HP-67 - 1612A03018 - Card Reader Advice Requested (was HP-67 - strange behavior)

[albertofenini]

We began some testing on the three card readers we have.

First we tried an HP65 style card reader, but we substituted the fixed resistor with a trimmer.
However, this is a noisy card reader, you will see that by just turning on the machine the channels
RA and RB were very disturbed and reading a card from the Standard PAC was not working.
However, from a mechanical point of view this card reader works fine also with blank cards
and with cards from an HP65 standard pac