Start with the signal path
For a field setup, the fastest chain is a handheld or scanner speaker into a phone microphone. It works surprisingly often for strong signals, especially when the pass is overhead and the room is quiet. Keep the phone still, turn off loud notifications, and set the radio volume below the point where the decoder input clips.
A wired path is more repeatable. A small isolation interface or attenuated audio lead removes room noise and keeps the receive level steady. If the decoded picture leans, curls, or tears line by line, save the recording before changing settings; the same audio can usually be corrected later.
Three setups worth keeping ready
Walk-up receive
Handheld radio, stock antenna or small whip, phone microphone, live decoder, and a note of UTC time plus frequency.
Garden pass
Handheld or scanner, small directional antenna or outdoor quarter-wave, wired audio when available, and a pass prediction open before AOS.
Desk replay
SDR or receiver audio recorded to WAV, then decoded more than once with slant and frequency correction after the pass.
What to log
Log the source, UTC window, frequency, mode if known, receiver, antenna, audio path, sample rate, and whether the decoder selected the mode automatically. That little log makes a bad image useful because it gives you something to adjust next time.