Michael (N4TMI) sent me an e-mail on January 21, 2008 with a pointer to the following information which he wrote.
The headphone jack in my Sony ICF-2010 recently disintegrated into a pile of plastic shards, and it's an unusual type; the replacement is no longer available, even from Sony. So I worked out how to use a more widely available jack. Here's what's involved.
You will find that you can mount this in the hole left by the original headphone jack; you'll attach it to the enclosure rather than the circuit board, of course, and orient it so its connection terminals are down, toward the front of the radio and away from the circuit board.
Wire it as follows:
Headphone jack wiring
That is, at the speaker, find the white and black wires and interrupt the white one, then proceed as shown in the diagram. The 15-ohm resistor is a trick of mine: it lets you connect stereo headphones and hear sound in both ears, but at the same time, you can use mono headphones without shorting out the audio signal. Admittedly, the volume in the two ears is not equal; the right ear gets more sound, but the difference is not large.
One more note: If your Sony ICF-2010 goes dead while you're working on it and won't turn on, but its front panel clock is still running, you may have simply hung its computer. The cure is to remove all the batteries and let the computer reset. If you've installed a memory backup capacitor (as I have), you must discharge it.