| Products > Test Equipment |
| Old Fluke Multimeters |
| << < (175/192) > >> |
| drtaylor:
As far as I know, you could use all tantalums in the 8060. I don't think it will improve anything except perhaps in the charge pump. Tantalums are less forgiving for reverse voltage, so be very careful with polarity. I vaguely recall that a small amount of reverse voltage is possible at C19, but I could be wrong. As long as they are of adequate voltage, and they fit the pads, have at it. I built the original prototypes with a lot of tantalums and it worked fine. Wasn't worth the cost, except unless you expected to be using the 8060 30 years later. Who knew that would happen? I always use at least 5000 hr, 105degC rated Aluminums. If you put those in, the 8060 could easily last another 30 years. |
| helius:
--- Quote from: scopeman on March 02, 2022, 04:26:48 am ---How about Panasonic's OSCON Organic Aluminum Caps. Very low ESR. I have used them in high volume production with very good results. No failures or issues in 10 years of service in an industrial environment. --- End quote --- Solid polymer electrolytics have high leakage. Not ideal for measurement instruments. |
| precaud:
--- Quote from: drtaylor on March 05, 2022, 08:21:52 pm ---Hi to all 8060 fans! I have recently completed restoring and recapping 15 8060A Multimeters --- End quote --- A year or so ago you said you had some spare MAC IC's tucked away somewhere. Did you ever find them? I still have a couple 8060A's with bad MACs and could use a couple. |
| drtaylor:
--- Quote from: helius on March 08, 2022, 02:08:45 am --- --- Quote from: scopeman on March 02, 2022, 04:26:48 am ---How about Panasonic's OSCON Organic Aluminum Caps. Very low ESR. I have used them in high volume production with very good results. No failures or issues in 10 years of service in an industrial environment. --- End quote --- Solid polymer electrolytics have high leakage. Not ideal for measurement instruments. --- End quote --- Solid Polymer Capacitors actually perform better in most Electrolytic locations in the 8060A. Leakage does not come into play when the caps are being used in power supply filters and the charge pump. The charge pump in the 8060 performs better with polymers. The only place I would say that the leakage could possibly be an issue would be in the TRMS converter. Note, I'm referring to the original TRMS circuit designed by Fluke, not the later ones using an Analog devices chip. The AC output filter C17 is indeed in the signal path, but with a source impedance of less than 20k, the leakage would not cause a discernible error. C18 and C19 could also be affected by leakage. Also realize that Polymer Electrolytics leakage is measured at full voltage, and high temperature. I don't think you'd have an issue. That being said, low leakage standard aluminum electrolytics work fine in all the locations in the 8060A. I'd use polymers in the charge pump circuit as this does show some improvement at the noise floor. Still compared to the caps we had available in the early 1980s, current caps are superior, as long as you pick a reputable manufacturer. I tend to specify 105deg (or higher) 5000hr rated caps for reliability. So, while I do agree that Polymer Electrolytics should be avoided in the signal path of high resolution measurement equipment, you cannot make a blanket statement that they should be avoided. Just don't use them as a filter in a circuit with a high value source impedance. |
| caall99:
Hey all! Great thread and thank you all for the great contributions. I have recently bought 10 different 8000 series handhelds, and have a couple 8060s i am looking to recap. the 8060a multimeters I have are newer PCB revisions and all the test points show they are A-OK. Also, there are no signs of leaking electrolytic fluid, but I intend to replace all the caps either way. Unfortunately, MrModemHead's capacitor purchase list is now obsolete, as many of the components are no longer being manufactured. drtaylor, and co., is there a new purchase list? I am having trouble finding low profile capacitors, branded Rubycon or Nichicon that are actually in stock. Please let me know! |
| Navigation |
| Message Index |
| Next page |
| Previous page |