Circuit diagram FM OSCILLATOR WITH BLY87
Circuit diagram FM OSCILLATOR WITH BLY87
Component list of the FM Oscillator with the BF900
Resistors:
R1 : 47k, 1/8 W R2 : 47k, 1/8 W R3 : 47k, 1/8 W R4 : 100E, 1/8 W R5 : 220k, 1/8 W R6 : 100k, 1/8 W R7 : 150E, 1/8 W R8 : 10k, lin. pot
Capacitors:
C1 : 100 nF Multilayer or ceramic C2 : 4.7 pF ceramic C3 : 100 nF ceramic (1 or 10 nF will do also) C4 : 40 pf trimmer C5 : 4.7 pF ceramic C6 : 10 pF ceramic C7 : 22 pF ceramic C8 : 1 nF ceramic C9 : 1 nF ceramic C10: 100 nF ceramic C11: 100 nF ceramic C12: 100 nF ceramic C13: 47 uF/25V C14: 1 nF ceramic
Inductors:
L1 : 4 wdg, dia 8 mm, 1 mm CuAg, space 1 mm;
Mounted 8 mm above PCB (Leads are 4 mm)
L2 : 6-hole ferroxcube wideband HF-choke (5 wdg)
L3 : 6-hole ferroxcube wideband HF-choke (5 wdg)
Others:
Q1 : BF900 D1 : BB405,BB102 or equal (most varicaps with C = 2-20 pF (approx) will do) U1 : uA78L08, uA7809, uA7810 or equal MC78LXX, UC78LXX
This package contains the schematic and PCB layout for the FM oscillator using the BF900 Dual Gate MOSFET, which is used between 90 and 110 MHz. and that he has a very low noise, and very stable. If you use the proper buffering, a PLL is not needed anymore .
For BF900 mounting holes (diameter 6 mm) should be created in which the casing can survive in. I myself have a problem with ‘the other side of the copper’, since the oscillator will not light (not really enough votes?? Just kidding). Was solved when I removed the copper BF900 (about 1 – 1.5 cm diameter).
