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Simon_V · 2nd Apr 2018, 7:11 pm

I might have cracked this I think. Given that the circuit diagram on page 145 of the manual has errors it would seem reasonable to assume that the PCB layout is also wrong. As far as my research goes the CML chip is an industry standard and just about all producers of CTCSS encoders follow their design. It does not seem reasonable to assume that Trio would choose to depart from this as they would have had to have the CML part re-masked to suit.

The forum will not let me post the two truth tables properly formatted so they are readable but I will report back when I have tested my theory which is just transposing outputs.

2nd Apr 2018, 7:11 pm	#3
Simon_V Retired Dormant Member Join Date: Feb 2014 Location: Pembrokeshire, UK. Posts: 52	Re: Trio TS711 & 811 I might have cracked this I think. Given that the circuit diagram on page 145 of the manual has errors it would seem reasonable to assume that the PCB layout is also wrong. As far as my research goes the CML chip is an industry standard and just about all producers of CTCSS encoders follow their design. It does not seem reasonable to assume that Trio would choose to depart from this as they would have had to have the CML part re-masked to suit. The forum will not let me post the two truth tables properly formatted so they are readable but I will report back when I have tested my theory which is just transposing outputs.