Testing the HP65 or HP67 card reader sense amplifier

[teenix]

(11-17-2021 02:03 PM)albertofenini Wrote:  I Tony,

I may as well unsolder those pins you are right

When testing write capability, where should I measure the output of the
signals that I have injected at WA and WB on the sense amplifier ?

Thanks and sorry to ask so many questions ...

Sorry, this might not have been clear on earlier post in the thread...

You can apply a 4-5V square wave of approximately 1KHz frequency on WA or WB and see what appears on the head coil outputs from the sense chip. (HA and HAC) and (HB and HBC)

No problems :-)

cheers

Tony