576: Who invented the cubical quad antenna in the late 1930's?

577: SWL (shortwave listening) QSL cards cannot be sent though the ARRL Outgoing QSL Service.  

578: The GAP antenna company began in which year?

579: What is the maximum power allowed for a standard AM broadcast station in the USA?

580: For what purpose could a ham use a 1R5 in homebrew equipment?

581: When attempting to qualify for an ARRL Code Proficiency (CP) award, it is OK to tape record the broadcast, and attempt to copy it later.

582: What is the maximum WPM (words per minute) CP (Code Proficiency) award ARRL offers on a W1AW qualifying run?

583: What is the lowest WPM (words per minute) CP (Code Proficiency) award ARRL offers on a W1AW qualifying run?

584: A typewriter cannot be used to copy code during a W1AW code proficiency qualifying run, because it is a mechanical device.

585: How many different code speeds are sent in a typical W1AW code proficiency qualifying run?

586: A Code Proficiency award from W1AW/ARRL at 20 WPM will be accepted as sufficient evidence of meeting the new FCC code requirement of 5 WPM for all licenses.

587: Under the current call sign assignment system (in the USA), how many potential USA amateur call signs are tied for being the longest to send on CW?

588: All of the eighth call area is in the Eastern Time Zone

589: Who received the first U.S. government Ham Radio license?  

590: The Mississippi River originates in what state/call district?

591: How many FCC call districts, and how many total states, border the Mississippi River?

592: The Mississippi River begins and ends in what FCC call districts?

593: In what call district do the names of 3 states end with "ota"?

594: Alexander Graham Bell once taught as a Professor at which Boston, Massachusetts University?

595: All solar (sun) activity results in improved radio communications.

596: Arthur Godfrey's ham radio call sign was:    

597: The first 6-meter DXCC awards were completed in what peak sunspot cycle year?

598: You notice while surfing the TV channels that there is a strong signal from a station on channel 8 nearly 300 miles away. Which amateur band should you try for an unusually distant QSO?  

599: It is not possible to work both "short path" and "long path" radio communications to one other location at the same time.

600: Hiram Percy Maxim was president of ARRL from 1914 to what year?