Kaar Marine Radio Receiver, 1939

Marine Radio Receiver by Kaar Engineering Company, Type 4AY, Serial Number 17. Only ten of these receivers were made. John Kaar buit a prototype as a companion to a low-power marine radio transmitter already in production, but since his own company already had too much work, Kaar negotiated with fellow Stanford alumnus S.W. Gilfillan in Los Angeles to build the receiver.

Roy A. Borgerson, the original donor of this item, noted the following to the Perham Foundation: “Nameplate says Type 4AY, serial number 17 but this is in error as the chassis is stamped otherwise. This radio was designed by John M. Kaar in 1939 to be a companion receiver to a Low Power Marine Transmitter then being made. Mr. Kaar built the prototype, serial number 11, and then since the company had too much work on hand, Mr. Kaar negotiated with Mr. S. W. Gilfillan of Gilfillan Brothers in Los Angeles for them to build ten of this “Type 4”.

Gilfillan was a Stanford graduate as was Kaar and on this common interest Mr. Gilfillan accepted the order from the young (3 years old) Kaar Engineering Company, although it wasn’t much of an order. This is one of those receivers. It was for operation from a 6 Volt battery, as the suffix on the Type number being “X”. The power requirement on KE equipment for many years was indicated the type No. suffix, i.e.: X=6 Volts, Y=12 Volts, W=32 Volts, V=110 Volts DC, A=117 Volts AC. Combinations such as AY meant that it would operate from both sources. Except “Z” meant 6 Volt battery & 117 Volt AC.”

Kaar Marine Radio Receiver
Interior of the marine radio receiver, Type 4AY, Serial Number 17 (Perham Collection of Early Electronics)