- #1
Shelnutt2
- 57
- 0
So I'm trying to get my fm circuit to work. I've taken the design from the website below.
http://cappels.org/dproj/FMdist/fmdis.htmhttp://img217.imageshack.us/img217/6839/fmdis3un4.jpg
My current issue is that the circuit works, but only when hooked to a DC transformer. I get a signal of ~ 102 megahertz, but that's with a DC transformer hooked to it. Note the DC transformer is one we use at school, it has a varriable setting of 1-6 volts, and then 50/100/150/250/500 volts. I used the 1-6 connetions, and experimented between 1 and 1.5v, and same minimal difference.
Doesn't work:
AA battery, 1.3 volts, .0010 amps
9volt battery 8.8volts .03 amps
Works:
DC transformer 1-1.5v, .0015 ampsWHY? Why do I get no frequency with the battery but with a DC transformer I get a frequency?
Only thing I can remotely think of is maybe something having to do with the transformer converting the AC current to DC and causing a ~100 MHz frequncy? But I don't know as AC current is only 60 herts here in the USA...
Pics of circuit, and in these pictures the transistor is flipped. I made a mistake, and since then the transistor was repositioned and soldered intot he correct spot, so don't worry about that. (I had flipped the B and C of the transistor. I had E-C-B, its suppose to be E-B-C, and right this moment and during my test with the DC transformer and batteries it was E-B-C.)
http://img527.imageshack.us/img527/5135/1005418qb9.jpg
http://img523.imageshack.us/img523/2799/1005420wq0.jpg
http://img405.imageshack.us/img405/3905/1005424hg7.jpg
http://img523.imageshack.us/img523/716/1005426ca9.jpg
(^^ the gray stereo cable is for input, the to wires stuck to the ductape are unitl I go get a AA size battery holder, and the long black wire that's curled is the antenna)Thanks for the help guys. I've been looking for a Engineering forum for a while, this beats posting on ocforums.com (computer forums;)).
http://cappels.org/dproj/FMdist/fmdis.htmhttp://img217.imageshack.us/img217/6839/fmdis3un4.jpg
My current issue is that the circuit works, but only when hooked to a DC transformer. I get a signal of ~ 102 megahertz, but that's with a DC transformer hooked to it. Note the DC transformer is one we use at school, it has a varriable setting of 1-6 volts, and then 50/100/150/250/500 volts. I used the 1-6 connetions, and experimented between 1 and 1.5v, and same minimal difference.
Doesn't work:
AA battery, 1.3 volts, .0010 amps
9volt battery 8.8volts .03 amps
Works:
DC transformer 1-1.5v, .0015 ampsWHY? Why do I get no frequency with the battery but with a DC transformer I get a frequency?
Only thing I can remotely think of is maybe something having to do with the transformer converting the AC current to DC and causing a ~100 MHz frequncy? But I don't know as AC current is only 60 herts here in the USA...
Pics of circuit, and in these pictures the transistor is flipped. I made a mistake, and since then the transistor was repositioned and soldered intot he correct spot, so don't worry about that. (I had flipped the B and C of the transistor. I had E-C-B, its suppose to be E-B-C, and right this moment and during my test with the DC transformer and batteries it was E-B-C.)
http://img527.imageshack.us/img527/5135/1005418qb9.jpg
http://img523.imageshack.us/img523/2799/1005420wq0.jpg
http://img405.imageshack.us/img405/3905/1005424hg7.jpg
http://img523.imageshack.us/img523/716/1005426ca9.jpg
(^^ the gray stereo cable is for input, the to wires stuck to the ductape are unitl I go get a AA size battery holder, and the long black wire that's curled is the antenna)Thanks for the help guys. I've been looking for a Engineering forum for a while, this beats posting on ocforums.com (computer forums;)).
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