-> Most cool, even if it has been used as a training device for -> ET's :^) Now -> you just need a AN/UYK-7 computer! -> -> Zane -> Around 1977-1979 the personalized Virginia license plate on my 1955 Ford Crown Victoria was UYK-7. Nice Univac machine, for a military unit. I still have the license plate around here (somewhere). Bill

At 09:06 PM 4/24/00 -0700, Kird Davis wrote: Au Contraire mon ami! It means now I need a PDP-12 to put the whole family together :-) Not that its all that likely that I'll find a -12. Still waiting to hear the press release from the company that bought all of John's machines. --Chuck

Now, now. I have one. At one point it was working almost perfectly. I had to fix one board and figure out a terminal interface for it, until I got lucky later and scored a current-loop interface board. I had to reform the capacitors in the power supply at one point, after blowing out the big bridge rectifier. I don't see that it would be worse (or better) than anything else of that vintage. At one point it was working just fine. Currently it is mostly working, but will not boot -- but I don't have time to fix it right now. Jay Jaeger At 06:50 PM 4/25/00 +0100, you wrote: --- Jay R. Jaeger The Computer Collection cube1(a)home.com visit http://members.home.net/thecomputercollection

Upon the date 01:10 PM 4/25/00 -0700, Dwight Elvey said something like: Use 15k to 30k at minimum 5 watts. Using Ohm's Law, figure the current throught the resisitor. A rule of thumb I found shows for capacitance value 6000 MFD and higher at 25 working volts figure a limit of 8 milliamperes leakage current (0.008 amps) before planning on replacing them. This is even after reforming them using your step-increase plan depicted above. Rough test but sort of okay to get a ballpark idea of condition. Uh, "as having low capacitance on the ohm meter" ?? Only thing you'll get a real hint of is whether the cap is rather leaky or not. No close relation to capacitance value measurement except that for great step increases in capacitance (say, from 1000 to 10000 MFD for example) you'll get a very rough idea of value just from time to charge. Then only if the cap is very leaky would you see a difference between caps of same capacitance value. And even this idea is not reliable because the variation in capacitance value for same-marked caps can be up to +100% for the cheap grade and maybe +20% or more for the "computer grade" caps. I've got a writeup I quickly tossed together which I posted to a couple of members of the Boatanchors List (boatanchor == affectionate term used for any radio which is used for commercial or amateur radio reception or transmission which is big, heavy and uses vacuum tubes (valves)). This writeup discusses capacitor leakage testing and electrolytic reforming on our beloved boatanchors. Similar application to the electrolytics and a few other capacitors used on the old computers we all love on this list. I can send a copy to others here who may be interested. Just email me with the request in the Subject line. Indeed, but the silicone grease is only the vehicle for the tin oxide (or zinc oxide) filler which does most of the heat transfer. If left undisturbed there should still be virtually all the orginal thermal transfer capability as when the unit was built. But, I've not studied the effect of the loss of the silicone grease too much. Tony, have you seen much variance here in your experience? Power line input filters? Tantalums?? On the AC mains??! No wonder they let loose as any reverse voltage above a low tolerance level on any tantalum will short them and they go boom! Not a pretty picture sometimes. In this case I would say that they were not tantalums but something else such as a Mylar film dielectric cap or some such. Since they blew up I would guess they had gotten nailed with lightning or a significant power line surge which punctured the dielectric and shorted them. Later, when the unsuspecting fellow at Stan's applied power, perhaps for the first time after the damaging incident, he got the surprise. Regards, Chris -- -- Christian Fandt, Electronic/Electrical Historian Jamestown, NY USA cfandt(a)netsync.net Member of Antique Wireless Association URL: http://www.antiquewireless.org/

Hi all, Correct, this is what I had to rebuild a peecee PSU switcher with new caps. Now good as new. Very good meter, but it also can measure .01 to 99 ohms resistors. Which is very useful especially when one wants to check low current contacts is low resistance enough and works reliably. Usually greater than 6ohms in contacts makes the device behave strangely. Even 10 ohms on nicked 10cm long trace is enough to cripple the peecee motherboard, had to splice it to decrease this resistance. And this is great device for checking fusiable resistors in circuit usually for opens or partial opens because it's voltage output is lower than junction therhold. I just fixed a Apple ][e PSU, 220uF 10V ESR in PWM circuit went skyhigh and I didn't pull any caps to check thanks to the ESR meter and job took 30 minutes start to end. That was last week, that faulty cap looks same as other caps in same PSU visually. Dick Smith Electronics sells this ESR meter and is designed by Bob Parker. My other kit-built DMM can't zero'ed out when I need to mesaure very low resistances <3 Ohms, the ESR meter comes out for this. Wizard