SL40 Directional broadcasting?

I have an SL40 with a Rami bent antenna (the metal kind with a bend in the middle of it) mounted on the bell and it seems to transmit really well behind and to the side of the aircraft, but transmitting forward the range seems to be cut in half.

I can easily talk to someone 15 miles behind me, but I have a hard time talking to someone beyond 8 miles in front of me. This creates issues when I'm trying to fly towards an airport and call the tower.

I can receive transmissions really well, I don't have any issues receiving when someone is calling me. Any help is appreciated.

Not trying to sound like a broken record (or corrupt MP3 file) but if you can receive just fine but have transmit problems, check your coax cable and antenna ground for good connection(s). Corrosion, especially where the antenna grounds to the airframe, can create weird problems that sometimes affects transmit more than receive.

While in theory receive abilty should be the same as transmit for an antenna, in practice it?s hard to tell. Modern receivers are extremely sensitive, and their AGC circuits tend to mask antenna directionality, e.g., the signals from behind may be 100 times stronger than from in front, and they?ll both sound okay. You need a real signal strength meter to know.
I have a very similar set up: bent whip on the belly, SL-30. One time (and only once) I was pointed straight at the tower, descending nose down. Tower responded to my call with ?weak and unreadable?. Other nearby aircraft called the tower, said they heard me fine. I switched to my #2 com, on an Archer wingtip antenna (not as good as the external whip, usually; but not as bad as some believe). Tower said 5 by 5. A few minutes later, after a 45 deg turn, I went back to #1 and tower said loud and clear. I think it all depends on where your antenna is with respect to the landing gear legs, maybe some other wires in the engine compartment, etc.It?s a bit of a black art, mostly trial and error. For sure, check coax connections. Beyond that, you may have to try other locations.