The Radio Information Board

Im using a Bird model 43 wattmeter with a 25-50mhz slug , can I use it at all between 3-20mhz ?? I get a SIGNIFICANT loss of power on the low freq and Im wondering if its my rig or just the wattmeter. I get 15 watts on 80m , 30watts on 40 , 75 watts on 15 and 100 watts on 20 and above. Jeff4570@aol....

Any experience with the solid state finals (or RF package) in the FT840 creating spurs when on an antenna but not on a dummy load ?
Any history of RF problems with this model ?

Im new to this rig , just found out it doesn't work on FM Mode , I get RF RX indication but no RX audio and no transmit carrier . THe manual speaks of a FM-747 optional narrow band FM board , does this mean thats the board needed to operate FM on 10m ??? Afterall it doesn't say anything about WIDEBA...