Problem - Repair - No Output
This is (Was) a very clean, inexpensive Part 15 transmitter. The range, for it's power, is amazingly good. Why (Was)? FCC put Ramsey out of business, allowing Chinese imports with much higher (Illegal) power. Keep your USA Ramsey alive. If, (When) it fails, fix it. So far, the main complaint about the Ramsey, is the PA fails. See below to fix it and prevent future failures.
If your Ramsey FM25B transmitter has stopped wording, (No Output), the PA has failed. What caused this? Most likely, static. You were charged with static, touched a metal part of the transmitter (Antenna) and it took out the GAL 5 chip. Although it appears the GAL5 is discontinued, the replacement is a GALI5.
After receiving a pack of new GALI5 chips from Ebay, one was installed. Immediately, RF returned, but a new problem started; the PLL would not lock and hold. Solution: Replace it again with another chip. Chinese chips are hit and miss. Some are good, while others are not. Installing the second chip resolved all the problems and the FM25B works like new.
To prevent this from happening again, install a 2.2 µH coil across the RF output.
|
