Is anyone of the regulars in urgent need of Tek ground leads with the tubular connector (such as used with the P6122, P6131)?
Is anyone of the regulars in urgent need of Tek ground leads with the tubular connector (such as used with the P6122, P6131)?
Yes, actually. I could use four of them...
A long and sorry saga, how hard can it be to fix a 12MHz counter with discrete 7 series logic ?
Isn't it a factor that older equipment often fails in quite creative ways, with some components aging more gracefully than others... transistors that nearly have enough gain, resistors that almost have the right resistance, capacitors that almost have the right value, IC gates that get so close to pulling its line up high enough, a power supply that is almost quiet enough, decoupling components that are almost good enough, that kind of thing...
That is so true here, the old transistor had a hFE of 10 or so, I think the 7400 was also loading too much as well.
I think you learn so much when repairing, not only about electronics but also perseverance and how not to hit people or things.
Fuck it. I forgot to bid on these earlier
I had the hp on top, lots of gold traces in that one. Would like to obtain a nixie unit too when I can.
Oh, I have a almost mint 3478A complete lead acid battery and I love it. To borrow a phrase from med, it's dead nuts too. It's so handy as I can use without having to power up the stack[emoji16]
Sent from my POT-LX1 using Tapatalk
OK, I've been in denial and have not been to my TEAA meetings as often as a should have but my 'MALFUNCTION!'ing Druck Unomat TRX is proving to be a bit of a pig to get working, does ANYONE have a schematic or service manual for this or is it, as I suspect, kept in a secret vault on the dark side of the moon?
I found this gem today which I'll share...
I'd like to make the world a better place but they won't give me the source code.
If you find that secret vault please let me know because I have no idea what a "Druck Unomat TRX" is supposed to be or look like. Perhaps a pix or two so if I happen to trip over one I'll know what it is.
But right now all I can give you is a dumb deer in the headlights look.
I was looking for a new handheld multimeter. Was initially thinking of buying a Fluke 87 Since I wanted better accuracy and digits.
But since the Fluke 87 are still pretty expensive, I ended up finding a way better deal with a HP 974a. I didn't really know about those meter and found it on ebay by accident. Specs are pretty good (4.5 digits, 50000 counts, 0.05% accuracy) and it's in pretty good shape. The unit I have was calibrated in 2018 and is due in 2021. I'm pretty happy with my purchase.
I found this gem today which I'll share...
I'd like to make the world a better place but they won't give me the source code.
It is being reverse engineered as we speak.
And we (Venter actually!) are adding new syntax to the language
@Kosmic - Neat find on that 974A... I especially like the "dumbass-resistant" current jacks...
Pretty error proof. You can only open the amp shutter in amp mode
The 465B/DM44 is back together. Powered up first try no issues. The +55V reference is sitting at +55.04V which is perfect. No adjustment required. All supply voltages in spec. And best of all, no ripple on the traces. Nice and sharp. But there's still an issue. There's an identical roll-off on both channels as seen here. I didn't think replacing the PSU caps would fix this and that proved to be correct. The issue is not the attenuators, the B/W limit switch, nor the pre-amp board (It's been changed). So the prime suspect is the Vertical Output board. I do have a spare board and I could just change it out but I'd rather try to identify and fix the issue. So this will be an excellent opportunity to put the 485 to work. Which BTW has been on the torture rack for the past week and a half and running perfectly with no issues. So stay tuned, obviously I'll post what I find.
I ended up finding a way better deal with a HP 974a.
Oh dear, is it RPN?
No, unfortunately since the device mostly measure and doesn't do much calculation. (It's a multimeter
)
The 465B/DM44 is back together. Powered up first try no issues. The +55V reference is sitting at +55.04V which is perfect. No adjustment required. All supply voltages in spec. And best of all, no ripple on the traces. Nice and sharp. But there's still an issue. There's an identical roll-off on both channels as seen here. I didn't think replacing the PSU caps would fix this and that proved to be correct. The issue is not the attenuators, the B/W limit switch, nor the pre-amp board (It's been changed). So the prime suspect is the Vertical Output board. I do have a spare board and I could just change it out but I'd rather try to identify and fix the issue. So this will be an excellent opportunity to put the 485 to work. Which BTW has been on the torture rack for the past week and a half and running perfectly with no issues. So stay tuned, obviously I'll post what I find.
You could test that hypothesis by connecting the output on the rear panel to another scope. If that looks OK the the vert CRT driving board is the problem. Are there tweaks on it?
[Oh, I have a almost mint 3478A complete lead acid battery and I love it. To borrow a phrase from med, it's dead nuts too. It's so handy as I can use without having to power up the stack[emoji16]
I have the 3438A, and I love it! Quite accurate, to my (non-volt-nut) standards, at least.
Having more multimeters always is a big win.
Yeah, the 3478A is as "volt-nut" as this tinkerdwagon is ever gonna get in this lifetime...
mnem
*back out into the suck*
I had the hp on top, lots of gold traces in that one. Would like to obtain a nixie unit too when I can.
Oh, I have a almost mint 3478A complete lead acid battery and I love it. To borrow a phrase from med, it's dead nuts too. It's so handy as I can use without having to power up the stack[emoji16]
[/quote]
I have 2 myself of these also and paid less than $100 US for each one of them. Very nice meters.
I was looking for a new handheld multimeter. Was initially thinking of buying a Fluke 87 Since I wanted better accuracy and digits.
But since the Fluke 87 are still pretty expensive, I ended up finding a way better deal with a HP 974a. I didn't really know about those meter and found it on ebay by accident. Specs are pretty good (4.5 digits, 50000 counts, 0.05% accuracy) and it's in pretty good shape. The unit I have was calibrated in 2018 and is due in 2021. I'm pretty happy with my purchase.
I just searched evilBay for one and all that comes back are magenta pagewide ink cartridges
Fucks sake. My T440 just blew up. Looks like the mains adapter had a blow out and took the laptop with it. Gahhhhh bastard!