1953 grid dip meter. The diagram is divided into two parts in case the builder wants to place the power supply in one chassis and the RF portion in another. It is the builder's option as to whether to put the entire meter in one chassis or two. Although the connections between the two sections are not numbered in the print diagram they will be referred to by numbers here to avoid confusion. One prong of a two prong power plug goes to the bottom end of the primary of a power transformer, see text. The other prong goes through a switch then a fuse to the top of the primary. One side of the 6.3 volt heater winding connects to chassis and also to connection point 3. The chassis ground from the power supply connects to connection point 2. One side of the 120 volt secondary goes to chassis ground. The other side goes to the anode of a rectifier, updated to a 1N4007 silicon diode. The cathode of the diode goes to the positive side of a 22 u f 250 volt capacitor. The negative side goes to chassis ground. The diode cathode also goes to the clockwise end of a 100 k ohm pot. The other side goes to chassis ground. The wiper of the pot goes to connection point 1. Connection point 4 goes to the negative side of a 1 m A meter. The positive side goes to chassis ground. This completes the power supply and metering chassis.

On the RF side connection point 1 goes to one side of a 0.01 u f capacitor. The other side of the capacitor connects to chassis ground. The chassis ground goes to connection point 2. Connection point 1 also goes to pin 1, one of the plate pins, of the tube, 6 C 4. The other plate pin, number 5, also is bypassed to ground through a 0.001 u f capacitor. The grid, pin 6, goes through a 100 p f capacitor to stator of a single 50 p f variable capacitor. The rotor and frame of the capacitor are grounded. The junction of the fixed and variable capacitor goes to pin 1 of a connector socket. Pin 1 of the mating plug goes to the top end of a coil. This represents the coils that are plugged in to select the frequency range. A tap on the coil, near the bottom, connects to pin 2 of the plug. Pin 2 of the socket goes to the cathode, pin 7 of the tube. The bottom end of the coil goes to pin 3 of the connector plug. Pin 3 of the socket goes to ground. The grid of the tube also connects to one end of a 22 k ohm resistor. The other end of this resistor goes to connection point 4. Connection point 4 is also bypassed to chassis ground through a 0.01 u f capacitor. One side of the tube's heater goes to chassis ground. The other side of the heater is bypassed to chassis through a 0.01 u f capacitor. This side of the heater goes to connection point 3. End of verbal description.
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