Hi,
I'm new here and I hope I'm in the right forum.
In the past two weeks I've built some FM transmitter circuits. My aim is to create very simple circuits.
The schematics are shown in the attachment.
The coil in the first schematic ist made of jumper wire. Its diameter is about 5 mm, the length is about 7 mm and it has got 4 turns. In the second schematic aren't actually two coils, it's one coil with a tap (I didn't know how to draw this in my schematic porgram). Diameter 5 mm, length 7 mm and 4 turns. The tap is after the third turn.
The mikrophone in the second schematic is a carbon microphone. In the first schematic the signal of an MP3-Player is fed into the input.
Unfortunately there are a few problems:
1.) The first schematic works, but if I go around in my room it has affect on the signal strength. Sometimes there's no signal at all in the radio.
2.) Where in this circuit it is possible to connect an antenna?
3.) The second circuit doesn't work. A friend has built this circuit in the past, and it worked. Does anybody see a problem?
Thank you in anticipation!
Best regards
BC548C
P.S: I'm from Germany and I'm still learning English at my school, so please do not stone me to death if some sentences or words aren't correct ;-)
I'm new here and I hope I'm in the right forum.
In the past two weeks I've built some FM transmitter circuits. My aim is to create very simple circuits.
The schematics are shown in the attachment.
The coil in the first schematic ist made of jumper wire. Its diameter is about 5 mm, the length is about 7 mm and it has got 4 turns. In the second schematic aren't actually two coils, it's one coil with a tap (I didn't know how to draw this in my schematic porgram). Diameter 5 mm, length 7 mm and 4 turns. The tap is after the third turn.
The mikrophone in the second schematic is a carbon microphone. In the first schematic the signal of an MP3-Player is fed into the input.
Unfortunately there are a few problems:
1.) The first schematic works, but if I go around in my room it has affect on the signal strength. Sometimes there's no signal at all in the radio.
2.) Where in this circuit it is possible to connect an antenna?
3.) The second circuit doesn't work. A friend has built this circuit in the past, and it worked. Does anybody see a problem?
Thank you in anticipation!
Best regards
BC548C
P.S: I'm from Germany and I'm still learning English at my school, so please do not stone me to death if some sentences or words aren't correct ;-)