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How can I wire this up?

I found this today down at the beach, an old broken fm transmitter, and it looks like it had been down there a while. However the transmitter unit itself for some reason is detachable, and it says 5v on the back. Does anyone think it would be possible to wire this up to maybe usb 5v and somehow wire an antenna up to it? That would be so sweet if I could use an old P1 to broadcast a radio station :D

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NachoMahma8 years ago
. Lost my first reply when the system went down around midnight (Robot time). Here are the high points. . While the pics don't look too bad, water damage is a definite possibility - don't get your hopes up. With the sand in there, I'm guessing the odds of a favorable outcome are real close to zero. Worth a try, but don't get too excited. ;) . Find the manual online. Should have some specs and you're probably going to need it to figure out the 3-button interface if the thing does still work. . It broadcasts on the standard broadcast FM band (88-108MHz), so if you put a booster on it, don't be surprised if you get a visit from the Canadian equiv of the FCC. ;) . No idea what the 5-pin connector is. I'll guess it's for diagnostics. Is that CN2 printed next to it? Since one of the PCB traces goes to SW2, it could be for remote control. . Judging by the size of the components in pic 12, I'm guessing the two square things are not caps.
Punkguyta (author)  NachoMahma8 years ago
I just got it to work! I found the perfect thing, A 5v wallwart, and at 0.5amp, the leds a pretty bright. The power connector is a bit loose or something because if I swivel the power jack, it shuts off. I plugged my compter's output into it, but alas, nothing came out of my stereo when I tuned the channel to 96.1, which is the station I had it tuned to on the transmitter. It might be that I don't have an antenna hooked up to my stereo, but it should have came in a little fuzzy at least, but all I heard was static even when I turned it up. How do you think you would attach an antenna to the transmitter?
DSCF0644.JPGDSCF0639.JPGDSCF0642.JPGDSCF0643.JPG
. Woot!
Punkguyta (author)  NachoMahma8 years ago
Just woot? How do I get some actual audio output of this sucker?
Try playing something right next to your stereo. If that doesn't work, look for a wire, or a trace on the PCB board that's particularly long and winding, and leads to no where... this would be the antenna. If there isn't one, then that's your problem. Look for a spot wear a wire might have broken off, or the solder broke, etcetera.
Padlock Padlock8 years ago
If you still don't get anything, try soldering another foot of wire to the antenna, and then try hooking it up to an oscilloscope. It could just be that the transmitter chip is busted. (Besides... you can buy these things for $5 - $10 at Target)
those black components are caps. the numbers are uF and V and the white line is +
Punkguyta (author)  NachoMahma8 years ago
That's always a real bummer even when you're in the middle of posting an instructable and your browser crashes, I know how ya feel. Fortunately, they've invented a new save feature into the editor, pretty nifty if I say.

You're right, it probably is a gonner, but the fm transmitter circuits themselves seem to have been better sealed. None of the componants look corroded in any way, and the lcd might even still work. I suppose I need to find a 5 volt wall brick and the right end, or solder power wires onto the pcb?

>Find the manual online. Should have some specs and you're probably going to need it to figure out the 3-button interface if the thing does still work.

. That might be an idea, the Griffin Roadtrip is discontinued, but thankfully there's a manual.

However, it doesn't really help as far as schematics go when finding points to solder an antenna to.

> It broadcasts on the standard broadcast FM band (88-108MHz), so if you put a booster on it, don't be surprised if you get a visit from the Canadian equiv of the FCC. ;)

.How the hell would they know Where to find me??!

>No idea what the 5-pin connector is. I'll guess it's for diagnostics. Is that CN2 printed next to it? Since one of the PCB traces goes to SW2, it could be for remote control.

.I just looked at that. Pin 1 and 2 go to buttons 1 and 2. Pin 3 appears to be a power trace, as it connects at the underside of the board, I made a new note in the underside picture of the board to show you. Pin 4 traces to a smd resistor, and then to the 2nd? leg of the chip on the bottom right corner of the pcb, as I'll mark above in picture 9. Look in picture 12 also for pin 5.

Interesting connections.

I'm gonna try applying 5v to it and see what happens
Punkguyta (author)  Punkguyta8 years ago
Oh, upon inspecting the pdf of the manual, apparently this unit can be used as a desktop unit with a usb-audio combination cable (usb apparently just provides power). So I was right, I can wire it to a usb jack :P. I also have a handy usb hub that has 2.0 amps of power so that should be enough.
lemonie8 years ago
You think this might have been in working order when it was discarded? Good luck! L
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