Tachometer Type E-4 Weston 545 A-20 Havoc H-21 and all components may not

and all components may not be present

with an antenna wire connect from the top of mast to the top of the tail

made by Maxwell Smith Co

although they could be retrofitted to other models

Tachometer Type E-4 Weston 545 A-20 Havoc H-21 and all components may notHere is a WW2 vintage electrical Tachometer measuring up to 3500 RPM. This is the type used on the Douglas A 20 Havoc attack bomber (see photo of instrument location on the A 20 cockpit panel as illustrated in its flight manual) as well as the C 45 Expeditor transport (both aircraft used 2 each). The anchor symbol of the US Navy appears on the rear of the instrument, so it may have been used in an aircraft of the US Navy. Measures 3. 25 inches