a28
bob: what was the frequency of the captain crunch whistle used to make free phone calls?  l337 h4x0/2 : i believe the frequency was a28 hz bob
a28 is 2600 in hexadecimal
"bob: what was the frequency of the captain crunch whistle used to make free phone calls?  l337 h4x0/2 : i believe the frequency was a28 hz bob" What is the definition of "a28"?