The Stig - ver. 1.4: yes but its something to do with the data communication, because the Avant-VTR can't control it editor..
If had several changes to experiment with the HDR-1 combined with a MX7000 and Avant VTR, type 8100 and 8300).
It will work with a MX7000 or LX 6000, the channels will be dumped to the HDR-1 or 2.
It won't work with an Avant VTR, because there is an internal datalink, which you can't interupt/disconnect.
Even if you have an Avant, type 8300, with the latest software 4.2 combined with the Dolby Digital sound board.
If you set the Avant in the service menu (4) to "No VTape", there will be no tunerdump on the "Vtape" socket to the HDR-1.
It all has to do with the intenal connection between the Avant and the buid-in VTape.
The only way is to set it as a Vtape-2 on the AV socket. It will respond to Vtape2 instructions.
After putting all the sockets (Vtape, AV and Decoder) to "None", disconnect the Avant and HDR from the mains, and the reconnect to the mains there will be a tunerdump on the "AV"socket.
The main problem is, you need the tunerdump. If the HDR-1 hasn't done that, you're not able to make any timerrecordings. Even when you make them in the timerrecord menu from the HDR-1/2. The timerled will not show up.
If you have had the the tunerdump, it will light up.
If you have an Avant DVD, then there is a datalink on the Vtape socket and that's why it is supported.