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Equipments 1
Frequency
Counter LS-223 ( Home made )
[Outline]
[Front
view] [Top view]
[Bottom
view] [Block diagram]
Fig.1 Nixie tubes. The left two are CD71(Hitachi) and the right two are
CD78S(Panasonic).
In my high school days, 7 segments LED display is expensive for me.
Someday I transfered
some 2nd hand nixie tubes ( CD78s Panasonic ) from a local amature
radio station,
which had removed from an old electrical calculator. So I used these
nixie tubes
and the driver ICs ( SN74141N ) for this counter. After few years,
CD78S intensity
were going low, so I had to look for the new ones. At a parts shop
"DIGIT"
in Nippon-bashi, Osaka, there were some nixie tubes ( CD71 Hitachi ). I
bought them
and replaced.