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Tek. 454 no triggering on A or B
I have a 454 that will not trigger on A or B timebase. I bought knowing of the triggering problem. I have scoped the signal and it will not go through T670. Overhauling the unit did not help. The powe
I have a 454 that will not trigger on A or B timebase. I bought knowing of the triggering problem. I have scoped the signal and it will not go through T670. Overhauling the unit did not help. The powe
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Mark Vincent
· #179621
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7104 out of focus/astigmatism
Francesco and Michael, Measure the heater voltage first. If low, go to the second paragraph. If you know it sat a long time before you started using it, read below. You scopes might have been sitting
Francesco and Michael, Measure the heater voltage first. If low, go to the second paragraph. If you know it sat a long time before you started using it, read below. You scopes might have been sitting
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Mark Vincent
· #179392
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1L10 crystal needed (Newbie)
Joel, This place says it has the 900kc crystal you want. I do not know if it the physical style you need. The site is: https://lokoselectronics.com/products/khz-crystals/ . I do not know if you looked
Joel, This place says it has the 900kc crystal you want. I do not know if it the physical style you need. The site is: https://lokoselectronics.com/products/khz-crystals/ . I do not know if you looked
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By
Mark Vincent
· #179030
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7104 out of focus/astigmatism
Francesco, Spray the cooler on C1736, C1770 and C1771 when the scope is warmed up. If the trace becomes like it is when the unit is cold, that means that these should be replaced. The first one I repl
Francesco, Spray the cooler on C1736, C1770 and C1771 when the scope is warmed up. If the trace becomes like it is when the unit is cold, that means that these should be replaced. The first one I repl
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By
Mark Vincent
· #178801
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549 transformer question
Chuck or anyone else with knowledge, I was wondering if any/some/none of the following could be used in the rewinding of the transformers that might make operation like it should be for a long life. K
Chuck or anyone else with knowledge, I was wondering if any/some/none of the following could be used in the rewinding of the transformers that might make operation like it should be for a long life. K
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By
Mark Vincent
· #178225
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[dead tek 485] Can i fix it ? (newbie here)
Raymond and Tom, I stated what I have experienced. In no way was I attempting to imply what I have seen is the only solution. I hope I did not offend anyone by posting what I experienced or suggested.
Raymond and Tom, I stated what I have experienced. In no way was I attempting to imply what I have seen is the only solution. I hope I did not offend anyone by posting what I experienced or suggested.
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By
Mark Vincent
· #177308
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[dead tek 485] Can i fix it ? (newbie here)
Jose, Check the 9V zener, VR2042. It is open. ALL 9V zeners I find in Teks are open. I replace them with the BZX85B9V1. I know this zener is in the 50V supply. The condensers, C2086 and C2087, could b
Jose, Check the 9V zener, VR2042. It is open. ALL 9V zeners I find in Teks are open. I replace them with the BZX85B9V1. I know this zener is in the 50V supply. The condensers, C2086 and C2087, could b
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By
Mark Vincent
· #177295
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7904A restoration questions
Dave, I restored one of these earlier this year. I upped the capacitance of the condensers and used high temp. low ESR and long life ones. I restuffed the two main screw cans with 1200mfd 250V LGR typ
Dave, I restored one of these earlier this year. I upped the capacitance of the condensers and used high temp. low ESR and long life ones. I restuffed the two main screw cans with 1200mfd 250V LGR typ
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By
Mark Vincent
· #175555
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7904A restoration questions
Dave,
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Mark Vincent
· #175554
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Finding good homes for older Tektronix equipment (547, plugins, 454A)
Jeff, I am interested in getting items from you. I would like to know what you have, working condition, willingness to ship and prices. Thanks. Mark
Jeff, I am interested in getting items from you. I would like to know what you have, working condition, willingness to ship and prices. Thanks. Mark
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By
Mark Vincent
· #175002
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151-0367-00 and 151-0402-00 transistors
These are likely to be leaky from C to E as a diode while checking normal as an NPN. An hfe meter will show way off hfe on the leaky ones. If they have round leads (tarnished above the socket), they a
These are likely to be leaky from C to E as a diode while checking normal as an NPN. An hfe meter will show way off hfe on the leaky ones. If they have round leads (tarnished above the socket), they a
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By
Mark Vincent
· #174012
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Anyone willing to make 3D printing of multiplier boxes
Mr. Lynch, The photos of your enclosures are nice. I am glad to see a supplier that has these cases for those that have bad multipliers. I brought it up since some have said their multiplier is bad an
Mr. Lynch, The photos of your enclosures are nice. I am glad to see a supplier that has these cases for those that have bad multipliers. I brought it up since some have said their multiplier is bad an
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By
Mark Vincent
· #173818
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Anyone willing to make 3D printing of multiplier boxes
I was wondering if anyone was willing to make the boxes for the multipliers so ones that go bad can be made. The box would need the holes for the wires and mounting threads as original. The old epoxy
I was wondering if anyone was willing to make the boxes for the multipliers so ones that go bad can be made. The box would need the holes for the wires and mounting threads as original. The old epoxy
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By
Mark Vincent
· #173792
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OS-34/URM-32 and OS-4B/AP schematics wanted
I am looking for the schematics of the two military scopes. I prefer paper or print-out. Thanks. Mark
I am looking for the schematics of the two military scopes. I prefer paper or print-out. Thanks. Mark
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Mark Vincent
· #173791
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Choosing the right replacement cap
Dave, C1419 is a sealed tantalum that usually does not go bad. If it goes bad, a 47 or 56mfd 25 or 35V Nichicon ULD is what I would recommend. That series is low ESR, high temperature and long life. T
Dave, C1419 is a sealed tantalum that usually does not go bad. If it goes bad, a 47 or 56mfd 25 or 35V Nichicon ULD is what I would recommend. That series is low ESR, high temperature and long life. T
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By
Mark Vincent
· #173698
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Caps for a TM5006
Eric, The caps you should use on the mains would be Nichicon LGR 1200mfd 250V (C1210 and C1510). This LGR is what I use to restuff the 950mfd in the 7000 series. The 3mfd, C1240, can be a film type at
Eric, The caps you should use on the mains would be Nichicon LGR 1200mfd 250V (C1210 and C1510). This LGR is what I use to restuff the 950mfd in the 7000 series. The 3mfd, C1240, can be a film type at
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By
Mark Vincent
· #172814
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Tektronix 2465A noise on readout
Gregor, I read somewhere online about R1853, R1854, R1871, R1872 and R1880 are prone to opening or going high causing focus problems. The originals are 1/4W. The suggested replacements should be 1W 1%
Gregor, I read somewhere online about R1853, R1854, R1871, R1872 and R1880 are prone to opening or going high causing focus problems. The originals are 1/4W. The suggested replacements should be 1W 1%
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By
Mark Vincent
· #172338
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516 Triggering not working
John, Looking at page 5-8 indicates mine is with the high voltage at the plate of the Miller tube V161A. Grounding the grid did make the difference in the paragraph; stuck in run up position. Zero swe
John, Looking at page 5-8 indicates mine is with the high voltage at the plate of the Miller tube V161A. Grounding the grid did make the difference in the paragraph; stuck in run up position. Zero swe
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By
Mark Vincent
· #172337
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516 Triggering not working
I have been working on the circuit for a week after the 27mmfd to the Sweep Gating Multivibrator and Hold-Off Circuit with no success. All I get now is a spot, no horiz. line. The part before the 27mm
I have been working on the circuit for a week after the 27mmfd to the Sweep Gating Multivibrator and Hold-Off Circuit with no success. All I get now is a spot, no horiz. line. The part before the 27mm
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By
Mark Vincent
· #172334
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TEK 7704A pre-death behaviour a clue to the fault?
I would like to make an amend on the the use of GD900-1. It can be used with higher voltages if used VERY carefully. A bottle of this will go a long way. Make sure to use a small(!) amount, press the
I would like to make an amend on the the use of GD900-1. It can be used with higher voltages if used VERY carefully. A bottle of this will go a long way. Make sure to use a small(!) amount, press the
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By
Mark Vincent
· #172149
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