148NWST ALIGNMENT

REVISION: 1.111

ALIGNMENT

PROCEDURE
MODELS: 148 GTL 148 GTL ST 148 NW ST REVISION: 1.111 DATE: 03/11/03

PREPARED BY:

Total Pages: 8 pages

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print date: 3/27/06
148NWST ALIGNMENT INSTRUCTION

1 TEST CONDITION:

C 13.8VDC CH19 (27.185MHz) 1mV CB 30% SSB 500Hz and 2400Hz 0.5W 1S pulse @ 100mS and 1V peak-to-peak amplitude, with rise and fall time of less than 10nS. FREQ. (MHz) 27.215 27.225 27.255 27.235 27.245 27.265 27.275 27.285 27.295 27.305 27.315 27.325 27.335 27.345 27.355 27.365 27.375 27.385 27.395 27.405 1.0. TEST TEMPERTAURE: 1.1. STANDARD DC POWER: 1.2. MEASUREMENT CHANNEL: 1.3. STANDARD AUDIO LOADING: 1.4. ANTENNA IMPEDANCE: 1.5. STANDARD RF INPUT: 1.6. STANDARD REF. MODULATION: 1.7. STANDARD REF. AUDIO OUTPUT: 1.8. PULSE GENERATOR: 1.9. FREQUENCY TABLE: CH NO. FREQ. (MHz) 26.965 26.975 26.985 27.005 27.015 27.025 27.035 27.055 27.065 27.075 27.085 27.105 27.115 27.125 27.135 27.155 27.165 27.175 27.185 27.205 CH NO. 39 40

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1.9. TEST EQUIPMENT SETUP AS BELOW: A. TX test equipment setup:

Spectrum Analyzer

Power Supply

Modulation Meter

Dummy Load

148NWST

RF Wattmeter

Audio Gen.

B. RX test equipment setup:

AC VTVM

RF Signal Generator

Oscilloscope 148NWST

4 ohm Load

Noise pulse generator

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STEP 2.2 STEP 3

MAIN ALIGNMENT VCO Alignment PRESET TO RX mode, AM, CH1 RX mode, AM, CH19 Same as step 2 RX mode, AM, CH19 Voicelock Midrange RX mode, LSB, CH19 Voicelock Midrange RX mode, USB, CH19 Voicelock Midrange Carrier Alignment PRESET TO TX mode, AM, CH19 RX mode, LSB, CH19 RX mode, USB, CH19
CONNECTIONS DC voltmeter to TP9 Oscilloscope to TP10 Oscilloscope to TP1 Frequency counter to TP1 Frequency counter to TP1 Frequency counter to TP1 CONNECTIONS Frequency counter to cathode of D17. Disconnect TP7 & TP8. Frequency counter to TP14 Frequency counter to TP14
ADJUST L19 L21 L20 L23 L22 L59
PROCEDURE Adjust for 3.2V, 0.1V Check CH40 = 4.2V, 0.2V Adjust for maximum output Adjust for maximum output Adjust for 34.985MHz Adjust for 34.9835MHz Adjust for 34.9865MHz

ADJUST L31 L30 CT2

PROCEDURE Adjust for 7.8MHz, then re-connect TP7 & TP8 Adjust for 7.7985MHz Adjust for 7.8015MHz

STEP 1

RECEIVER ALIGNMENT Connect an AC VTVM across speaker coil. Adjust volume control to obtain a suitable indication. Set generator output low enough to prevent AGC limiting. Preset controls as follows, unless otherwise noted: RF Gain maximum, Voicelock midrange, Squelch minimum, NB/ANL off, Tone normal. PRESET TO CONNECTIONS ADJUST PROCEDURE Output of signal generator through L7, L8, L9, RX mode 0.01F to TP16 (TR15 emitter). L10, L12, Adjust for maximum output CH19, USB Freq. = 7.8005MHz L14 NO modulation, RF output 200V Output of signal generator through RX mode 0.01F to TP15 (FET1 Gate 1). L15, L13, Adjust for maximum output CH19, AM Freq. = 455KHz, 1KHz 30% L3 modulation, RF output 100V Output of signal generator to RX mode antenna input. L4, L5, L6 Adjust for maximum output CH19, AM Freq. = 27.185MHz, 1KHz 30% modulation, RF output 1V

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STEP 4
PRESET TO RX mode CH19, AM NB/ANL switch set to NB RX mode CH19, AM Squelch to maximum RX mode CH19, AM RX mode CH19, USB
CONNECTIONS ADJUST Output of signal generator and noise pulse generator to antenna input. Freq. = 27.185MHz, 1KHz 30% L1, L2 modulation, RF output 1V. Oscilloscope to TP17. Output of signal generator to antenna input. VR3 Freq. = 27.185MHz, 1KHz 30% modulation, RF output 1800V Output of signal generator to antenna input. VR1 Freq. = 27.185MHz, 1KHz 30% modulation, RF output 100V Output of signal generator to antenna input. VR2 Freq. = 27.186MHz, no modulation, RF output 100V
PROCEDURE NOISE BLANKER Adjust for maximum pulse amplitude on oscilloscope SQUELCH RANGE Adjust until audio just appears AM SIGNAL METER Adjust for a reading of 9 on the analog meter of the CB radio SSB SIGNAL METER Adjust for a reading of 9 on the analog meter of the CB radio

4.0 STEP 5 6

Transmitter Alignment Maintain a 50 ohm 25 watt dummy load on the antenna connector for the following steps. PRESET TO CONNECTIONS ADJUST PROCEDURE TX mode L47, L48, RF wattmeter to antenna CH19, AM L46, L45, Adjust for maximum RF output input Dynamike minimum L38 Spectrum analyzer to Adjust for minimum at 54MHZ Same as step 1 L36 antenna input (2nd harmonic) TX mode RF wattmeter to antenna CARRIER BALANCE CH19, USB VR7 input Adjust for minimum RF output Dynamike minimum DRIVER BIAS Same as step 3 Insert ammeter at TP8. VR9 Adjust for 25mA FINAL BIAS Same as step 3 Insert ammeter at TP7. VR8 Adjust for 50mA TX mode RF wattmeter to antenna CH19, USB input. Insert a SSB ALC VR11 Dynamike maximum two-tone, 500mV signal Adjust for 12 watts PEP RF output to microphone input. TX mode RF wattmeter to antenna AM CARRIER POWER CH19, AM VR10 input. Adjust for 4 watts RF output Dynamike minimum

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STEP 10

PRESET TO Same as step 7

CONNECTIONS

ADJUST VR6 VR5 VR501

Frequency counter to antenna input. Modulation meter to TX mode antenna input. Insert a CH19, AM 1KHz, 50mV signal to Dynamike maximum microphone input. Remove the dummy load. Connect a 100 ohm load to the antenna CH19, AM input. Use the built-in SWR meter to check the SWR. Same as step 7
PROCEDURE RF POWER METER Adjust so that the needle of the CBs analog meter is at the border between the green and red zones. TX CARRIER FREQUENCY Adjust for 27.185MHz AMC CONTROL Adjust for 90% modulation
SWR METER Adjust for an SWR reading of 2