There's been a lot of discussion on the post I wrote a few years ago about the Scientific Atlanta Explorer 8300HD Hi-Def DVR (March 5, 2005), mostly about how to expand its rather limited recording capacity.
The good news is that doing so is both easy and cheap! All you need is an external hard drive with an eSATA connection and eSATA cable.
For this project, I used an Acomdata PureDrive PDHD750USE-72 750GB 7200 RPM 16MB Cache USB 2.0 / eSATA External Hard Drive (~$100) and a 2m eSATA cable ($25 at my local computer supply store). For the uninitiated, eSATA stands for "External Serial ATA" and is a new, fast standard for connecting external mass storage devices to computers and similar components.
To install the drive, I followed these simple directions:
1. Turn off the DVR (hit the power button on the front of the unit)
2. Connect the eSATA cable to the drive and to the DVR (the eSATA connection is on the back)
3. Turn on the drive (if it has a power switch; otherwise just plug it in)
4. Turn on the DVR. At this point, you will be prompted by the DVR on your TV that a new drive has been attached and asked if you want to format the drive. You'll indicate "Yes" by hitting the yellow A (triangular) button on the DVR remote. A message will come up stating that the drive is being formatted.
5. After a few minutes, the message will disappear and you're all set.
Before attaching the 750GB drive I used, my DVR was 56% full. After attaching it, the DVR was 9% full. Now that's change I can believe in!
If you're looking for drives to use in this manner, try to get one that's fanless (like the Acomdata unit above); otherwise, the fan noise might degrade your TV experience.