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Weird (new?) curve tracer on eBay?
Digital scopes are just computers with an analog frontend, they require far fewer if any skilled workers to assemble. You simply couldn't make old analog test equipment even in modern day China. Proba
Digital scopes are just computers with an analog frontend, they require far fewer if any skilled workers to assemble. You simply couldn't make old analog test equipment even in modern day China. Proba
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Marian B
· #168021
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Tektronix 1240 / 1241 innards to give away
Hi All parts went to Raymond. wrote: Maybe a typo in the address? Sorry, but "Not for sale are the front panel boards (incl. IR screen boards)." (I'm using them for a project already) Cheers, Marian
Hi All parts went to Raymond. wrote: Maybe a typo in the address? Sorry, but "Not for sale are the front panel boards (incl. IR screen boards)." (I'm using them for a project already) Cheers, Marian
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Marian B
· #131099
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Tektronix 1240 / 1241 innards to give away
Hi got most innards of said system to give away for someone who needs 'em. Including power supply, CRT drive board (suction cup torn), card cage main board, and cards. Not for sale are the front panel
Hi got most innards of said system to give away for someone who needs 'em. Including power supply, CRT drive board (suction cup torn), card cage main board, and cards. Not for sale are the front panel
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Marian B
· #131057
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Why is Mu Metal used?
(Like many physics explanations, the one below is concise, simple and somewhat wrong) We want to shield an M field. A changing M field *can* be shielded with non-amagnetic conductors (think like the c
(Like many physics explanations, the one below is concise, simple and somewhat wrong) We want to shield an M field. A changing M field *can* be shielded with non-amagnetic conductors (think like the c
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Marian B
· #124566
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CRT article
Indeed a good read! I feel like I should learn more about electron optics, can someone recommend a book about them? Cheers, Marian
Indeed a good read! I feel like I should learn more about electron optics, can someone recommend a book about them? Cheers, Marian
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Marian B
· #124412
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7904 - Very Dim Trace
If you have a few HV caps laying around, built a high-pass with them (a corner frequency of a couple kHz is low enough), then you can measure the AC with basically everything (RMS voltmeter, normal sc
If you have a few HV caps laying around, built a high-pass with them (a corner frequency of a couple kHz is low enough), then you can measure the AC with basically everything (RMS voltmeter, normal sc
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Marian B
· #124360
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7904 - Very Dim Trace
These diodes only rectify a [clipped] sample of the AC-HV: They only need to block about twice the maximum Z axis voltage - approx 80-100 V (depending on grid bias, tube etc), twice that are ~200 V re
These diodes only rectify a [clipped] sample of the AC-HV: They only need to block about twice the maximum Z axis voltage - approx 80-100 V (depending on grid bias, tube etc), twice that are ~200 V re
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By
Marian B
· #124142
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7904 - Very Dim Trace
*If* the X / Y deflection works as before, so calibrated time base steps are still correct and calibrated vert amp steps, too, then you are likely looking at a Z axis issue. I'd recommend to check if
*If* the X / Y deflection works as before, so calibrated time base steps are still correct and calibrated vert amp steps, too, then you are likely looking at a Z axis issue. I'd recommend to check if
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By
Marian B
· #123951
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Happy 70th Birthday
Well, a dark display has zero uncertainty and no calibration required. That's really something! Cheers, Marian
Well, a dark display has zero uncertainty and no calibration required. That's really something! Cheers, Marian
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By
Marian B
· #123741
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Happy 70th Birthday
They actually tried to sell a 120 000 count DMM as "5 1/2 digit"? I'm almost surprised no one in the US sued them for false advertising or something similar. Cheers, Marian
They actually tried to sell a 120 000 count DMM as "5 1/2 digit"? I'm almost surprised no one in the US sued them for false advertising or something similar. Cheers, Marian
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Marian B
· #123732
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Way OT: Undoing ransomware damage
Some older ransomwares could be easily defeated, but most of them are essentially impossible to defeat when they're done encrypting stuff. You have to pay to get the data back. Cheers, Marian
Some older ransomwares could be easily defeated, but most of them are essentially impossible to defeat when they're done encrypting stuff. You have to pay to get the data back. Cheers, Marian
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Marian B
· #123594
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Protected PDF's
Linux, Firefox, Okular works for me just fine, too. Settings -> Configue -> Obay DRM limitations is not checked. Cheers, Marian
Linux, Firefox, Okular works for me just fine, too. Settings -> Configue -> Obay DRM limitations is not checked. Cheers, Marian
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By
Marian B
· #123566
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OT: QService components
Putting the smelly stuff into a bag with some (cheap!) coffee powder (I used cheap coffee ground very finely, like espresso, to great success) for a week or two usually helps. Pro: Doesn't smell like
Putting the smelly stuff into a bag with some (cheap!) coffee powder (I used cheap coffee ground very finely, like espresso, to great success) for a week or two usually helps. Pro: Doesn't smell like
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Marian B
· #123403
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7603 weirdo inverted Z axis
Albert, yes this is what I am thinking. If I remove all inputs to the Z axis amplifier it outputs about 20 V, which should blank the beam - but doesn't. Shorting the input to ground, i.e. full input c
Albert, yes this is what I am thinking. If I remove all inputs to the Z axis amplifier it outputs about 20 V, which should blank the beam - but doesn't. Shorting the input to ground, i.e. full input c
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Marian B
· #123351
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7603 weirdo inverted Z axis
The Z axis amplifier is kinda an op amp in the sense that it is a global feedback amplifier. It does work correctly, both with manually provided inputs and when connected to the Z axis logic. The inte
The Z axis amplifier is kinda an op amp in the sense that it is a global feedback amplifier. It does work correctly, both with manually provided inputs and when connected to the Z axis logic. The inte
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Marian B
· #123319
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7603 weirdo inverted Z axis
Among other issues with this 7603 were the Z axis operation, it seemed like a blanking issue (beam is not blanked correctly), but on closer inspection it is a bit more involved: The intensity control
Among other issues with this 7603 were the Z axis operation, it seemed like a blanking issue (beam is not blanked correctly), but on closer inspection it is a bit more involved: The intensity control
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By
Marian B
· #123314
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7603 Strange HV Need Help
That's a relabeled 7402 ; in later units they are not re-labelled anymore. Generally speaking it seems to me that real Tek ASICs were mostly or exclusively gold plated DIPs (- no problems with the dre
That's a relabeled 7402 ; in later units they are not re-labelled anymore. Generally speaking it seems to me that real Tek ASICs were mostly or exclusively gold plated DIPs (- no problems with the dre
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Marian B
· #123245
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1A4 plug-in on Big Bang
In one of the recent "The Expanse" (Scifi on Syfy) episodes there was a whole bunch of Tek 7000 plugins at the lair of a "data broker". They were, of course, knocked over by the cop. Cheers, Marian
In one of the recent "The Expanse" (Scifi on Syfy) episodes there was a whole bunch of Tek 7000 plugins at the lair of a "data broker". They were, of course, knocked over by the cop. Cheers, Marian
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Marian B
· #123159
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Don't fix if it ain't broke or preventative maintenance
The average HP 3400A has a -3 dB bandwidth of about 5 Hz to 20...25 MHz. I guess that in fact the 3400A set the 20 MHz bandwidth standard for this kind of measurement. Maybe even Tek themselves used 3
The average HP 3400A has a -3 dB bandwidth of about 5 Hz to 20...25 MHz. I guess that in fact the 3400A set the 20 MHz bandwidth standard for this kind of measurement. Maybe even Tek themselves used 3
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By
Marian B
· #123133
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WTB: 7A13 or 7A22 plugin for 7000 series scopes
If he can barter a *really* good discount due to this issue it might still be worth keeping. If only the gears are missing and the divider and pot mechanism are still intact the only thing missing is
If he can barter a *really* good discount due to this issue it might still be worth keeping. If only the gears are missing and the divider and pot mechanism are still intact the only thing missing is
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By
Marian B
· #123026
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