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2465A battery backup
With the board floating only concern is CDM as Ross mentioned. Touch the ground of the board with tip of the soldering iron (i.e. ground it) before touching any internal traces. Ozan
With the board floating only concern is CDM as Ross mentioned. Touch the ground of the board with tip of the soldering iron (i.e. ground it) before touching any internal traces. Ozan
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Ozan
· #193414
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7A16A high frequency compensation.
5mV and 10mV are the only settings in which there is a direct path from gate of the source follower to BNC. Probably this says something is happening at or to the left side of switch 5. Did AC/GND/DC
5mV and 10mV are the only settings in which there is a direct path from gate of the source follower to BNC. Probably this says something is happening at or to the left side of switch 5. Did AC/GND/DC
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Ozan
· #193402
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Help with diagnosis of Tek 2465 Power Supply Problem
Congratulations for the fix. Ozan
Congratulations for the fix. Ozan
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Ozan
· #193370
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7A16A high frequency compensation.
Very impressive setup. On similar cam based switches sliding a thick paper soaked in IPA between the contacts worked well. I believe this is also what Tek recommends. Ozan
Very impressive setup. On similar cam based switches sliding a thick paper soaked in IPA between the contacts worked well. I believe this is also what Tek recommends. Ozan
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Ozan
· #193365
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Tek 2465A Frequency readout
In the first picture you are in 50-ohm mode but in later pictures you are in 1M-ohm DC mode. In 50-ohm mode I tested frequency measurement function up to 650MHz on a 2467B, which is very similar to 24
In the first picture you are in 50-ohm mode but in later pictures you are in 1M-ohm DC mode. In 50-ohm mode I tested frequency measurement function up to 650MHz on a 2467B, which is very similar to 24
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Ozan
· #193364
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7A16A high frequency compensation.
Because of C132 high frequencies (or faster edges) will see a lower impedance. However, it should still be relatively higher impedance than the 50-ohm source. Do you put the attenuator at source side
Because of C132 high frequencies (or faster edges) will see a lower impedance. However, it should still be relatively higher impedance than the 50-ohm source. Do you put the attenuator at source side
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Ozan
· #193330
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Help with diagnosis of Tek 2465 Power Supply Problem
In the error light pattern are Ch1-4 lights off? If you push delta-V/delta-T/slope buttons all at once you will enter the test menu. Then if you push "Trigger coupling" up button scope should run a sm
In the error light pattern are Ch1-4 lights off? If you push delta-V/delta-T/slope buttons all at once you will enter the test menu. Then if you push "Trigger coupling" up button scope should run a sm
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Ozan
· #193325
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7A16A high frequency compensation.
Waveforms look like reflections coming from the cable between signal source and the plugin. If you double the length of the coax you use, does the place where first step happens in the middle picture
Waveforms look like reflections coming from the cable between signal source and the plugin. If you double the length of the coax you use, does the place where first step happens in the middle picture
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Ozan
· #193318
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7A16A high frequency compensation.
All the DC voltages look fine. Unless there is a subtle failure mechanism that doesn't show up in DC operating point JFET looks good. If you probe left side of R132, is rising edge clean? If left side
All the DC voltages look fine. Unless there is a subtle failure mechanism that doesn't show up in DC operating point JFET looks good. If you probe left side of R132, is rising edge clean? If left side
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Ozan
· #193313
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TDS540 repair; drifting vertical position at start-up
There is some chemistry reasons (I don't remember the details) for some deposits not dissolving in alcohol. I also found these boards to have so much electrolyte residue it was difficult to completely
There is some chemistry reasons (I don't remember the details) for some deposits not dissolving in alcohol. I also found these boards to have so much electrolyte residue it was difficult to completely
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Ozan
· #193312
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Help with diagnosis of Tek 2465 Power Supply Problem
C000 EPROM looks correct with code 1626-04 and start address of C000. All the data bits are exercised too (bitwise or gives 0xff), only remaining unexercised connection is the address bus. Perhaps one
C000 EPROM looks correct with code 1626-04 and start address of C000. All the data bits are exercised too (bitwise or gives 0xff), only remaining unexercised connection is the address bus. Perhaps one
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Ozan
· #193302
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Help with diagnosis of Tek 2465 Power Supply Problem
Hi Luca, I saw the other post, it looks like you are indeed getting a EPROM checksum error. I was thinking it is a parity error, which happens for calibration memory. Since you are seeing correct cont
Hi Luca, I saw the other post, it looks like you are indeed getting a EPROM checksum error. I was thinking it is a parity error, which happens for calibration memory. Since you are seeing correct cont
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Ozan
· #193300
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Help with diagnosis of Tek 2465 Power Supply Problem
Congratulations for the PSU fix. Service manual Exercise 02 can give more clues about the parity error. Ozan
Congratulations for the PSU fix. Service manual Exercise 02 can give more clues about the parity error. Ozan
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Ozan
· #193297
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TDS540 repair; drifting vertical position at start-up
Hi Ralph, This is most likely because of a leakage path from U1101 input to negative supply. Did you wash the board after unsoldering bad caps? Everyone has their own recipe but 50% vinegar-water solu
Hi Ralph, This is most likely because of a leakage path from U1101 input to negative supply. Did you wash the board after unsoldering bad caps? Everyone has their own recipe but 50% vinegar-water solu
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Ozan
· #193275
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TDS540 repair; drifting vertical position at start-up
Hi Ralph, My comments are below. This may be another open trace or control voltage issue. Interpolator makes heavy use of calibration voltages. I had similar errors on TDS520’s that cleared up once re
Hi Ralph, My comments are below. This may be another open trace or control voltage issue. Interpolator makes heavy use of calibration voltages. I had similar errors on TDS520’s that cleared up once re
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Ozan
· #193223
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