I believe that D8 is the anti-spiking diode next to the big transformer in the radio , it is there for a reason ! jumping it might give you 1 extra watt if that ,but can cause other problems for the radio in the long and short of it. IM not here to start a pissing match either. Folks jump them all the time , I did at one time and until something burnt up on a radio one time and i couldn't figure it out for the life of me ? alls I know is that when the radio took a shit ,the big transformer was hotter then a clothes Iron !! that was a first and I never jumped those diodes ever again !! for one lousy watt extra !! BS !! You want to do a swing mod ? that's fine and dandy !! I would highly suggest to anyone ,that jumping the anti-spiking diode is truly a bad Idea and it just aint worth the life of the radio for 1 lousy extra watt.