Hello all,
Trying to get a period correct Panasonic RQ309AS to work with my newly built Gen2 Improved ACI.
Followed Uncle Bernie's instructions, one thing I did different:
- at the component side I put a 0.01 uF ceramic disc to make it look authentic
- at the solder side I put a 0.1 uF in parallel with this ceramic disc (reliability improvement)
Furthermore I followed the test procedure of the LM4040 with a lab power supply, all voltages were OK.
I fiddled around with the voltage level of the recorder, I can not make it read from tape (either C100R or C500R). Writing to tape seems to work, I get a '/' after writing and when I play the tape I hear the start tone and after that the 'bits'. When trying to read back I can see the LED light up, but I never get a '/' to indicate it finished reading.
Of course I am not sure the cassette recorder is OK. Have to try another one, but don't have one at the moment. I cleaned the heads. Maybe the extra cap is not the way to go, but as caps in parallel add up to each other it is not a big difference in capacitance, right?
Anything I could measure or check? Maybe the voltage level of the output of the cassette, so I can tune the voltage level by measuring? Thanks!
Regards,
Bobby
I suggest you use a modern playback device on a prepared audio file that has been successfully used by others; you need to bisect your problem to narrow down the object of troubleshooting.
There is no significant difference between 0.1µF and 0.11µF, but the type of capacitor can matter a great deal. Some types have high enough ESR to change filter characteristics, and some change significantly with bias voltage. It would have been better to A/B test the setup before changing its circuit.