Welcome to Satellite Guys! The Duo can receive FTA DVBS MPEG2. Most channels on 97w are still transmitted in this format. Even though many threads are several years old, the aiming and scanning process remains the same.
The dish aiming is highly critical along with the correct LNBF skew (rotation) and the receiver must be set to an active transponder for the satellite that you are trying to find. It is very important to mount the dish on a solid pole that is plumb and level. This will simplify the aiming procedure!
Use a dish aiming program like Dishpointer to find the compass reading, elevation and LNBF skew for 97w - Galaxy 19. Aim the dish in this direction and set the LNBF skew and elevation angle. This is assuming that the new LNBF has been mounted so the feedhorn is in the exact position (height, distance from the reflector and angle) matching the removed Directv feedhorn. Remember that the Slimline dish is an offset type design and is actually looking at a point in the sky that is approximately 26 degrees higher than the face of the dish is aimed. Make sure there is nothing blocking this (roof overhang, branches, etc.).
Look at Sathint.com and find an active transponder for 97w -G19 KU band. I suggest using TP frequency 12152 Horizontal, SR 20000. On the DUO Install menu, select the KU band satellite located at 97w (the name is not important as it likely has changed). Set the transponder to the above suggestion, select LNB type to 10750, LNB Power to ON.
With the TV screen next to the dish, SLOWLY pan the dish 20 degrees on either side of the compass reading for 97w satellite while watching the Signal Quality Meter. Once the signal is found, the Signal Quality reading will increase. The meter reading may momentarily jump as the signal is being located, but if it doesn't stabilize, it is likely a false reading.
If no Signal Quality reading is noted, increase or decrease the dish elevation setting in one degree increments and SLOWLY sweep the section of sky again. Repeat until the satellite Signal Quality reading is locked and optimized.
Once the satellite is found, perform a Blind Scan for ALL channel types. You should scan in over 200 free channels on this satellite.