Thanks Mat and all you guys much appreciated .... I don't know how to repay ...but first I shall keep probing.
I've got the unit filleted on my bench and found the audio( using the 25Khz harmonic "Marker" which I hear on CW) in around the AF UNIT ...so I think it leaves to monitor board ...the Marker signal gets converted to the side-tone which is I hope fine for signal tracing.
I 'm stuck in there between Monitor Pot and where it returns...I've down loaded a few schematics and board layouts from this groups.io FT-980- Technical manual?
73,
David VE3DPC
