The 1920s Radio Network sends 25, 35, and 25/35 Hz tones at the top and bottom of hour so affiliate stations can control their automation systems for local avalis (breaks.) Your station has two local avails, one 20 seconds before the hour, and the other at the bottom of hour. The top of hour break is fixed hard start at 20 seconds before the hour. The top of hour avail has two subaudible tones at 25 hz before and 35 hz after the break. The bottom of hour uses a 25/35 hz mix tone to start, and a 35 hz tone at the end. We use the 25 as top of hour trigger, 23/35 as bottom of hour trigger, and the 35 is the network rejoin. Additionally we use three 1 khz tone bursts at the top of hour followed by a longer 1 khz tone. The bottom of hour break has just one tone burst to differentiate from the top of hour. Please see the break cue structures below for exact details

Attention Affiliate Stations:

Note: The top of hour avail appears on all hours, but the bottom of hour is not used during syndicated program hours, or Old Time Radio hours, due to the nature of the floating breaks

CircuitWerkes sells a small subaudible decoder that will decode our tones