Merle (Cliff) Rummel, W9LCE, uses an AGS (Aircraft-Ground System or Airport Ground System) receiver system that includes an AGS receiver with crystal filter, the dual power supply, the 58C, two rack panels of coils and the speaker. The AGS rack was marketed as an Airport/Aircraft Receiver System. This particular system includes both ham band coils for 80, 40 and 20 meters and general coverage coils.
W9LCE's 42" table top rack has the AGS receiver on the bottom, the 58C standby receiver is directly above it, then the GDRPU dual power unit, then two rack panels containing 24 coils (1.7 to 18MHz on the AGS and 2.9 to 22MHz on the 58C). At the top is the speaker panel.
The AGS is a 9 tube superheterodyne receiver: RF, Conv, 2 IF, Det, AF, HF Osc, BFO, AVC.
The 58C is a 5 tube regenerative receiver much like National's SW58: RF, Det, 1st AF, dual AF out.