English: Top view of the Leutz Transoceanic "Phantom" radio receiver with its cover removed, from 1927. Leutz, C.R., Inc was an American maker based in Altoona PA and/or New York, active in 1921-1931 [1]. The "Phantom" was a 9 tube tuned radio frequency (TRF) receiver, with 4 tuned radio frequency stages, a grid leak detector stage, and 4 audio amplifier stages. The organization of the receiver is obvious from the layout of the parts. The 4 TRF and one detector stages are visible in the shielded compartments from right to left. Visible in each compartment is the triode vacuum tube, the air core interstage coupling transformer, and the variable capacitor which forms the tuned circuit. The 4 audio amplifier tubes are in the righthand compartment. The capacitor for each of the 5 tuned stages is adjusted by a dial on the front panel. To make tuning easier, the capacitors can also be connected together mechanically (ganged) with the horizontal shaft running through the compartments, so they can be tuned together. The meter and two rheostat knobs at the right end of the panel control the filament currents. With plugin coils the receiver can cover the range from 3600 to 35 meters wavelength (83 kHz to 8.6 MHz).

Caption: "THE SHIELDED COMPARTMENTS OF THE RECEIVER - At right are the four low frequency stages in one compartment. The four high frequency stages and the detector stage, each in a separate compartment, are seen to the left of the low frequency compartment. Note also the common shaft of the rotors of the tuning condensers"