An On the Go (OTG) drive attaches to your recorder (or digital camera) via USB cable. This has two disadvantages. First, the recorder can't be used for recording while it's transferring files to the OTG drive. Second, the recorder's battery power is used while the transfer is taking place.
You can buy a drive with a flash card reader built in. This often is called a portable storage devices, or PSD. PSDs cost more than OTGs because they include a little LCD screen that tells you what the box is doing. OTGs just have a simple light that tells you that file copying is under way, but nothing more.
The OTG enclosure without a drive costs $50 to $75. The PSD enclosure without a drive costs around $150. In either case, add $75 to $100 for an 80 to 100GB hard disc.
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