Heh, good idea!
Minor hardware mod involving the crystal, disable the TX completely and use the (thus freed up) RX portion as a software defined radio centred on the 1 GHz band.
It would probably work natively too, have its CPU compress the raw data and hand off to Pi vian GPIO over the front panel LEDs.
Might have a go at this when my DG834Gs finally get annoying enough, up to 4 nuke-and-pave so far
and replacement 8 pin ADSL baseband chips because the lightning keeps frying them.