FM Transmitter Problems

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can i ask a question? what would happen in this situation if you screwed the antenna wire to the metal body? would the metal body then become an antenna? or would it not work at all?
 


I'd like to go with modifying my existing unit. I might try using AudioGuru's amp from another thread. Do I run the risk of burning out my transmitter by connecting the antenna to this circuit?
 

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My RF amplifier has a 33pF input capacitor which protects the transmitter from damage. This one uses a 4.5V battery for a fairly high power output. Another one uses a 1.5V battery for hardly any output power (like the BA1404 IC). My FM transmitter is designed for a 9V battery for plenty of output powetr.
 
Could I just strip the insulation off the end of the 55" antenna coming out my transmitter and connect it to your RF amp? Or would I have better results (less interference I would think) if I cut the existing antenna off and connected it directly to the transmitter?
 
Connect the output of your transmitter directly to the input of the RF amplifier circuit with the shortest wires (output and ground) you can.
 
Horray!
The feds in Canada changed the law so the RF cops can't shoot you and chop off your head anymore.

Now you get to tell a judge why the interference from your FM transmitter caused an airplane to crash and caused TV interference to thousands of couch potatoes. Maybe the judge will chop off your head.
 
I think this transmitter is very likely be made out of a BH1417, and since the RF output of it is weak, a single stage amp made of a transistor might be already added, then about 10-20mW can be produced. to reduce the size, the ant is just the audio line (an inductor isolates the audio and RF signal). so, if you wanna improve the range, it is better to isolate the ant from the audio line, let your metal house be the ground, and set up an ant above the house and be sure it is isolated with the metal house.
 
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