21-10-2021, 09:15 AM
(This post was last modified: 21-10-2021, 09:19 AM by Murphyv310.)
Hi.
Here are some test photos off the scope.
The frequencies used were 100hz, 1khz and 10khz. Response is pretty flat from 60hz to 8khz, slight tail off at 10khz and below 40hz.
The trapezium was at 1khz and with a 1566khz carrier. Also shown is the waveform at 100% modulation and 150% modulation.
It's interesting to note that the oscillator runs with a crystal marked at 42.5 Mhz with excellent sound on a 405 line telly!!
Here are some test photos off the scope.
The frequencies used were 100hz, 1khz and 10khz. Response is pretty flat from 60hz to 8khz, slight tail off at 10khz and below 40hz.
The trapezium was at 1khz and with a 1566khz carrier. Also shown is the waveform at 100% modulation and 150% modulation.
It's interesting to note that the oscillator runs with a crystal marked at 42.5 Mhz with excellent sound on a 405 line telly!!
