Icom R7000 - adding DSP

[N8YX]

Sounds like a nice job :)

Would the switch functions and audio in/out be available via the voice module header?

Unfortunately, no. That's what prompted the disassembly job. :(

The switch board has a 5V reference applied to a couple of its traces and the Speech switch must be isolated from these, as the ADSP2 unit requires a momentary ground on each of its control lines to properly select the various modes and bandwidths. The IC-EX310 Audio Input line is just that...an "input" to the audio preamp. The main-board audio signal chain must be broken in order to insert the I/O leads. Additionally, the volume-control pot on the front panel merely varies the gain of the AF preamp IC and cannot be used as an injection point.

Was all the effort worth it?

I parked the R7000 on 27.385LSB, activated the NR feature at 13dB level...then activated the audio filter with an "SSB" bandwidth setting. Things are eerily quiet until someone starts talking - and all you hear is their voice. Turn everything back "off" and they are either buried in QRN or their signal is neck-and-neck with it...which makes for very rough copy.

Though my DSP-599zx is a bit more flexible, I think the nod in terms of efficiency - at least in this application - goes to the SGC.

[mw0uzo]

The switch board has a 5V reference applied to a couple of its traces and the Speech switch must be isolated from these, as the ADSP2 unit requires a momentary ground on each of its control lines to properly select the various modes and bandwidths. The IC-EX310 Audio Input line is just that...an "input" to the audio preamp. The main-board audio signal chain must be broken in order to insert the I/O leads. Additionally, the volume-control pot on the front panel merely varies the gain of the AF preamp IC and cannot be used as an injection point.

Yes - working solutions are quite different to initial ideas, its amazing how many unanticipated hurdles are come across when developing a mod, program or solution to a problem!

I have yet to expeience any good DSP processing. I have probably been exposed to old generation AF dsp only, so it sounds like the later generation dsp is quite good. Must be good for you to consider putting it into your receivers. :)