RolandK and 33 Guests are viewing this topic.
Quote from: med6753 on May 30, 2020, 02:51:42 pmQuote from: bd139 on May 30, 2020, 02:43:56 pmBench power supply / supplies and a Suitable current limiting resistor. They can have 20v drop across them easily. Measure V across diode to get voltage drop and measure V across R to get whether or not the diode is fucked.OK, what size current limiting resistor should I start with?I would work on current first so stick a 1k resistor and ammeter in series and slowly ramp up the supply voltage until it reads 2mA or so in the right direction. It probably won’t do a lot until at least 10-20V. Try it on a good diode first to make sure it works.
Quote from: bd139 on May 30, 2020, 02:43:56 pmBench power supply / supplies and a Suitable current limiting resistor. They can have 20v drop across them easily. Measure V across diode to get voltage drop and measure V across R to get whether or not the diode is fucked.OK, what size current limiting resistor should I start with?
Bench power supply / supplies and a Suitable current limiting resistor. They can have 20v drop across them easily. Measure V across diode to get voltage drop and measure V across R to get whether or not the diode is fucked.
Quote from: mnementh on May 30, 2020, 03:05:50 amI’ve found this as well, but the last time I said anything to that effect I got dogpiled for using/suggesting folks use “contaminated” IPA. So now I just keep my mouth shut, and keep a spray bottle of each on the bench. mnem Oh no, are you feeling feverish, have a headache, loss of taste and smell? You must be suffering from CVD19 (sounds of a klaxon horn going off to alert everyone). This is not the mnem that all know and love, can't be, keeping mouth shut Get well soon please old buddy, its discord day today
I’ve found this as well, but the last time I said anything to that effect I got dogpiled for using/suggesting folks use “contaminated” IPA. So now I just keep my mouth shut, and keep a spray bottle of each on the bench. mnem
I've always remembered and applied a concept from James Clavell's "Noble House". A character in that novel, a lady executive has the objective to have “drop dead money”. The “drop dead money” is that amount of money that she calculates she needs so that she would have the freedom and the luxury to tell anyone to “drop dead” without worrying about her financial security.
Quote from: Kosmic on May 30, 2020, 01:11:46 pmQuote from: Specmaster on May 30, 2020, 12:41:00 pmToday I did the hot air gun repair to the 4503 meter and I'm very pleased to report that it worked a treat, suspect joints that under a microscope appeared to be flawed on the component side of the board (2 layer board) where perfect on the solder side and after treating the top of those joints with rosin and gently warming with the hot air gun, the joints flowed nicely. However, there were 2 slight casualties, 2 polyester caps 22nF each used as HF filters had their outer cases slightly blistered, but still work OK. I'll get these replaced soon with new ones arrive.The residual 9Meg that resistance ranges were seeing has now completely been cured and the meter calibrated and is in complete agreement my other meters, "winner winner chicken dinner" as Dave would say. The photos below show it in resistance range with open leads and also measuring 4 x 10M resistors soldered together quickly to test the meters capability. You can use Kapton tape to shield surrounding components.Yes I could, I have some but the caps were some of the suspected bad joints that I needed to reflow from the top side and no way of getting on iron tip in there without actually touching them and other items.
Quote from: Specmaster on May 30, 2020, 12:41:00 pmToday I did the hot air gun repair to the 4503 meter and I'm very pleased to report that it worked a treat, suspect joints that under a microscope appeared to be flawed on the component side of the board (2 layer board) where perfect on the solder side and after treating the top of those joints with rosin and gently warming with the hot air gun, the joints flowed nicely. However, there were 2 slight casualties, 2 polyester caps 22nF each used as HF filters had their outer cases slightly blistered, but still work OK. I'll get these replaced soon with new ones arrive.The residual 9Meg that resistance ranges were seeing has now completely been cured and the meter calibrated and is in complete agreement my other meters, "winner winner chicken dinner" as Dave would say. The photos below show it in resistance range with open leads and also measuring 4 x 10M resistors soldered together quickly to test the meters capability. You can use Kapton tape to shield surrounding components.
Today I did the hot air gun repair to the 4503 meter and I'm very pleased to report that it worked a treat, suspect joints that under a microscope appeared to be flawed on the component side of the board (2 layer board) where perfect on the solder side and after treating the top of those joints with rosin and gently warming with the hot air gun, the joints flowed nicely. However, there were 2 slight casualties, 2 polyester caps 22nF each used as HF filters had their outer cases slightly blistered, but still work OK. I'll get these replaced soon with new ones arrive.The residual 9Meg that resistance ranges were seeing has now completely been cured and the meter calibrated and is in complete agreement my other meters, "winner winner chicken dinner" as Dave would say. The photos below show it in resistance range with open leads and also measuring 4 x 10M resistors soldered together quickly to test the meters capability.
Incoming, hopefully arriving soon is another AVO model 8, Mk5, complete with all leads, manual and also a clamp on amp probe, a bit grubby but it will clean up nicely. Seller is a retired electrical engineer having a clear out to save his son from having it to do when the time comes, in other words a pre SK sale. This will bring my tally of Avo model 8's upto 3. It wont get used all that much, but at the price it would be rude not to and I'm sure that one day these fine lovable meters will escalate in value. The attached photo is not actual meter, but it is however the same.
Quote from: tggzzz on May 30, 2020, 02:26:09 pmI've always remembered and applied a concept from James Clavell's "Noble House". A character in that novel, a lady executive has the objective to have “drop dead money”. The “drop dead money” is that amount of money that she calculates she needs so that she would have the freedom and the luxury to tell anyone to “drop dead” without worrying about her financial security.Financial independence is something often discussed with friends. It can be a difficult balance. It's tempting to work towards the drop dead point with all your might except that if you were to drop dead beforehand, it's been all for nought and you may not have spent your time wisely. Finding the balance between now and future can be a challenge, although not continuously dealing with the now due to a lack of resources or unwise use of available resources is a great first step.
The Fluke 8125A .. looks pretty nice for age... not sure but from the 70's like me... omg that 50 years??https://youtu.be/ko6Quk2e-F8Yes i did open it.. )
Yep windows 7 is quite frankly “fucking horrid” now.
Quote from: Mr. Scram on May 30, 2020, 02:04:03 pmQuote from: bd139 on May 30, 2020, 10:59:28 amMy first law is simply: time is the only currency worth considering.I've found that having some other currencies massively helps with having a say over the ultimate currency, although you can easily get lost gathering those other currencies.I've always remembered and applied a concept from James Clavell's "Noble House". A character in that novel, a lady executive has the objective to have “drop dead money”. The “drop dead money” is that amount of money that she calculates she needs so that she would have the freedom and the luxury to tell anyone to “drop dead” without worrying about her financial security.
Quote from: bd139 on May 30, 2020, 10:59:28 amMy first law is simply: time is the only currency worth considering.I've found that having some other currencies massively helps with having a say over the ultimate currency, although you can easily get lost gathering those other currencies.
My first law is simply: time is the only currency worth considering.
Yes, it's Saturday. I'll be on Discord at approx 2130 UTC.
Quote from: Ero-Shan on May 30, 2020, 01:56:28 pmAnd for those thinking that those drawers contained nothing but crap, one held these gems inside: I even have an idea where to store the remaining 6 cabinets. Fuuuuuuu... That's a £1000 worth of AD549s! (Where's the gobsmacked emoji?)
And for those thinking that those drawers contained nothing but crap, one held these gems inside: I even have an idea where to store the remaining 6 cabinets.
Quote from: bd139 on May 30, 2020, 02:57:18 pmQuote from: med6753 on May 30, 2020, 02:51:42 pmQuote from: bd139 on May 30, 2020, 02:43:56 pmBench power supply / supplies and a Suitable current limiting resistor. They can have 20v drop across them easily. Measure V across diode to get voltage drop and measure V across R to get whether or not the diode is fucked.OK, what size current limiting resistor should I start with?I would work on current first so stick a 1k resistor and ammeter in series and slowly ramp up the supply voltage until it reads 2mA or so in the right direction. It probably won’t do a lot until at least 10-20V. Try it on a good diode first to make sure it works.OK, thanks. In order to get those two HV boards out to check the resistors I have to unsolder all that wiring.
Quote from: med6753 on May 30, 2020, 01:51:06 pmYes, it's Saturday. I'll be on Discord at approx 2130 UTC. I'll do my best to be there and harangue you as usual, buddy. I know how you need your regular dose of aggravation to feel alive. mnem
Why not just current limit the source?
Cleaning, cleaning, cleaning ...
Quote from: med6753 on May 30, 2020, 03:06:39 pmQuote from: bd139 on May 30, 2020, 02:57:18 pmQuote from: med6753 on May 30, 2020, 02:51:42 pmQuote from: bd139 on May 30, 2020, 02:43:56 pmBench power supply / supplies and a Suitable current limiting resistor. They can have 20v drop across them easily. Measure V across diode to get voltage drop and measure V across R to get whether or not the diode is fucked.OK, what size current limiting resistor should I start with?I would work on current first so stick a 1k resistor and ammeter in series and slowly ramp up the supply voltage until it reads 2mA or so in the right direction. It probably won’t do a lot until at least 10-20V. Try it on a good diode first to make sure it works.OK, thanks. In order to get those two HV boards out to check the resistors I have to unsolder all that wiring. Update....and QService in Greece has 7 of them in stock in case they are bad....or I fubar them.
Quote from: bd139 on May 30, 2020, 02:43:56 pmBench power supply / supplies and a Suitable current limiting resistor. They can have 20v drop across them easily. Measure V across diode to get voltage drop and measure V across R to get whether or not the diode is fucked.Yup. That's because they aren't really a single diode, but a long chain of them encapsulated in epoxy. mnem
Quote from: Ice-Tea on May 30, 2020, 03:43:41 pmWhy not just current limit the source? mnem
Quote from: Cerebus on May 30, 2020, 02:51:33 pmQuote from: Ero-Shan on May 30, 2020, 01:56:28 pmAnd for those thinking that those drawers contained nothing but crap, one held these gems inside: I even have an idea where to store the remaining 6 cabinets. Fuuuuuuu... That's a £1000 worth of AD549s! (Where's the gobsmacked emoji?)Page 1140: https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/28475/Here ya go, C: mnem"Very helpful... very helpful indeed." Chibila thought to himself...
QuoteQuote from: Ice-Tea on May 30, 2020, 03:43:41 pmWhy not just current limit the source? mnemI either said something incredibly stupid or I produced the Columbus' egg. I honestly can't figure out which one from your reaction