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tek 453 external trigger input
Hello, The upper right bnc only affects the delayed signal. Why not try the one for the A time base, at the lower right? A simple 1-volt p-p signal works fine for a trigger level. Also, try using Line
Hello, The upper right bnc only affects the delayed signal. Why not try the one for the A time base, at the lower right? A simple 1-volt p-p signal works fine for a trigger level. Also, try using Line
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Mike Merigliano
· #192460
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Tek 453 resistor specs -- Horiz amp
The diode addition is around Q664, half of the slope comparator pair of transistors. (B-time base) There is also an extra resistor. The soldering looks very neat, as if it was done at the factory, but
The diode addition is around Q664, half of the slope comparator pair of transistors. (B-time base) There is also an extra resistor. The soldering looks very neat, as if it was done at the factory, but
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Mike Merigliano
· #192457
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Tek 453 resistor specs -- Horiz amp
Hello Barry, Metal film could be better, I agree, and I am not committed to carbon film. As I recall, carbon comp had lower inductance than the other two types, but of course they can drift in resista
Hello Barry, Metal film could be better, I agree, and I am not committed to carbon film. As I recall, carbon comp had lower inductance than the other two types, but of course they can drift in resista
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Mike Merigliano
· #192370
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Tek 453 resistor specs -- Horiz amp
Thanks Ozan -- I will look into R1003 and 3F too. The last time I checked (a while ago) all of the power supply voltages were good. But when I open it back up I will double-check. Except for the odd s
Thanks Ozan -- I will look into R1003 and 3F too. The last time I checked (a while ago) all of the power supply voltages were good. But when I open it back up I will double-check. Except for the odd s
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Mike Merigliano
· #192361
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Tek 453 resistor specs -- Horiz amp
Hello Mark, Thanks for the advice -- I will try it soon. I will probably put in 1/4W 1% carbon film to replace the broken ones. That might be over-kill, but the cost difference should be small. I usua
Hello Mark, Thanks for the advice -- I will try it soon. I will probably put in 1/4W 1% carbon film to replace the broken ones. That might be over-kill, but the cost difference should be small. I usua
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Mike Merigliano
· #192360
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Tek 453 resistor specs -- Horiz amp
After checking through most of the circuit involved with the Ext Horiz function, and finding the signal going through all the way to Q824, and still no trace, I figured out what was wrong. After switc
After checking through most of the circuit involved with the Ext Horiz function, and finding the signal going through all the way to Q824, and still no trace, I figured out what was wrong. After switc
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By
Mike Merigliano
· #192344
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Tek 453 resistor specs -- Horiz amp
R646 is okay. It will be awhile before I can dig into it further.
R646 is okay. It will be awhile before I can dig into it further.
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By
Mike Merigliano
· #191810
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Tek 453 resistor specs -- Horiz amp
Thanks to all for the advice, and I am not offended. I measured them in-circuit, and thought they were isolated enough to do that when viewing the schematic. My plan was to find replacements in my sta
Thanks to all for the advice, and I am not offended. I measured them in-circuit, and thought they were isolated enough to do that when viewing the schematic. My plan was to find replacements in my sta
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Mike Merigliano
· #191799
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Tek 453 resistor specs -- Horiz amp
The EXT HORIZ function of my Tektronix 453 does not work, and I found some resistors that were way-out of specification. They are: R634 (reads as 550, should be 11K) R644 (reads as 4k, should be 10K w
The EXT HORIZ function of my Tektronix 453 does not work, and I found some resistors that were way-out of specification. They are: R634 (reads as 550, should be 11K) R644 (reads as 4k, should be 10K w
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Mike Merigliano
· #191794
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453 trigger issues
Hello, The TekScopes articles mentioned earlier are a great place to start. If you lost track of them or cannot find them, contact me at <mmerigATsilverstarDOTcom> and I will send you pdf's. If I reme
Hello, The TekScopes articles mentioned earlier are a great place to start. If you lost track of them or cannot find them, contact me at <mmerigATsilverstarDOTcom> and I will send you pdf's. If I reme
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Mike Merigliano
· #188481
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453 trigger issues
Not sure about mods, but I would really make sure that the problem is with the tunnel diodes in the unit you have. It seems strange that all four of them would have failed. There are other parts of th
Not sure about mods, but I would really make sure that the problem is with the tunnel diodes in the unit you have. It seems strange that all four of them would have failed. There are other parts of th
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Mike Merigliano
· #188409
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453 trigger issues
Hello, The first one in Charles Phillips' series was in February 1969. This is the volume when Service Scope was renamed "TEKscope", which in turn includes Service Scope. The look changed somewhat as
Hello, The first one in Charles Phillips' series was in February 1969. This is the volume when Service Scope was renamed "TEKscope", which in turn includes Service Scope. The look changed somewhat as
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By
Mike Merigliano
· #188090
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453 trigger issues
The Tektronix "Service Scope" publication had a series of articles by Charles Phillips. At least two of them maybe helpful: Troubleshooting the 453 Troubleshooting Trigger Circuits I think the Tekscop
The Tektronix "Service Scope" publication had a series of articles by Charles Phillips. At least two of them maybe helpful: Troubleshooting the 453 Troubleshooting Trigger Circuits I think the Tekscop
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By
Mike Merigliano
· #188084
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How to explain how negative feedback lowers noise?
What's wrong with mentioning the IEEE? I know a little bit about it (a good friend of mine is a past president, and we talk about it sometimes). Just curious, as a non-EE person. This is already off-t
What's wrong with mentioning the IEEE? I know a little bit about it (a good friend of mine is a past president, and we talk about it sometimes). Just curious, as a non-EE person. This is already off-t
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Mike Merigliano
· #181060
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How to explain how negative feedback lowers noise?
As a non-EE, maybe my take on this could be useful, because the OP was looking for a non-technical analogy or explanation. But it should still be accurate. The kids going into the house example does n
As a non-EE, maybe my take on this could be useful, because the OP was looking for a non-technical analogy or explanation. But it should still be accurate. The kids going into the house example does n
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Mike Merigliano
· #180813
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Message from your fearless (foolish?) leader
Hello Dennis, Good luck to your wife, and I hope your cooking skills improve fast enough to avoid disaster. Once in a while I get email bounce messages from tekscopes.io, that sound like what you are
Hello Dennis, Good luck to your wife, and I hope your cooking skills improve fast enough to avoid disaster. Once in a while I get email bounce messages from tekscopes.io, that sound like what you are
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By
Mike Merigliano
· #180447
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465B strange ripple
Hello, Earlier today, you said: "ALL the low voltage supplies test ok and have no ripple whatsoever. That, of course, applies to the 55V as well." Then why would you replace the cap(s) on the 55 v sup
Hello, Earlier today, you said: "ALL the low voltage supplies test ok and have no ripple whatsoever. That, of course, applies to the 55V as well." Then why would you replace the cap(s) on the 55 v sup
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By
Mike Merigliano
· #179408
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465B strange ripple
Okay, you did all of the tests, but it was hard to tell given the reporting. For example, is the 55 VDC supply okay as far as ripple goes? I am not the only one to ask about this. Also, using "ripple"
Okay, you did all of the tests, but it was hard to tell given the reporting. For example, is the 55 VDC supply okay as far as ripple goes? I am not the only one to ask about this. Also, using "ripple"
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Mike Merigliano
· #179303
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465B strange ripple
Hello Stephen, Although I don't have a 465B, I have been following this thread because line-frequency noise can be so hard to track down, in many types of things, and was curious about how this all wo
Hello Stephen, Although I don't have a 465B, I have been following this thread because line-frequency noise can be so hard to track down, in many types of things, and was curious about how this all wo
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Mike Merigliano
· #179280
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465B strange ripple
There may be a loose grounding screw. There is a document on cleaning the switches in 4xx scopes, and within it is this: "One OTHER thing to check: (I'm not sure, at the moment, if this is only for th
There may be a loose grounding screw. There is a document on cleaning the switches in 4xx scopes, and within it is this: "One OTHER thing to check: (I'm not sure, at the moment, if this is only for th
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Mike Merigliano
· #178347
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