300W FM Broadcast Reference Design using the BLF278

Enigma Component Shop Ltd Verified independent store

→

NOT FOR SALE IN THE UK The FM300v2 is a broadband 300W amplifier for the FM broadcast band. We've recently managed to source a quantity of used BLF278 transistors at a great price, so have provided a reference design so that a low-cost, high performance amplifier can be constructed from the plans provided here. This design is available as a paid download. Files will be available once a purchase is made. Features Broadband 300W FM broadcast amplifier operating from 87.5-108MHz Only 0.5-1W input drive required Microcontroller controlled on-board 2-stage thermal and SWR protection Fault output to power down exciter during a fault High efficiency - cool running High reliability - designed for years of continuous use at 100% duty Low harmonic content, suitable for direct connection to an antenna PCB Gerber files and full construction details with parts list provided as a digital download Specifications Power gain 25dB typical Gain flatness +/- 1.3dB Output power 320W typical Efficiency 68-78% (73% typical) Output power 270-345W (320W typical) DC Current consumption (main supply) 48V, 8.5-10.5A (9.5A typical) DC Current consumption (pre-drive) 12-15V, 1A Input power 0.5-1W Harmonic output -74dBc typical We sell many of the parts to make this amplifier, and full details are provided on the parts list. A limited number of PCBs are available here. A programmed microcontroller for this design is available here. Show more