Hi Tan, Just for fun... I put some SCRs on the curve tracer today. 10 matching pieces of an MCR72-6 had identical characteristics, the screen traces were so close to the same that you could not tell o

Hi Tan, I believe my recent tests on those SCRs were flawed, so I am busy trying to understand how to test them properly. Hopefully I will have a report on this soon. I have never used, or worked on t

Could I suggest that you do NOT buy your next Dallas chip on eBay? I bought some of them on eBay and they had clearly had the original markings sanded off, and new markings put on. The sanding was cro

Thanks for the partial schematic to look at, along with your question. I would change the 10 uF capacitor to start with. In my experience all of the capacitors between 10 uF and 100 uF are suspect in

Ooops! my mistake... I would change the 100 uF C1486 capacitor. tom jobe...

A look through an old Metcal price list shows that there are different models of the power supply for 120 volts and 240 volts. In the case of the Metcal MX500 power supply (my personal favorite) the 1

It's been my experience that any Allen key that is not an accurately ground hex is all but useless on these small set screws (the .050" and the 1/16" especially). The nice ground hex Allen tools they

Now that more replies have come in, I would second the vote to use some heat no matter what you do about a better tool. A hair dryer should work well, but it will take some time to get the aluminum kn

Hi Marcus, Thank you for the X-Rays of the 475 multiplier. I have often wondered what it looked like inside. Today I put a defective 465B multiplier in the milling machine to see how easy it would be

Hi Tom, I bet you are right about if being glass filled, rather than ceramic filled. The cutters died in that same "polished" sort of way you see when cutters are used on glass filled epoxy boards. In

Hi Tom, That is another great idea you have given us! The PCB board with solid copper on one side would work perfectly with the copper cleaned off around the connections. Lin Scott's idea about using

Hi Ed, I bet your plan of using the expensive milling cutters would work perfectly, but it would not be worth it when you added up the time and money you had in the project. I think I'm going to use s

Thanks Reed, What a shocking revelation this is for this amateur! The books I've seen only show the type of multiplier that uses one diode and one capacitor per multiplication stage. We need to see th

Now I'm really confused! How does 6 times 2450 get to 15,500? tom jobe...

Thanks Tom, Your honesty is refreshing! tom jobe...

Thank you Dave! Your schematic ties the whole conversation together. It amazing what we learn on Tekscopes. tom jobe...

My guess is that you will hear something rattling around inside the CRT once you have it out of the oscilloscope. Depending on the position the scope was transported in, it may also have scratches in

Joe, have you tried setting the Source switch to "Int" (for internal)?

The original part was a plastic piece with six plastic pegs on it. The part was held on to the metal cover by heating the ends of the pegs to "mushroom" them over. It was fragile at best, but it shoul

Allow me to add a missing piece to this drilling discussion. It is difficult to get good hole size with a normal drill bit for a variety of reasons. In the case of making the hole in a single pass wit