[ARC5] RAK-5 and RAL-5 Receivers

[Robert Eleazer]

>From the US Navy's Electron Magazine of July 1945
It has been found that the carbon resistors used in the bleeder and screen-dropping circuits of the RAK-5 and the RAL-5 receivers are notorious for changing

value. This is apparently due to the fact that they are incapable of withstanding the excessive amount of heat that is generated in these units. If this drift is to a

lower value of screen-dropping resistor, pla.te potential of the receiver may be caused to drop as much as 30 volts, resulting in decreased performance.

This condition is eliminated by changing the 20,000-ohm bleeder resistor R-202 from a 2 waft carbon to a 5 or 10 watt wirewound, and the two parallel-connected

6200-ohm screen-dropping resistors R-203 and R-204 to a single 10 watt 3100-ohm wi·rewound resistor. There is adequate space for the larger resistors above the bakelite

mounting strip from which the original carbon resistors were removed. ;

Also it has a noise suppressor mod for the RBH-1 receiver, if anyone is interested.

Wayne  WB5WSV 


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