10-27-2013, 05:26 PM
Does the localizer control have any effect on the overloading?
This pot sets the level of bias on the RF and IF tubes with no signal by setting the resting grid voltage of the 24 AGC tube. The 24 grid is also connected to the cathode of the 27 detector. When a signal is received, the 27 cathode goes more positive, making the 24 plate less positive. The 24 plate is coupled to the grids of the RF and IF tube, so their grids also less positive thereby increasing their negative grid bias. This reduces the gain of the RF and IF which provides the AGC action.
The whole AGC system depends on the correct voltages on all the controlled tubes, so if the voltage is off anywhere in the circuit, it will throw everything off and the set will overload.
This pot sets the level of bias on the RF and IF tubes with no signal by setting the resting grid voltage of the 24 AGC tube. The 24 grid is also connected to the cathode of the 27 detector. When a signal is received, the 27 cathode goes more positive, making the 24 plate less positive. The 24 plate is coupled to the grids of the RF and IF tube, so their grids also less positive thereby increasing their negative grid bias. This reduces the gain of the RF and IF which provides the AGC action.
The whole AGC system depends on the correct voltages on all the controlled tubes, so if the voltage is off anywhere in the circuit, it will throw everything off and the set will overload.
