Tuning
Instructions for GE Custom MVP VHF Receiver
By Kevin Custer W3KKC
Preliminary checks and adjustments;
1. Connect signal generator to RX antenna jack on channel frequency.
2. Crystal Frequency = Operating frequency - 11.2 / 9 For low side
injection.
3. Crystal Frequency = Operating frequency + 11.2 / 9 For high side
injection.
4. Oscillator Measurements are made via black meter plug on IF Board,
connect negative lead of volt meter to ground.
5. Check for +10 volts DC on pin 5 of the black plug.
Step | Test Point | Tuning Control | Meter Reading | Procedure |
1 | Pin 3 (Mult-1) | C406 | Maximum | Tune C406 for Maximum meter reading |
2 | C411, C416, C306, C307 | See Procedure | Preset C411 and C416 to a position similar to C406, Preset C306 & C307 fully counter clockwise | |
3 | Pin 4 (Mult-2) | C411, C416, C406 | See Procedure | Tune C411 & C416 for Maximum meter reading, Retune C406, C411 and C416 for Maximum meter reading, Then dip C306 and tune C307. DO NOT READJUST C306 & C307 |
4 | Pin 1 (IF AMP) | C502, C301 through C305 | Maximum | Apply an on-frequency signal to the antenna jack, Keep signal below saturation. Tune C502 then C301 - C305 for maximum meter reading |
5 | Pin 1 (IF AMP) | C502, C301 through C307 | Maximum | Apply an on-frequency signal to the antenna jack, Retune C301 - C305 and C502 for best quieting sensitivity C306 & C307 may also be turned slightly (No more than 1/4 of a turn) |
6 | Pin 2 (FM Det) | L603 | 0.38 Volt | With no signal applied, adjust L603 for a reading of 0.38 Volt |
7 | P903-1(Vol/Sq HI) | L603, R608 | See Procedure | Apply 1000uV signal with 1kHz modulation at 3.0kHz deviation, Tune L603 for Maximum reading then adjust R608 for 1 volt AC RMS |
Tuning locations for GE Custom MVP VHF Reciver (bottom view)
Tuning locations for the GE Custom MVP VHF Receiver (top view).
Original concept and pictures by Matt Krick K3MK
HTML Copyright 2002 Kevin K. Custer W3KKC
All Rights Reserved.