Re: 475M metal can caps


One thing Tektronix did a great deal was to only have one voltage supply with a zener reference, it's output was the reference for other voltage supplies. Sometimes there would be a cascade of supplies giving reference to others. Needless to say, if any one of them is not accurate and clean, the following ones won't be either. The absolute worst examples I ever dealt with were some Yamaha stereo receivers where one zener ultimately controlled cascaded power supplies producing nine different voltages.

Bruce Gentry, KA2IVY

On 11/6/20 5:27 PM, Paul Amaranth wrote:
I will second Michael's recommendation. The little adapter boards make
for a very neat and professional looking repair. In a pinch I've used
PNP blue to etch my own, but it's easier to buy them ready made.

Use 105C caps if you can.

On these scopes if the power supplies are not right, nothing works right.
Always ensure the power supplies are correct before looking at anything


On Fri, Nov 06, 2020 at 10:15:53AM -0800, Michael W. Lynch via wrote:
I have restored several of this family of scopes. Finding OEM style caps that are good is not a really viable option.

I use Modern radial lead caps and these adapters:

I would say that you have issues with you -15 and -8V Supply. Caps may help rectify some of those issues. A Good place to start in any case. Get you supplies back in spec and you will go a long way to fixing the scope.

Good Luck!
Michael Lynch
Dardanelle, AR

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