Portable FM Transmitter From China
This Review is for the Portable FM Transmitter from China. In this case, the 7W 7C FM Transmitter. However, it would most certainly apply to ALL the Iterations of anything based on this design. For the most part, this works out of box in the "Low" Setting (1W). However, on the "High" Setting (7W), the RF can invade the Auxiliary Input for Audio and cause, at the VERY least, cause an undesired "Hum" in the Audio Source. In the WORST Scenario, though, this will wipe out your Audio Entirely, as the RF causes a Temporary Short in theTransmitter Stage. Neither of which is desirable. To combat this, you must: (a) Just Run an External Ground Plane Antenna. Get rid of the Telescoping Antenna which was included with the Initial Purchase. Doing so does not allow the RF down the Input Cable and requires no further action as a more efficient Antenna is used. (b) You MUST purchase an "RF Choke" and install it over the Auxiliary Audio Input Cable. It does no good to install the Choke at the Amplifier END - it MUST be installed at the OUTPUT end of the SOURCE you're trying to use. In my case, I purchased a "Two-Pack" of the RF Chokes. Using both in Tandem solved my Problem. Long story short: If you're having difficulties running this Device in "High" Mode, and are experiencing a loud HUM caused by RF Feedback, this is what you need to do to solve the problem. Hopefully this helps future Buyers and Sellers Alike!!!! Note that all Scenario's are not 100% alike, and you MIGHT NOT have this problem that I did. However, if you do, now you know what to do to solve it! :-)
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