Midland 77321 Manual

CB Module Tuning Procedure

1. RX TUNING

1.VCO

Adjust TC 20P variable capacitor till tolerance of 10MHz reference point is within ±

100Hz.(measure at TP8 by cymometer)

Adjust T12 coil, let VCO output is 1.9V ±0.2V at 40CH.(Measure point is at TP3 by

mechanical Voltage meter)

2. TX.

Press TEST BOX AM/FM button to switch between AM and FM

2.1 AM/FM: Press PTT, adjust TC (Frequency Tolerance TUNING), so that the

output frequency is similar to desire channel such as 27.405MHZ for channel 40.

2.2 AM: adjust VR2 (AM MODULATION TUNING) to let AM MOD at 80%~85%

and MAX is not over 100%.

2.3 AM/FM: tune T6 T7 T8 and VR200(TX POWER /TX DIST TUNING) to adjust

the TX POWER and find out the distortion is minimum point. (AM AT 80% MOD,

DIST is less than 10%; FM DIST is less than 8%). After that we have to tune the TX

Power within 3.6W to 4W by adjusting VR200.

2.4 FM: Adjusting VR4 (Frequency Deviation) to let FM frequency shift between

1.7K~1.9K and Maximum is not over 2K.

3. RX TUNING

. Press TEST BOXAM/FM button to switch between AM and FM.

3.1 AM/FM:Adjust L1~L3, T1, T2 to make the best sensitivity and S/N. It should be at

12dB SINAD and the S/N is at least –109dB..

DC 12.7V

Test Box

SAMPLE

RF Communications

Spectrum Analyzer

3.2 FM : AdjustT3(SENSITIVITYAND S/N) to let the SINAD be the best..

3.3 AM/FM : Adjust VR1(AUDIO OUTPUT) to let the audio output for FM

0.1~0.32V and AM 0.12~0.16V

3.4 Adjust VR20(SQ), when INPUT is 62dBuV and OUTPUT would be 3.8V.

Testing Point is at TP1.

2.WX Tuning

Description: WX is just a 1050Hz signal warning system.

A. Frequency reference point is as TP5. It should be 10.25MHz ±60Hz.

B. The voltage at TP6 should be 1.5 to 1.75V. If not, tune L6 till get the desired value

C. Set the testing point at the output of TP4, tune T4 till getting maximum sensitivity

and minimum distortion.

D. Set the testing point at TP10 for 1050Hz signal testing. Usually, voltage at TP10

should be high (4.9V). Upon receipt 1050Hz signal, the voltage should be low (0V).

The above testing is following ETS300-135 standard for FM, EIA/TIA-382-A for AM

including ( FCC/CE and client requirement)

PREPARED BY : Mr. YK Liu APPROVED BY :

Date: 6-Apr-05

Table of contents

Other Midland Radio manuals

Midland

Midland 70-1526A User manual

Midland

Midland MXT575 User manual

Midland

Midland 1001LWXA User manual

Midland

Midland ALAN 121 User manual

Midland

Midland 248XL User manual

Midland

Midland GXT760 series User manual

Midland

Midland PRO902 User manual

Midland

Midland 75-509 User manual

Midland

Midland LXT210 Series User manual

Midland

Midland BIZTALK MB400 Installation manual

Midland

Midland 278 User manual

Midland

Midland CB-1 User manual

Midland

Midland 4001 User manual

Midland

Midland Syn-Tech II User manual

Midland

Midland 1001z User manual

Midland

Midland Radio ER300 Manual

Midland

Midland X-TRA TALK GXT Series User manual

Midland

Midland G9 User manual

Midland

Midland ER310 User manual

Midland

Midland X-tra Talk LXT118 Series User manual

Midland

Midland WR-100 User manual

Midland

Midland WR-100 Operating instructions

Midland

Midland 70-050 User manual

Midland

Midland ML801 User manual

Popular Radio manuals by other brands

EisSound

EisSound KBSound iSelect user manual

Konig

Konig HAV-SR41 manual

Roberts

Roberts exprssion manual 

VDigi

VDigi DD3.0 Operation manual

Radio Shack

Radio Shack 21-1863 owner's manual

Roberts

Roberts Stream 207 instruction manual

Sony

Sony Walkman SRF-M97 Service manual

Stanley

Stanley FatMax FMC770 manual

auna

auna DAB-Radio 10026947 manual

SOUNDMASTER

SOUNDMASTER UR190 instruction manual

HYT

HYT TC-320 user manual

auna multimedia

auna multimedia Yellowstone 10026851 instructions

B-Tech

B-Tech GMRS-V2 manual

Weierwei

Weierwei VEV-V8 user manual

SOUNDMASTER

SOUNDMASTER DAB750 instruction manual

Telefunken

Telefunken TF-1505 instruction manual

Makita

Makita LXRM03 instruction manual

PRESIDENT

PRESIDENT TEDDY R. owner's manual