connectorpower
Is this the correct convention for providing power to IEC cables/connectors in USA?
If your immediate reaction is "google it", I'm finding many diagrams online use somewhat ambiguous drawings instead of actual pictures of these things. It seems the "plug/pins/male" and "receptacle/sockets/female" words are often used incorrectly or it's unclear.
Most fans with a separate PWM-speed-control lead are designed to run at full speed if that lead is left floating. This is a safety measure so that, if the wire comes loose, the system won't overheat due to the fan stopping.
In general, all fans designed for use in PCs use the same wiring. Starting from the black wire, they are Ground/return, +power (almost always 12V but some non-PC fans use other voltages; check the label on the fan), tachometer (wire is grounded by the fan a certain number of times per revolution, usually 2 or 4) and PWM. The PWM wire is always on the end to allow a 4-wire fan to be plugged into a 3-pin connector for either no speed control or PWM control by interrupting the +power pin.
BTW, the link provided in the comment by M. Y., http://pcbheaven.com/wikipages/How_PC_Fans_Work/, with all of its edits, confirms all of this.
Assuming the ruler is showing millimeters, I'd say that the connector is of JST-XH-2.5 mm type with two pins. Sometimes, these connectors are sold and marked with 2.54 mm in their name, since that is a common spacing for inch-based measurements. Such connectors are commonly used for battery packs, so you might be able to find one, or a cable with one attached, in stores that sell equipment for radio-controlled planes/cars/boats etc.
My guess is that the radio was intended for use with a small loop antenna, such as one depicted in this photo from Wikipedia:
Most likely, two ends of such antenna would be connected to the appropriate female connector and then plugged into the radio.
Best Answer
The star indicates the N may be Hot with L2 while L is always Line.