Re: small FM transmitter for mobile pirate transmitting

There are some transmitters where you can select 50 or 75 for different countries.

I remember Ramsey's FM-10 using 50, and it had a better reason, keeping the treble reduced a bit, so it wouldn't interfere as much with the 19 khz pilot and subcarrier frequencies.

The newer transmitter chips have filtering, but there's still the pre-emphasis to deal with, the highs are pumped up so much that peaks can overmodulate, even at low sounding volume levels on a receiver. For that I'd use a software pre-emphasis limiter such as found in Sonos LImit, and other software processors that will take the edge off of those peaks, and that will improve your sound.