I have noticed that the antenna switching introduces significant attenuation but some attenuation is expected so time for another look.  In looking at the specs I am not turning on the diodes very hard.  The 74HC14's can source about 4 mA and the diodes really want 10 - 100 mA to turn on hard.  I remember the UDN2983 source driver - an nice solution but obsolete but is available.  There's a LTC 1156 quad high side micropower driver IC and resistors/transistors.  Any other ideas?