Panasonic 805 Calculator

From: Rick Bensene <>
Date: Sat Dec 18 13:32:39 2004

This calculator definitely uses Vacuum Fluorescent (VF) display tubes.

The problem could be the VF tube itself, but not likely. The more likely
problem is
the digit driver. In this particular calculator, I believe that there were
driver transistors for each digit (and for each segment). If some of the
digit driver
transistors gets weak, the display can exhibit strange behavior.

The issue is back tracing the tube to its associated digit driver, then
the type of transistor (PNP or NPN, silicon or germanium), and general specs
(beta, and voltage/current rating)
and find a suitable current-day replacement.

Another option -- get another example of the calculator. The following was
on eBay for $9.99 last week, and didn't
It looks VERY nice, with original carrying case.

You might be able to contact the seller and make a good deal on it.

Rick Bensene
The Old Calculator Web Museum
Received on Sat Dec 18 2004 - 13:32:39 GMT

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