The portable was the PRC-21, and there were mobiles that used the pencil tubes in modules too, especially the Rx. I> >Contain subminiature tubes (5678, 1AD4, 5783, 5840). > >All are marked "152-174 MC". > >I have 3 modules: Local Osc / RF Ampl / 2nd IF Discr. > > > >Was wondering what equipment these would be from. > >