I have an outdated (but retro & cool-looking) Sony Watchman FD-500. It has a powerful radio & speaker as well as a 5" black and white tube television. Although digital broadcasts have pretty much ruined any chances of getting TV signals on the screen anymore, there is a 1/8" headphone jack-sized input on the rear for "EXT ANT". i found a coax-to-jack converter that allows me to plug in video inputs like a Nintendo once i tune it to Channel 3.
I was wondering if this same jack can also be used to feed in audio from an iPod or phone. Since it looks like a normal headphone jack I tried the obvious, a direct input, but something isn't going through. Here's a link to a page with photos: