Has anyone measured the harmonic content of the Juma 136? It seems that the 3rd harmonic is pretty strong, I am a bit worried about meeting the FCC specs.
If you are worried about suppressing a third harmonic further, add another five pole low pass filter between the transmitter and the antenna. Two toroids and three capacitors, identical to what is already in the rig. That may also help reduce any signals from nearby broadcast transmitters getting into the receive converter.