The Radio Room

Remember when ships had real radio operators? If you do you'll know that the ops had to maintain "silent periods" when they wouldn't transmit, instead listening for distress calls on 500kHz and 2182kHz.

As a reminder, a radio room clock would have the 500kHz silence periods marked by shading the sectors between h+15 to h+18 and h+45 to h+48 in RED. Similar sectors between h+00 to H+03 and h+30 to h+33 were marked in GREEN which is the corresponding silence period for 2182 kHz.

Anyone breaking the rules would soon hear "QRT SP" in Morse Code, meaning "STOP SENDING - SILENT PERIOD!"

These products, including a reproduction radio room clock, let you relive those bygone, halcyon days when "sparks" ruled the maritime airwaves.

Note: The organic T shirt and one of the clocks has the red 500kHz CW sectors only at the request of the US MRHS.