With a 24x5[AB], I'd presume the battery backed RAM had lost its calibration constants.
With a 24x5[AB], I'd presume the battery backed RAM had lost its calibration constants.
Yes, but isn't that just "some" elbow grease?
I'm also quite sure I've changed some Dallas chip or the like batteries by just popping the top open.
No idea though what could be a current status of any of those kinds.
Dallas chip is mechanically quite big.
Still no flash + super cap replacements?
Yep, with enough persistence you can take the top that holds the battery off the Dallas chips and connect a fresh lithium battery.
Yep, with enough persistence you can take the top that holds the battery off the Dallas chips and connect a fresh lithium battery.
IIRC that is easier with some modules than others. I intend to avoid doing it
Calling all people with a National Instruments ISA GPIB-PCII/IIA GPIB card and a chip reader!
Seems my faulty card is maybe, possibly, likely due to a failed GAL16V8D. I think if someone could read out theirs and give me the file, I might be able to reprogram this chip, or a new one and maybe get this card working again...
Mine is a Rev 2.1 board with the big NAT4882D chip, not the VLSI chip. Unfortunately my other cards aren't the same revision, so the GAL image won't work..
My morbid curiosity wonders how much of an improvement replacing all those carbon composite resistors with 1% 50ppm metal films will have on stability?....Hopefully, the output stability won't depend in any significant way on the performance of the carbon composition resistors. There ought to be only metal film or wire-wound resistors in the critical parts of the circuitry that determine the calibrator accuracy.
This a Tek 7504 scope.... from my big TE haul from a few months ago.
It's a parts unit in extremely poor shape... so finally yesterday I took it to bits to salvage what I could from it... not much that is, it's too far gone...
Calling all people with a National Instruments ISA GPIB-PCII/IIA GPIB card and a chip reader!
Seems my faulty card is maybe, possibly, likely due to a failed GAL16V8D. I think if someone could read out theirs and give me the file, I might be able to reprogram this chip, or a new one and maybe get this card working again...
Mine is a Rev 2.1 board with the big NAT4882D chip, not the VLSI chip. Unfortunately my other cards aren't the same revision, so the GAL image won't work..
@Vince: can you salvage the current clamp calibration fixture?
This a Tek 7504 scope.... from my big TE haul from a few months ago.
It's a parts unit in extremely poor shape... so finally yesterday I took it to bits to salvage what I could from it... not much that is, it's too far gone...
Back in the day TEA - when gear had real power switches!
Annddd, now I have a Tek THS720 (with carry bag and charger) on the way... It has the usual burnt polarizer on the LCD, but it seems to work according to the pictures in the listing.
I'll upgrade it to a THS720P and update the firmware if needed. Might even try and see if the TDS210 to TDS220 upgrade hack (Tell the scope it is the higher model then run the appropriate adjustment routine before rebooting it) will work to upgrade this THS720 to a THS730. ([EDIT] Just looked at the schematics, might be a case of swapping resistors and maybe one or two other parts to make the upgrade)
Probably end up doing the LED backlight mod, and building a new battery pack while I have it in pieces.
Will be handy for working on the car and for the youtubes, easier to lay on the bench under the camera than the TDS220..
Should provide a few hours of fun giving it a bit of love on the healing bench.
I'm using the cards in PCIIA mode, but that shouldn't affect things too much..
...snip...
As for my QUAD 33/303 pair, it's still not finished I am afraid... I tried to order the trannies and cheap 1 buck 4 pin DIN connectors I need, along with the light bulbs for my Tek 7603 all in on order. No luck. Spent a lot of time checking several sites but no one seller had all of these items, never mind in stock. Resorted to checking Digikey and Mouser, and splash 50 Euros with them... still no luck.
So I am so upset and bored and fed up with this repair taking forever...that I have now got used to the idea of spending 10 Euros of shipping to buy the trannies in one place, the DIN connectors in another place, and give up on getting the bulbs altogether. 2 out of 3 work and the scope is usable as is, so no emergency there, especially since it's not my daily driver.
So yeah, I need to order these freaking trannies and DIN connectors this week if I want to push these amps out the door at long last....
Before I get rid of them I will try playing some music through them just in case I like it. So far I have only tried them with a tone from my sig gen.