Vintage Triplett 3256 Frequency Absorption Meter from an SK's estate. $25 shipped, if you'll hunt down the data/docs online.
From the Triplett ad on p.115, 1952 ARRL Handbook, 29th Ed:
A band-switching tuned absorption frequency meter that covers 5 Amateur bands. Has Germanium crystal, and a DC Milliameter
indicator, for greater sensitivity. Direct calibration on panel-no coils to change. Switching permits instantaneous broadband
change. Audio jack provides for monitoring of phone signals-another new feature. Calibration is in megacycles in the following
bands: 3.5-4 MC; 7-7.3 MC; 14-14.4 MC; 21-21.5 MC; 28-30 MC. Coil is removable, and other coils may be substituted for special
bands. Use for checking: Fundamental frequency of oscillating circuits; Presence, order, and relative amplitude of harmonics;
Parasitic oscillations, etc. Size: 7 1/2" x 2 1/2" x 2 1/4". Metal case with gray hammertone enamel finish & black trim.