I am using a Motorola DSR-550, a non-deactivated ex-VOOM terminal as a converter box. It was disconnected from the power at the time VOOM sent the kill signal over the network.
Unfortunately, the DCT-2000 is a QAM-only tuner. If you're shopping for a tuner that is different from CECBs, it has to handle ATSC signals. Some of these tuners that handle OTA ATSC signals, in addition to a subscription signal, might have a firmware requirement to have a valid subscription connected, before the tuner will let you have access, so be sure to check against that.