One very practical way to provide gate drive to the final RF amplifier is to use one of the several RF driver ICs available for the purpose. Some of these driver ICs will operate on 30 mHz or higher. If you chose the correct driver IC, it is possible to provide almost square wave drive to the gates of the RF amplifier MOSFETs, which can result in more efficiency and will significantly reduce the possibly of parasitic oscillations in the RF amplifier. Since the driver is not tuned, it is possible to operate the driver on multiple bands, making multi band operation much simpler. The driver ICs generally take a standard 5V TTL input signal. As of this writing, IXYS / DEI appear to provide the most robust driver ICs with respect to RF service. The IXDD414 will drive a single FQA11N90 MOSFET quite well at 7 mHz and below. These devices cost approximately $3.00 each. One driver IC must be provided for each output MOSFET. The DEI DEIC420 will drive up to 5 FQA11N90 MOSFETs on 80 and 160 meters. The DEIC420 currently costs around $31.00.