Broadcast FM Whistling

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Broadcast FM Whistling
BroadcastFM Whistling 2.JPG
Frequencies 102 MHz
Frequency Range 102 MHz - 102 MHz
Mode DSB
Short Description

I was scanning FM radios when suddenly I found this.

Possible solution: Hobbyist single-transistor tracking transmitter.
I/Q Raw Recording
Audio Sample

Additional Images[edit]

BroadcastFM Whistling 1.JPG BroadcastFM Whistling 3.JPG

Solution: Probably single-transistor SAW oscillated TXTransmit, probably hobbyist. Data input and/or Vcc of TXTransmit seems to be discharging a capacitor which is periodically fed a charge pulse; doing that to a single transistor TXTransmit results in exactly this, a signal that gradually drifts it's frequency while lowering it's amplitude. This can be used as a tracking transmitter, compatible with USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables) mode; it could be for a lost RC plane finder for example. The lower/higher pitch tone audible at the fadeout-spot, and the louder the general volume, the closer it is.