Three and many other questions can be answered in the LD5 manual find on our web page under the “manuals tab.
Yes, filtering is built in. There are 4 filters for each mode. Three are preset but adjustable in the service menu. The fourth is useradjustable on the fly.
Yes, digital operation is a available without the use of a separate sound card.
FLdigi,digipan, micwindoes, HRD etc will all work with t the LD5. Instructions are also included in the manual for a very simple interface cable.
No, there is no internal battery. A separate power source is required.