DK9IP - MLA2500 Modification

Converting the Dentron MLA2500 amplifier to 2 x 3CPX800A7 tubes

by Winfried Kriegl DK9IP/KH7CD (November 2007)

I got hold of a Dentron MLA2500 some years ago. The price was good but the 8875 tubes were bad and I decided to modify the amp for 2 x 3CX800A7 tubes which has the same socket as the 8875. The tubes used are 3CPX800A7 "pulls" from Tom, WA8WZG.

The conversion was made using a separate heater transformer which was mounted on the back panel. A pressurized Anode compartment was made from epoxy PCB material and a radial blower was mounted to replace the original fan.