[GreenKeys] TU-170 Analysis

[Harold Hallikainen]

I've started an analysis of the circuitry of the TU-170, especially the
demodulator. It's at https://w6iwi.org/rtty/tu170/spice/ .

My next step is to cascade three mark band pass filters and see what looks
like. On my DSP TU, I'm going to add constants that determine the Q of the
BPFs and the number of filters cascaded, then try running audio through to
see how it performs. I have recorded impaired audio at
https://w6iwi.org/rtty/audio/ .

Comments welcome!

Harold
https://w6iwi.org