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Quote from: 0culus on September 27, 2019, 11:39:32 pmQuote from: Cubdriver on September 27, 2019, 11:32:50 pmMy newest toy arrived the other day. It's displaying the dreaded YTO unlock error that is apparently common to the breed, but some online searching indicates that this is often a result of bad caps causing the YTO drive voltages to be out of spec. I'd initially wondered why the spec an section was made 'upside-down, but now realize that's so it can be operated on while both pieces are still attached to one another.Unfortunately, I need to deal with a broken ball joint on my friend's car tomorrow, so lord only knows when I'll get to this...Fun, fun!!!-PatAwesome! If you go search on youtube there are a couple of different people showing the repairs. I want to get a really nice 66B...I have a 66A but it's severely gimped in terms of GPIB functionality compared to the 66B. Yours looks to be in great shape! Thanks! I got it from an ebay vendor in New Hampshire that I've had good luck with. Their shipping, while not dirt cheap, is fast, and the items are very well packed.The video I watched the other night was put up by a guy named Kerry Wong. My fingers are crossed that this will be something relatively minor. I may need to do some monkeying with the display, too, as the text seems dim relative to the rest - I need to turn the brightness up to the point where the trace starts blosing out before the text shows up. I figure there is likely a balance or separate brightness control hidden in it somewhere that needs a tweak. Will need to dig further into the display before tweaking anything, though, so as not to knock things out of whack with ham-fisted twiddling. The YTO repair will be the first order of business, though.-Pat
Quote from: Cubdriver on September 27, 2019, 11:32:50 pmMy newest toy arrived the other day. It's displaying the dreaded YTO unlock error that is apparently common to the breed, but some online searching indicates that this is often a result of bad caps causing the YTO drive voltages to be out of spec. I'd initially wondered why the spec an section was made 'upside-down, but now realize that's so it can be operated on while both pieces are still attached to one another.Unfortunately, I need to deal with a broken ball joint on my friend's car tomorrow, so lord only knows when I'll get to this...Fun, fun!!!-PatAwesome! If you go search on youtube there are a couple of different people showing the repairs. I want to get a really nice 66B...I have a 66A but it's severely gimped in terms of GPIB functionality compared to the 66B. Yours looks to be in great shape!
My newest toy arrived the other day. It's displaying the dreaded YTO unlock error that is apparently common to the breed, but some online searching indicates that this is often a result of bad caps causing the YTO drive voltages to be out of spec. I'd initially wondered why the spec an section was made 'upside-down, but now realize that's so it can be operated on while both pieces are still attached to one another.Unfortunately, I need to deal with a broken ball joint on my friend's car tomorrow, so lord only knows when I'll get to this...Fun, fun!!!-Pat
"Jammy Git" -hp- 3400A. I did a rough adjustment as it was pretty far off (cal sealed and dated due in 2004 ). Still need to work on flatness over the passband, but it's usable now. Bonus absolutely gratuitous RPN porn just to tweak certain people who know who they are.
"Jammy Git" -hp- 3400A. I did a rough adjustment as it was pretty far off (cal sealed and dated due in 2004 ). Still need to work on flatness over the passband, but it's usable now.
Quote from: wch on September 27, 2019, 11:19:04 pmmed, what’s the sn on yours? mine is very early. i noticed the hat sink on yours is “manufactured” for example, while mine is clearly an addition.003983.
med, what’s the sn on yours? mine is very early. i noticed the hat sink on yours is “manufactured” for example, while mine is clearly an addition.
just to tweak certain people who know who they are.
Quote from: Addicted2AnalogTek on September 28, 2019, 12:09:55 amSomething in my 7854 has decided to take an occasional dump to ground, and I've only managed to notice because the case shocked me earlier. As far as I can tell, there's no other faults occurring when this happens. It's only a mild shock as one would expect from an otherwise functioning device. The fault exists regardless of what plugins I've got installed, so it's definitely in the mainframe itself. It does take around 30 minutes of operation before the fault manifests itself, and it's doing so fairly consistently. I've never had to track down a "mild" fault such as this. Anyone have any suggestions on how to tackle tracking down the bugger?The power supply voltages and ripple were good last I checked, but I'll be checking them again at startup and once the fault manifests.As for tracking down the fault to a particular board, I'm considering using a 7A22 in another mainframe with the negative input probe attached to the ground at the mains input and move the positive input probe around each board's ground test points to narrow the fault down to the board, then continue from there to find the bastard.Does anyone have any ideas?Am I reading this right? You're getting a shock off a supposedly grounded chassis? Correct?? If yes you need to determine why your scope isn't grounded. Is there a problem chassis to ground prong on the power plug? Or do you have bigger problems with the lack of a ground on your mains wiring? You need to figure this out first.I think, but not sure, that the EMI filter has capacitors in it tied between hot and ground. If you don't have the chassis grounded these caps could cause the chassis to elevate to a fairly high potential, sometimes as high as 80 to 90 volts. The current is real small but you might feel it. And if the caps are going leaky then the current will go up. And also this leakage current could damage other equipment. Be safe. If you are getting a shock off the chassis of your equipment something is seriously wrong and you need to shut it down and determine ASAP what's going on.
Something in my 7854 has decided to take an occasional dump to ground, and I've only managed to notice because the case shocked me earlier. As far as I can tell, there's no other faults occurring when this happens. It's only a mild shock as one would expect from an otherwise functioning device. The fault exists regardless of what plugins I've got installed, so it's definitely in the mainframe itself. It does take around 30 minutes of operation before the fault manifests itself, and it's doing so fairly consistently. I've never had to track down a "mild" fault such as this. Anyone have any suggestions on how to tackle tracking down the bugger?The power supply voltages and ripple were good last I checked, but I'll be checking them again at startup and once the fault manifests.As for tracking down the fault to a particular board, I'm considering using a 7A22 in another mainframe with the negative input probe attached to the ground at the mains input and move the positive input probe around each board's ground test points to narrow the fault down to the board, then continue from there to find the bastard.Does anyone have any ideas?
Quote from: 0culus on September 28, 2019, 03:12:14 amjust to tweak certain people who know who they are. Do not forget that you've also added an iteration of "firing bd137's desire for a 427A"; with that subtle inclusion in the just-enough-focus-to-identify background.
Nice collection there . Plenty of HP goodies
Ooooooooooh, I like it!Edit, here is some of my rpn stash, I have a 41C collection - printers, wand, plug ins. HPIB IF. Quite a few 41s with the battery connection roo**d but most work.
I wish I had my father's wooden sly-drool, it got tossed in the 80s unfortunately. But I have some of his circular calculators for fluids/gas - he was a civil engineer.
Nixiefreqq is gonna have a stroke when he sees all this.
Posing RPN twaddle is starting to look like the next Planking fad ....... Stop it before you go blind
I know it's a lost cause but at least put on a brave face before being shot down in flames.
I have dibs on b-f's gear, he is in the same country. But I am way too lazy to roast my own coffee - I will pass on that! "Enter"