2H21 and 5593 - Magnetically controlled "Phasitron" phase modulator tubes[3] used in early FM broadcast transmitters.[4][5] 6090 - 18-channel analog demultiplexer for telecomms receiving channel banks, an electrostatic deflection field determines which one out of 18 anodes receives the electron beam controlled by a common grid[6] 6170 and 6324 - 25-channel analog multiplexer for telecomms transmitting channel banks, a rotating magnetic deflection field determines through which one out of 25 grids the electron beam passes to the common anode[7] 6462 Magnetic pickup tube, a 1-axis magnetometer with approx.