


Campbell vibrating reed frequency meter, 1896
1896

Record frequency meter

BBC EP14/1 Audio Test Set
1972

Electrical frequency meter
circa 1900

Frequency Meter BC-221-M
1944

Ferranti frequency meter

Ferranti electric frequency meter

Ferranti Frequency Meter
1940-1960

One German Frequency Meter Type WIK, 30-375 Mc/s.

Frequency meter
1960-1969

frequency meter
circa 1891

Reed frequency meter, 26 to 74 cycles per second

Portable vibrating-speed frequency meter by Elliott

Frahm resonant reed frequency meter, model 4957

Ferranti frequency meter

Frequency meter. German.

Frequency meter

Ferranti frequency meter
Resonant reed frequency meter
1965-1979
Frequency meter by Siemens
1897