Vintage center pull brakes have no barrel adjusters.

So, it depends entirely on your setup. Most of the vintage brake levers with cables coming out of the top of the levers also had barrel adjusters where the cables exited. Aero brakes lost that adjustment point.

You also have to have a cable stop either somewhere around the seat on the rear, or at the stem or headset on the front, and sometimes that stop will have an adjster.

Too adjust the barrel adjusters, I would frequently pull on the brake lever, then release the brake lever and pull up on the cable housing to relieve tension while I did the adjustment.