If you want to run your transmitter at full legal power, do the following:
1) Take apart the unit by removing the eight screws on the back and front of it.
2) Locate the power transistor (Q7) and remove it. My unit had an NEC 2SC3355 in it. I was able to locate mine by getting a number off it and using a rudimentary schematic I found on the net. This is what drives up the power on the claimed Rohm BH1415F FM IC. Notice the orientation of the transistor so you can locate the base from the emitter and collector.
3) Put a jumper from where the base of the transistor was connected to a point on the antenna trace. I soldered to what is marked as C45 on the schematic. From what I could tell that coupled the signal to a matching/filter network.
4) Shorten the supplied rubber ducky antenna. I unscrewed the external plastic cover off mine, then started to cut off short pieces of it until I got a reading on my spectrum analyzer under 48dbuV at 3m. I basically cut the antenna in half. I shortened the antenna because I still got a reading of 62.32 dbuV (1306 uV) at 3 meters which is over the limit of 47.988 dbuV (250uV) at 3 meters.
My transmitter was laying in a pile of junk collecting dust. From what I remember, it sounded muffled. I've read that the preemphasis isn't set correctly. Still need to hook up mine and see how it sounds.
Rock On
How did I do?