ChVar. The 13C PA band coil sets were delivered with a condenser , p.e. "4000 mmF . The available schematic does not show this capacity. 1. Was the condenser connected parallel ovver the coil poles, parallel to a part of the coil , or how ? 2. Was the condenser a single double pole , or 3 pole design with the central pole earthed ?. I do btw not think that a 100-50 W PA dissipation played a major role for range. illustration : during the Battle of Britain , Aug- Sep 1940 , the entire communications circuit over southern England was handled by TR9-D HF transceivers installed in all fighter airplanes (Spitfire , Hurricane) and all interceptors (Beaufort etc.) . TR9-D RF output was 0.5 Watts (PA anode current 25 mA) from dry battery powered valves (Xosc-PA mode , AM) and the system worked flawless day and night. Aerials were long single wire , frequencies 4.3 - 6.9 mc/s . The receiver was of Det- 2 x AF fashion. The HF system became obsolete , only after the introduction of TR 1143 VHF radios (USA SCR 522) later in the war. The WE radio o/b NR 16020 was comparable to the BC 375-191 (MO-PA) in powerful installations of WW II USA B-17´s etc. Probably the laesio enormis of the Earhart crew was to rank DR-Celestial in the primary , and RDF in the secondary row of importance from the beginning , not against the end of the flight.