Friden EC-130 Help

Kyle Owen kylevowen at
Mon Feb 2 07:39:00 CST 2015

On Sun, Feb 1, 2015 at 11:03 PM, drlegendre . <drlegendre at> wrote:
> Likewise, I have no service documentation for it. But if I can be of any
> assistance, so far as providing voltage / resistance / component readings,
> I'll try to do my best as time allows.

Thank you! That will likely be very helpful. I am first going to check the
ripple on the capacitors, as I noticed some waviness in the display.
Perhaps one or more of the electrolytics isn't filtering as well as it did
50 years ago. I did bring it up over the course of several minutes on a
variac; I didn't notice any unusually high currents, and both fuses
remained unbroken. I'd say it's promising!

> They are fascinating machines - all the more amazing, considering that they
> were almost entirely designed by a single engineer.. save the analog /
> display portions, as I understand it.

Yes, it's quite amazing that with fewer than 200 transistors, as well as a
multitude of diodes, resistors and capacitors (and a delay line, of course)
that a 4-stack 4-function RPN calculator could be made.


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