02-04-2020, 09:24 PM
What I didn't tell you was that it didnt play back very well. it was hard to tell because the tapes I have are four track stereo and all I hear is a garbled backwards sound.
Another reason it didnt play back too well was because of the layer of rust and dirt on the head, I had cleaned it with IPA when I got the recorder but it needed a soft wire brush on the dremill to make it shiny.
I've spent hours tracing and c hecking the circuit through but it records now - just needed cleaning, doh. Thanks for the useful suggestions anyway.
bias coil resistance 4.0R, 5mH
signal coil resistance 47R, 110mH
Aparentley you need to degaus after using a meter to make such measurements.
I have a tape head demagnetizer from years back fortunatley.
Perhaps a bit of a polish with some rouge next.
Kind regards, David.
Another reason it didnt play back too well was because of the layer of rust and dirt on the head, I had cleaned it with IPA when I got the recorder but it needed a soft wire brush on the dremill to make it shiny.
I've spent hours tracing and c hecking the circuit through but it records now - just needed cleaning, doh. Thanks for the useful suggestions anyway.
bias coil resistance 4.0R, 5mH
signal coil resistance 47R, 110mH
Aparentley you need to degaus after using a meter to make such measurements.
I have a tape head demagnetizer from years back fortunatley.
Perhaps a bit of a polish with some rouge next.
Kind regards, David.
