It should be, assuming your DVD/VCR has recording capability on the VHS side (some combo units record on DVD only). Set your converter box to the digital (standard-res digital, not HDTV) channel you want to record, attach the RCA cables (red/white/yellow) from the converter box to the VCR's input jacks (not the similar-looking output jacks), set the VCR for line-in input (sometimes this is done using the channel selector, sometimes with a separate control), and it should work. You can also use the coaxial output from the converter box and send it to the cable input on the VCR, and set your VCR's analog tuner to channel 3 or 4 (whichever you don't get over the air where you live - both the VCR and converter box will probably need to set to know which channel to use - 3 is more common), but the quality won't be as good. You probably will also need to change the default settings on your converter box so it doesn't turn itself off in a few hours.

Some DVD/VCRs have built-in digital (ATSC) tuners, some have only the old analog (NTSC) tuners, some no tuner at all. The "can't record digital to VHS tape" may be referring to trying to send the DVD/VCR's digital tuner signal to VHS tape, not the converter box's signal.