a. Turn the equipment ON as outlined in steps a. and b. paragraph 3.2.3.
 
       b. Tune a communications receiver to WWV at 10 mc. The BFO in the receiver should be OFF.

       c. Rotate the BAND switch to 80 meter band. (lowest scale)

       d. Rotate the TUNING dial to 4.0 mc.

       e. Rotate the CW-CAL-PH control to CAL. This turns the VFO, buffer, first and second multiplier stages ON so that a calibration signal can be heard. Close the telegraph key.
 
        f. Continue to rotate the TUNING dial about 4.0 mc until the calibration signal is zero beat with WWV.

        g. Turn the FIDUCIAL screw until the hair line is on 4.0 mc.

        h. In like manner, the dial can be calibrated on 15,000 kc by setting the communications receiver at WWV on 15 mc and the 32V-3 TUNING dial at 15 mc on the 20M BAND position. See the following table,

 
 

WWV Frequency	Dial Setting	Oscillator Frequency	Oscillator Harmonic
10 mc	4000	2000	5th
15 mc	15,000	1,875	8th
15 mc	7,500	1,875	8th

 

3.2. OPERATION.

3.2.1. GENERAL. - Operation of this equipment is exceedingly simple once the functions of the controls are understood. The function of the controls is hereby given, followed by a step-by-step procedure for operation of the equipment.

3.2.2. FUNCTION OF CONTROLS.

       a. BAND SWITCH. - This control selects the proper tuning elements for all stages of the amateur band upon which operation is desired. The knob rotates 180 degrees between adjacent bands. Clockwise rotation selects higher frequency bands. The band selected is indicated by the band lighted slide rule dial.

       b. TUNING Control. - This control operates both the slide rule dial and the vernier dial to select the exact frequency upon which operation is desired.

       c. CW-CAL-PH Switch. - This three-position switch selects the type of emission required. In the CW position, the secondary of the modulation transformer is short circuited, the screen voltage is removed from the modulator tubes, a bleeder is placed between the PA screen grid to ground and the carrier-control relay is connected so that it can be operated by the HV switch. The transmitter is ready for CW operation when the key is inserted in the KEY jack. In the CAL position, the VFO, buffer, and three multiplier stages are in operation to supply a signal of suiteble strength for zero-beating against received signals without causing interference to other stations. The carrier control relay is disconnected from the HV switch so that the associated receiver and antenna changeover relay will be in the "Receive" condition. In the PH position, the switch opens the short circuit on the secondary of the modulation transformer, closes the keying circuit, applies screen voltage to the modulator tubes and connects the carrier control relay so that it can be operated by the HV switch or a push-to-talk switch on a microphone.

       d. METER Switch. - The METER switch selects various circuits to be metered by the meter directly above the switch. This meter has 3 scales: 0-250; 0-500 and 0-1000. The table below indicates how it is used:

       e. AUDIO CAIN. - This control adjusts the level of modulation in phone operation.

       f. LV Switch, - The LV switch turns on the filaments and the low voltage plate and bias supply. (Plate voltage is not applied to the r-f exciter tubes, however, until the HV switch is turned on, except when the CW-CAL-PH switch is on CAL position.)

      g. HV Switch. - The HV switch turns on the high voltage supply and connects plate voltage to the r-f exciter tube through operation of carrier control relay K301, The push-to-talk connections are in parallel with this switch.

       h. FINAL TUNlNG. - This control is used to obtain resonance of the PA plate circuit. It must be reset after each adjustment of the ANT. LOADLNG controls.

       i. ANT. LOADING. - This control is used to obtain correct antenna tuning and loading. Start with this control in position number 1. Usually the 80-meter band will load up on position 1, 2, or 3, the 40-meter band on 4, the 20-meter band on 5, the 15-meter band on 6, and the 10 and 11-meter bands on position 6 of the loading control.

       j. TUNE-OPERATE SWITCH. - This switch inserts some resistance in the primary of the power transformer in the TUNE position to reduce plate voltage during the tuning procedure. This switch should always be used to protect the power amplifier tube in off resonance conditions.

       k. FIDUCIAL. - This control, a small screwdriver adjustment located directly under the CW-CAL-PH knob, is used to move the vernier dial index during calibration adjustments.  Once it has been set, further adjustment will be unnecessary over long periods of time.

       1. 600 - 700 v SWITCH. - This switch, located at the rear of the chassis, is used to select either 600 or 700 volts (approx.) for application to the plate.

3.2.3. OPERATION PROCEDURE.

       a. Operate the LV switch to the 0N position. Allow two minutes for the tubes to heat.

       b.         Turn the AUDIO GAIN to the counterclockwise stop. (off)

       c.         Turn the ANT. LOADING control to position 1. (minimum loading)

       d.  Place the CW-CAL-PH control in the position indicating the desired emission.

       e. Rotate the BAND switch to the band containing the desired operation frequency.
 
       f. Rotate the TUNING dial to the desired frequency.
 
       g. Place the Meter selector switch in the GRID position and close the telegraph key. (If PH emission was selected, it will not be necessary to close the key.)

       h. Place the TUNE-OPERATE switch in the TUNE position.

       i. Observing the FINAL PLATE meter, turn the HV switch ON and quickly turn the FINAL TUNING to resonance, i,e. minimum plate current dip.

       j. Observe the GRID current reading on the right hand meter. This should be between 5 and 15 ma.

       k. Operate the ANT. LOADING control clockwise until approximately 125 ma loading is obtained while keeping FINAL TUNING at resonance. Repeat this procedure until 125 ma reading is obtained with complete resonance of PA.  If it is impossible to load to 125 ma PA plate current, rotate the ANT. LOADING control clockwise until proper loading is btainable.

       1. Place the TUNE-OPERATE switch in the OPERATE position and load the PA to 180 ma with the ANT. LOADING control maintaining resonance with the FINAL TUNING control.
 

WARNING

       Operation of this equipment involves the use of high voltages which are dangerous to life. Observe all safety regulations. Do not change tubes or make adjustments inside equipment with the high voltage supply ON. Do not depend upon door interlocks for protection but always turn the high voltage supply OFF. SWITCH TO SAFETY.

       m. If CW emission is selected, the telegraph key can be opened and the transmitter keyed. If PH (phone) emission is selected, turn the METER switch to MOD. and observe the static (resting) modulator plate current. This should be about 50 ma for the 800 v position of the 600 - 700 v switch at rear (55 ma on the 700 v position). While speaking in normal tones into the microphone, advance the AUDIO GAIN control until the modulator plate current swings to about 100 ma on peaks. This will result in approximately 100% modulation with voice input. If desired, a more exact check of modulation level can be made with an oscilloscope while observing the proper meter swing for the voice of the individual operator.

       With sine wave input, the modulator plate current will read about 200 ma for 100% modulation.
 

      With the METER switch set to MOD. IND, a slight kick of the needle indicates approximately 100% modulation on voice peaks. This is useful as an alternate method of indicating modulation level since no deflection occurs on the meter until the modulation level reaches approximately 55%. The level at which the meter kicks depends somewhat upon the loading of the final amplifier and characteristics of the modulator tubes.
 

In step g. above, the key plug can be pulled from the key jack since this is a closed circuit type jack.

CAUTION

When changing BANDS, place the HV switch in the OFF position. Also place the PUSH-TO-TALK switch in the OFF position.
 

If the 800 - 700 v switch is placed in the 700 v position, the PA plate current should be 220 ma.
 

3.2.4.  TYPICAL METER READINGS. (PH position withnout modulation. )
 

POSITION OF S305	LV	HV	GRID	MOD	FINAL PLATE BOTH PHONE & CW
600 v	240	580	10	50	140
700 v	240	720	10	55	200

 

3.2.5. DIAL CALIBRATION. - when changing BANDS, the proper scale on the slide rule dial is illuminated automatically as the BAND switch is rotated. At the same time, the vernier dial fiducial moves up or down the vernier dial face and stops at the corresponding scale to which the slide rule dial is positioned.

       The dial is read by combining the vernier dial reading with the slide rule dial reading. The exact method varies somewhat for the low frequency bands and the high frequency bands and can best be learned by referring to figure 3-2.

3.2.6. ANTENNA LOADING TABLE. - This table indicates the approximate position for the antenna loading control when loading into various antenna impedances on the different bands.

POSITION OF ANT. LOADING CONTROL (for resistive loads)
 

FREQ MC	26 ohm LOAD	50 ohm LOAD	100 ohm LOAD	300 ohm LOAD
3.5	2	2	2	2
4.0	3	3	3	4
7.0	4	4	4	4
7.3	4	4	4	4
14.0	5	5	5	5
14.4	5	5	5	5
21.0	6	6	6	6
21.45	6	6	6	6
27.2	6	6	6	6
28.0	6	6	6	6
29.7	6	6	6	6