Modification of 5-tone tonemodule TQ5001 or TQ5002 to a (1750Hz) singletone unit (repeater-call).
TQ5001 has a ZVEI tonecoil, and TQ5002 has a CCIR tonecoil.
All components around IC U106 and the IC itself are removed, diodes D105 and D106 and transistor Q130 as well
A new diode is connected from U104 pin4 (cathode) to U104 pin 10 (andode).
All CODING wires on the coil are removed. DO NOT remove the 3 dualcolored wires.
Tonefrequency is selected by new white wire from C113 to terminal on coil.
If the unit is a TQ5002 selecting terminal 10 will output 1747Hz, and if the unit is TQ5001 selecting terminal 9 (as shown on picture)
will output 1830Hz, and then a capacitor (4.7nF) parallel to C113 is used to lower the frequency.
Tone length is adjusted by pot R137 (L adj) and deviation is adjusted by pot R113 (dev adj).
A transistor BC557 and 2 resistors are used to power the LED as a squelch-open indicator.
If a dual LED (red and green) is used, the red is used as squelch-indicator, and the green is powered by a resistor to +8,5v.
With power on and no signal the LED is green, and with signal the LED is yellow.
