I second the Md suggestion.

Further suggestions:

Make sure you buy a MD recorder which has a plug for a microphone. In the old days all of them had such a plug. Now such plugs are increasing rare.

If you are used to working with portable analog tape recorders, be warned that MD recorders as a rule do NOT come with a built in mic. It must be purchased separately. The Sony Sony MZ-B10 is the only MD recorder I am aware of with a built in mic.

When you actually start recording don't repeat the mistake all us amateurs made in the old days. Start the recorder and KEEP IT GOING. Don't worry about dead air and extraneous material. Don't bother to turn the recorder off and on to catch just the good bits. Just keep feeding the recorder discs until your source quits. The editing can be done back home at the PC. You will never regret filling a disc with useless noise. You will regret to your dying day missing the great story that preceded the song you did record.

Always carry lots of discs and lots of batteries. Carry way more than you think you'll use.

Keep a log if feasible. Who? Where? When? No matter how good you think your memory is, it isn't good enough.

Can't keep a log? Be scrupulous about labeling the discs.
Even if you keep a log, be scrupulous about labeling the discs.

Even if you are scrupulous about labeling your discs and keep a detailed log, begin each disc with a statement of who, when, where.

Record everything. What you think you are interested in today, what you will be interested in a year from now, and what you will wish you had recorded 5 years from now are very different things.