LOT 32 PCS CASE NOS Raytheon 4D32 Tubes Collins, Hallicrafters, transmitters $480.00 - PicClick
MCINTOSH 640 tube type RK-4D32 I had to do some digging and ultimately had to go to Sidney Corderman, VP Eng., to get some info. Those amps … | オーディオ, 音響機器, テクノロジー
1 X NOS RAYTHEON RK-4D32 TUBE N.R | #135206899
4 LOT RAYTHEON JAN 4D32 Vacuum Tubes for Collins Hallicrafters Johnson Xmtrs. £281.81 - PicClick UK