bought an NOS 6V6GT tube which i recieved today. it's missing a pin which i thought obviously means it's faulty. but having searched on the net i'm finding that sometimes pin1 is ommited. is this true? am i right in saying the round bump at 12o'clock is the key, so the missing pin is pin6 yes? which just means the tube is no good? just want to check before i return it.