FM Transmitter from 1999

thingiverse

This design originated back in October 1999, and it strictly complied with FCC part 15 regulations. The MC2833 is still readily available on online marketplaces like eBay, while the coils should not be hard to locate. The datasheet has all necessary information, including component numbers, required for assembling a small, single-channel FM transmitter that operates within one of several designated bands. For reference purposes, I'm including the schematic for this design (the product was initially engineered to operate on the 72MHz ISM frequency band). Initially designed with an early version of Protel (Advanced Schematic 1.x and Advanced PCB 2.8), it was manufactured in New Zealand by myself and subsequently exported to the USA under the "Califone" brand as an FM cordless Headset (a matching receiver existed for this model). In addition, I'm currently searching through old design files to retrieve different audio stages designed specifically for various versions of this product. This release makes for a relatively effective FM transmitter during radio-based "Fox Hunts," and a significant portion of surplus stock was eventually sold to radio enthusiasts who utilized the device for that purpose.