lol!
Sorry, couldn't help it. Diodes are pretty small, and even if you were to use a macro lens to get a super close-up pic it wouldn't help much at all. There usually is print on them, but takes a strong eye and a magnifying glass to read them. If you know the location it came from, look it up on the schematic and there will be a part number that identifies it. The most common diode in most radios is the 1N4148, a common signal/switching diode used in many places. But there are other kinds of diodes and they are also used in the radio for different jobs. Biasing, clarifying, regulation, protection, and so on.