I have just aquired a D300, and the output was low on SSB, although it would go from a 2W DK to 6W in AM mode. SSB was peaking at 6W also. I checked the 2166 and the 1969 transistors initially and found both had readings from C to E. Tested 2 new ones and compared and the new ones didn't have the reading. Installed both the new 2166 and the 1969 in the radio and tried to set the driver bias. The not so good Service manual I got from fleabay states the current should be 30mA. The lowest I can get is 105mA. I checked the varister or what ever they are and they are not shorted and read good with the diode tester and ohm meter. Also checked TR38, TR40 which seem to be inline with the driver and final section and they test good on my cheep transistor checker. The capacitors in the circuit also seem to test OK.
The 2166 driver is a replacement for the 2SC1306 I've heard so that's what I used as the suspect driver was already a 2166 when I received the radio.
Receiver section seems to be working exceptionally.
Any help would sure be appreciated.
The 2166 driver is a replacement for the 2SC1306 I've heard so that's what I used as the suspect driver was already a 2166 when I received the radio.
Receiver section seems to be working exceptionally.
Any help would sure be appreciated.