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Tek 7904 In Pulse Mode Related to C1511 on LV Regulator
The purpose of C1511 is to compensate for the stray capacitance that you have from Q1508B base to ground. This is why a typical value would be for example 10 to 47pF and not 0.1uF. Göran
The purpose of C1511 is to compensate for the stray capacitance that you have from Q1508B base to ground. This is why a typical value would be for example 10 to 47pF and not 0.1uF. Göran
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By
Göran Krusell
· #176027
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Fix or Part Out a Tek 475A
I once went to a course in London, Frequency Synthesis by a Robert Dixon, an American. He said - call me Bob, Mr. Dixon is my father (sorry folks, I could not help it). Göran
I once went to a course in London, Frequency Synthesis by a Robert Dixon, an American. He said - call me Bob, Mr. Dixon is my father (sorry folks, I could not help it). Göran
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Göran Krusell
· #173720
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7A12 attenuator board clone
Mathematically it is not possible to compensate for this problem and the reason is that the dielectric constant is frequency dependent - and this is bad. Göran
Mathematically it is not possible to compensate for this problem and the reason is that the dielectric constant is frequency dependent - and this is bad. Göran
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Göran Krusell
· #173283
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7A12 attenuator board clone
Hi, I recall this topic quite well. Some years ago I uploaded an article from magazine EDN, I believe, which described the difficulties designing high impedance attenuators using an FR4 circuit board.
Hi, I recall this topic quite well. Some years ago I uploaded an article from magazine EDN, I believe, which described the difficulties designing high impedance attenuators using an FR4 circuit board.
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Göran Krusell
· #173256
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Q122/222 Jfet J300 subs for 2215A scope ?
Gentlemen, I have followed this discussion with great interest. However, I have always had difficulty understanding how to design for optimum bias for a FET source follower. In this application, the i
Gentlemen, I have followed this discussion with great interest. However, I have always had difficulty understanding how to design for optimum bias for a FET source follower. In this application, the i
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By
Göran Krusell
· #173137
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Troubleshooting an old Tek 475
Hi, the R1059 and C1059 low pass filter is filtering the +110V voltage, the values are not critical. Göran
Hi, the R1059 and C1059 low pass filter is filtering the +110V voltage, the values are not critical. Göran
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By
Göran Krusell
· #172965
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Tektronix 465 vertical instability problem.
yes, I have. I had a poor connection from vertical board differential output to the pins on the CRT, loose cables. Göran
yes, I have. I had a poor connection from vertical board differential output to the pins on the CRT, loose cables. Göran
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Göran Krusell
· #172245
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TEK 7704A pre-death behaviour a clue to the fault?
Hi, is there a hissing sound? If so you have got arcing. It could be the HV multiplier that is your culprit, this would be bad news. Try to locate my message from several years ago for more details. C
Hi, is there a hissing sound? If so you have got arcing. It could be the HV multiplier that is your culprit, this would be bad news. Try to locate my message from several years ago for more details. C
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By
Göran Krusell
· #172132
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TM500 Plug-in Extention
You need to check every pin if you suspect anything being wrong.
You need to check every pin if you suspect anything being wrong.
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By
Göran Krusell
· #170433
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TM500 Plug-in Extention
Hi, if you have oscillations caused by very long leads to the power transistor, you mentioned 60 cm which would have an inductance of 600nH approximately, then you can most likely solve this by solder
Hi, if you have oscillations caused by very long leads to the power transistor, you mentioned 60 cm which would have an inductance of 600nH approximately, then you can most likely solve this by solder
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By
Göran Krusell
· #170417
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TM 500 Digital Multimeter Recommendations
Hi, do not pick the DM501 or the DM502. If you are measuring voltage and without thinking, like I often do, would turn the switch into the current range your object will be shorted by the multimeter a
Hi, do not pick the DM501 or the DM502. If you are measuring voltage and without thinking, like I often do, would turn the switch into the current range your object will be shorted by the multimeter a
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By
Göran Krusell
· #170192
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Tek 7000 series introduction at WESCON upstaged by HP
Hi, the A sweep runs for a certain amount of time (this is the delay) before the B sweep begins to run (often at a faster rate than the A sweep) Göran
Hi, the A sweep runs for a certain amount of time (this is the delay) before the B sweep begins to run (often at a faster rate than the A sweep) Göran
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By
Göran Krusell
· #168613
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In Defense of the 7A19
I need to comment on this. The lady´s lab bench is way too small. She should have had a bench the same size as her male colleagues. Göran
I need to comment on this. The lady´s lab bench is way too small. She should have had a bench the same size as her male colleagues. Göran
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By
Göran Krusell
· #167954
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Off topic - Electronics Book Club from the 70s and 80s
Also, search for Jim Williams and his design books, this is very good reading! Göran
Also, search for Jim Williams and his design books, this is very good reading! Göran
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By
Göran Krusell
· #165363
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Risetime calculator (in tekwiki)
Hi, what about this approach. To the left you add up 3 admittances and to the right you have one admittance. To the left you adjust for any values you like. To the right you adjust for balance which o
Hi, what about this approach. To the left you add up 3 admittances and to the right you have one admittance. To the left you adjust for any values you like. To the right you adjust for balance which o
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Göran Krusell
· #163477
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Does anyone know Ynvge Von Spalden's current email address?
Perhaps it should be Yngve? That is the way I would spell it. Göran Den lör 4 jan. 2020 23:29Dennis Tillman W7PF <dennis@...> skrev:
Perhaps it should be Yngve? That is the way I would spell it. Göran Den lör 4 jan. 2020 23:29Dennis Tillman W7PF <dennis@...> skrev:
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By
Göran Krusell
· #162715
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7904 with vertical problem
Hi, quite possible that you have an oscillation here. If so something is broken. What you can do is to measure all DC voltages in this amplifier and compare with the schematic. If you find unexpected
Hi, quite possible that you have an oscillation here. If so something is broken. What you can do is to measure all DC voltages in this amplifier and compare with the schematic. If you find unexpected
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By
Göran Krusell
· #160696
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P6249 Oscillation
Hi, there is a peculiar property with emitter followers and FET source followers. Under some circumstances they will provide a negative input impedance. This with a certain source impedance will start
Hi, there is a peculiar property with emitter followers and FET source followers. Under some circumstances they will provide a negative input impedance. This with a certain source impedance will start
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By
Göran Krusell
· #159071
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Again a 7854 power supply beast to be repaired...
More. You can check diodes by making differential measurements across the diode. I found two bad power diodes this way. You can do this measurement while the unit is in tic mode. I found the diodes co
More. You can check diodes by making differential measurements across the diode. I found two bad power diodes this way. You can do this measurement while the unit is in tic mode. I found the diodes co
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By
Göran Krusell
· #156405
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Again a 7854 power supply beast to be repaired...
You need a load of about 50W, possibly equally shared between positive and negative outputs. Either on the raw voltages or after the regulator board. You need to check all caps and diodes on the recti
You need a load of about 50W, possibly equally shared between positive and negative outputs. Either on the raw voltages or after the regulator board. You need to check all caps and diodes on the recti
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By
Göran Krusell
· #156404
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