D&A rdx-75 20 meter transmitter

[crazy_179]

Hi, I recently picked one of these up and am looking for the modifications for it. Any help would be appreciated. I tried following the pdx-400 guide but it is quite a bit different. It has 4 6JG6 tubes in it. One driving three I believe. I can post pictures if necessary

 

[bioman]

check the D&A RAIDER schem..........

its probably a straight 4 NOT one driving 3

scott

 

[crazy_179]

check the D&A RAIDER schem..........

its probably a straight 4 NOT one driving 3

scott

Thanks for the reply

i do have the raider schem. I got looking at it and they had jumped a wire from the radio side of the relay to the socket on pin 5 of the final tubes. These three tubes are all wired together on pin 5 and also pin 9 goes off of those three each having their own resistor (100 ohm) if raider schematic is correct, to the z 14 choke. the tube i am assuming is the driver tube does not have that. it is connected to the grid tune admustment with a smaller coil. Also they had jumped down the coils as well. SWR was good but I was not receiving as well as normal with the amp inline. it did key and put out wattage. about 50 watts or so but my watt meter was swinging backwards upon modulation. so i am investigating. trying to copy it to the raider schematic but i do believe the first tube was for carrying the cw carrier to the other tubes.