I do love the sound of a PA15/20.The sirens I like to hear are long gone:
Early Federal PA15A/PA20A: B, C, and D series.
Early Smith & Wesson Magnum series: III, IV, V, VI.
Signal Stat 'Stat VI' (NYPD)
All have slow rising low pitched tones.
If you do, keep in mind that there were three major variations of the 15 and 20:I do love the sound of a PA15/20.
I bought a HHS3200, thought about running a PA series siren as well.