TRANSMITTER CIRCUITS
​
0.5 W AM MEDIUM WAVE TRANSMITTER
Frequency: 0.8 - 1.6 MHz
Power supply: 14 V d.c. (150 mA)
Input sensitivity: 0.5 V
Output impedance: 50 Ohm
X1: 4 x frequency
H: Heat sink
Ferrite rod Inductor: 50 turns (0.8 – 1.4 MHz) 40 turns (1.0 – 1.6 MHz) 33 s.w.g.
​
​
2.5 W AM MEDIUM WAVE TRANSMITTER
Frequency: 0.8 - 1.6 MHz
Power supply: 14 V d.c. (650 mA)
Input sensitivity: 0.5 V
Output impedance: 50 Ohm
X1: 4 x frequency
H: Heat sink
Ferrite rod inductor: 50 turns (0.8 – 1.4 MHz) 40 turns (1.0 – 1.6 MHz) 27 s.w.g. 10 & 3 turns 22 s.w.g.
Replace: VN66AF for IRF510
​
2.5 W 80 / 40 m TRANSMITTER
​
Power supply: 14 V d.c. (600 mA)
Input sensitivity: 0.5 V
Output impedance: 50 Ohm
X1: Frequency in the 80 or 40 m band
H: Heat sink
Ferrite rod inductor: Use 22 s.w.g.
Replace: VN88AF for IRF510
​
For the 40 m band use a heat sink for the BFY51
Replace: 470 for 270, 47 k’ for 22 k., 100 pF for 47 pF, 7 turns for 3 and 12 turns for 7
​
​
0.7 W FM TRANSMITTER
Frequency: 88 to 108 MHz
Power supply: 14 V d.c. (240 mA)
Input sensitivity: 0.7 V
Output impedance: 50 Ohm
H: Heat sink
Inductors: 5 mm dia. 22 s.w.g
Replace: VN66AF for IRF510
​
1 W FM TRANMITTER
Frequency: 88 to 108 MHz
Power supply; 14 V d.c. (330 mA)
Input sensitivity: 0.6 V
Output impedance: 50 Ohm
H: heat sink
Inductors: 5 mm dia. 22 s.w.g