UNIDEN GRANT XL Mods: Clarifier Modification
In the diagram above we have shown the stock GRANT XL clarifier circuit before modification for reference. Below we have shown the same circuit after the clarifier circuit has been modified. Please note that these modifications apply only to the first versions of the Grant-XL that were manufactured in the Philippines with serial numbers prior to the 4500 series. Later models that have serial numbers beginning with 4500 have different color wires on the clarifier control. They are as follows , Yellow instead of orange, and Red instead of Blue. The White wire is the same in both models.
1. Locate D52 and R44 in the clarifier circuit and cut one end as shown below. It doesn't matter which end of R44 and D52 you cut. Next locate R174 (12K Resistor) and unsolder and remove it from the circuit. Next solder a jumper wire in place of R174.
2. Next trace the White wire form the clarifier control to where it is soldered to the circuit board, and cut it loose. Resolder the white wire to the circuit board ground.
3. Next trace the Orange wire from the clarifier control and unsolder it from the circuit board. At this point you will need to add a small amount of wire to the orange wire in order to make it long enough to reach pin 3 of IC4 (MB375S Regulator IC). Now solder this wire to pin 3 of IC4. Your clarifier will now track on receive and transmit.
Super Slide Clarifier Modification
In most cases once the clarifier circuit has been modified, the stock clarifier control is just not adequate for all practical purposes. Not only is it difficult to clarify, the unit will also tend to drift off frequency due to the lack of clarifier control stability. The cure for this problem is to install a 10-Turn Precision Potentiometer in place of the stock clarifier control. This will allow you cover the same range in 10 complete turns versus 1 turn with the stock control. Your clarifier will then operate like a FINE TUNE clarifier control and will have much improved stability, with very little or no frequency drift. Below we have shown what the above circuit should look like once modified and how to wire your new 20k- 10 turn pot in place of the stock clarifier control for the Uniden Grant XL.
20K-10 Turn Pot Diagram & Installation Instructions
1. First perform the standard clarifier modification on the previous page.
2. Next unsolder the Orange Wire, Blue Wire, and the White Wire from the stock clarifier control. At this point you will need to remove the old clarifier control and install the new 20K-10 turn pot in its place. Once that you have mounted the new pot, resolder the Orange Wire , Blue Wire, and the White Wire to the new 10 turn pot as shown in the diagram to the'right.
3. You may also want to add a jumper either across or in place D51 lor increased slide. Once completed, your unit should now slide anywhere from 10 to 20 KHz with precision control.