PROTECTIVE COVER

Remove the chassis cover. Caution: There is live voltage when power is applied.

TUNE UP PROCEDURE FOR POWER LEVEL

For this output power level tune up procedure, it is assumed that the PLL frequency synthesizer is functioning properly. The entire PLL circuitry (including two crystal oscillators, VCO, frequency dividers, low pass filters and the phase detector) is sealed in metal shield. The PLL section alignment procedure will be explained afterward.

Power supply voltage is 1 17V 60 Hz A.C. Connect an R.F. wattmeter (50 ohm) to the antenna connector.

Set transceiver to Channel 19 (27.185 MHz).

Refer to interior parts location drawing in instruction book for the following adjustments.

1. Depress microphone button and adjust cores of L301, L302, L303, L304, L305, L306, L307, and L308 for miximum reading on the wattmeter.

2. Check output power on all channels. If not equal, readjust L302, L303, L304, and L402.

3. Adjust L307 and L308 for optimum maximum wattmeter output.

4. Adjust RV 603 for reading on transceiver power meter equal to indication on the wattmeter.

5. At factory C314 (nominal value of 82 pfd) is selected for maximum R.F. power level.

6. Located behind the P.C. board containing the VACCUM tubes is a shielded can containing the final R.F. amplifler tank circuit. There are two variable capacitors are mounted on top of tank coil. Peak these for maximum output. These capacitors interact so it will be necessary to adjust and readjust until maximum reading is obtained on R.F. output meter.

PLL CIRCUiT ALIGNMENT PROCEDURE:

1. Set transceiver in Transmit mode.

2. Connect oscilloscope D.C. probe to T.P. 1

3. Adjust L403 and observe the D.C. level swing between zero volts to 8 VDC. Then set the level at 7VDC when channel selector is set at Channel 40, (Note when channel selector is switched to 1. the level will jump to about 3-4VDC.)

4. With frequency counter measure VCO frequency at P408 against the chart. As an example, the channel 1 Transmit VCO should be 16.543 MHz. When changed to channel 1 Receive mode, the VCO frequency will be 16.27 MHz.

RECEIVER ALIGNMENT PROCEDURE

Set volume to maximum. Selector to Channel 19.

455 KHz I.F. alignment

1. Connect A.C. VTVM to speaker terminals.

2. Connect signal generator to DRAIN of Q105 (Through about 0.01uF capacitor)

3. Set signal generator to 455KHz ± 0.5 KHz

4. Apply power to unit and adjust signal generator output to produce a reading of 0.5 volts on the A.C. VTVM.

5. Adjust L105, L106 and L107 for maximum output on VTVM.

Note: Reduce output of signal generator as necessary to keep VTVM reading around 0.5 volts.

I.F. 10.695 MHZ

1. Connect A.C. VTVM to speaker terminals.

2. Connect signal generator to the base of transistor Q102.

3. Set signal generator to 10.695 MHz (±1 KHz).

4. Adjust L103 and L104 for maximum output as read on VTVM. Reduce signal generator output as necessary to keep the VTVM reading around 0.5 volts.

R.F. ALIGNMENT

1. Connect A.C. VTVM across speaker terminals.

2. Connect signal generator to antenna connector.

3. Set signal generator to 27.185 MHz, modulated 30% with a 1-KHz tone. Set signal generator output to 10uV.

4. Set transceiver to Channel 19 and vary signal generator frequency around 27.185 MHz to produce a maximum reading on the A.C. VTVM. Leave generator at this point.

5. Adjust L101, L102, and L401 to produce maximum output on A.C. VTVM.

6. Reduce generator output to approximately 1uV. Adjust L101, L102, L103, L104, L105, L106, L107 L107, and L401 for maximum reading on VTVM. Repeat until no further improvement noted.

7. Adjust RV102 for “S-9” reading on the transceiver meter with 100uV signal input.

8. Squelch Adjustment. Adjust input signal to 60 dB (1mV) from signal generator, and turn squelch control full clockwise; adjust RVlOl until signal just breaks through.