167
2.66 Simple AM-Radio
Circuit 141:
Simple AM-Radio
Setup information
Install the three transistors, the four resistors, the three ceramic capacitors, the fixed value inductor and the
two electrolytic capacitors as shown in
Fig. 2.141.
Then insert the 20 jumper wires. Last but not least, con-
nect the Piezo element. Check the placement on the board again and only then connect the battery. You can
significantly increase the sensitivity of the Piezo element by using a sound plate or even a sound box. Read
more about it in Chap. 1.2.3
Components required:
2 x 2N3904 transistors,
1 x 2N3906 transistor,
1 x 1 k
Ω
resistor,
1 x 2.2 k
Ω
resistor,
1 x 470 k
Ω
resistor,
1 x 1 M
Ω
resistor,
1 x 220 μH fixed induct-
ance, 2 x 100 nF ceramic
capacitors, 1 x ceramic
capacitor (see Experiment
for value), 1 x 1 μF electro-
lytic capacitor,
1 x 10 μF electrolytic capaci-
tor, 1 x Piezo element,
1 x breadboard, 1 x 9V bat-
tery with clip connector
Fig. 2.141:
Simple AM-Radio
Experiment
This circuit is a simple yet responsive and selective AM receiver for MW. If you have, use a small variable
capacitor (about 200 pF) from your crafting box for C1. If you don’t have one, experiment with the ceramic
capacitors of the experiment box (10 pF, 100 pF, 220 pF). One of the many possible different parallel/series
combinations will almost certainly establish a good radio reception. The best reception conditions are at
night when you can also receive stations from southern Europe. Germany and Austria have no AM broad-
casting station any more.
The circuit diagram for this experiment is shown in Chap. 3, Fig. 3.141.
Содержание ELECTRONICS EXPERIMENTS BOX
Страница 4: ......
Страница 251: ...253 Fig 3 27 Circuit 27 4 seconds switch off delay Fig 3 28 Circuit 28 20 seconds switch off delay...
Страница 258: ...260 Fig 3 42 Circuit 42 Active 8 5V battery monitor Fig 3 43 Circuit 43 Active 7 8V battery monitor...
Страница 260: ...262 Fig 3 46 Circuit 46 Meters for 1 5 V Zener diodes and higher Fig 3 47 Circuit 47 Discreet 2 2V Zener diode...
Страница 261: ...263 Fig 3 48 Circuit 48 Discreet 2 9V Zener diode Fig 3 49 Circuit 49 Discreet 3 7V Zener diode...
Страница 265: ...267 Fig 3 56 Cir cuit 56 Audio limiter Fig 3 57 Circuit 57 Amplifier for a storm detector...
Страница 269: ...271 Fig 3 64 Circuit 64 Stabilizer for 1 9 V Fig 3 65 Circuit 65 Stabilizer for 2 5 V...
Страница 275: ...277 Fig 3 80 Circuit 80 Quiztimer 30 seconds Fig 3 81 Circuit 81 Handy diode tester...
Страница 290: ...292 Fig 3 118 Circuit 118 HF watch dog with LED indicator Fig 3 119 Circuit 119 HF watchdog with moving coil instrument...
Страница 295: ...297 Fig 3 130 Circuit 130 4 seconds switch on delay Fig 3 131 Circuit 131 15 seconds switch off delay...
Страница 298: ...300 Fig 3 136 Circuit 136 NAND gate with moving coil instrument Fig 3 137 Circuit 137 Input level Mixing console...
Страница 300: ...302 Fig 3 140 Circuit 140 Electrometer with moving coil instrument Fig 3 141 Circuit 141 Simple AM Radio...
Страница 315: ...317 Fig 3 179 Circuit 179 HF generator 150 kHz Fig 3 180 Circuit 180 HF generator 420 kHz...
Страница 324: ...326 Fig 3 202 Circuit 202 3 seconds switch on delay Fig 3 203 Circuit 203 7 seconds switch on delay...
Страница 325: ...327 Fig 3 204 Circuit 204 Piercing siren sound with Piezo element Fig 3 205 Circuit 205 Discrete Operational ampli fier...
Страница 328: ...330 Fig 3 210 Circuit 210 Discreet 5 2V Zener diode Fig 3 211 Circuit 211 Discreet 7 4V Zener diode...
