KENWOOD TK7102H
Manual de Servicio

TK-7102H
ADJUSTMENT
Replacing a Drive FET (Q800)
1. When replacing the Drive FET, you must also replace its heat conductor cube, because the heat conductor cube is removed along with the FET. 2. After removing the FET and its heat conductor cube, solder a new Drive FET to the PCB. Make sure the FET is in the proper position before soldering. 3. Attach the heat conductor cube to the FET as instructed below. 5. The solder melts and binds the FET and the cube securely. Then, slide the soldering iron along the PCB surface to cool the soldering down ( r ). If the heat conductor cube comes off from the PCB or the soldering can be seen on the top of the plate, the soldering has not been successful. The soldering must bind the heat conductor cube and FET securely (see the figure 3).
OK Uneven PCB Drive FET PCB Drive FET NG Solder PCB Drive FET

s How to Solder the Heat Conductor Cube
1. Place a piece of soldering wire (about 2.5~3.0 mm long x 0.6mm diameter) into the FET hole on the PCB ( q ). 2. Place the heat conductor cube on the PCB surface beside the FET hole. The rounded surface of the heat conductor cube must face upward (as shown below) ( w ). 3. Slide and drop the cube into the FET hole so that the rounded surface of the cube is now horizontal (as shown below) ( e ).
1 3 2

Fig. 3
6. After soldering the heat conductor cube to the PCB, check the level of PCB surface. The surface of the heat conductor cube must be free of flux and solder. It must be flat and smooth, at the same level as the PCB surface (as shown below).
PCB

PCB Drive FET Q800

Drive FET

Fig. 1
4. Place a heated soldering iron onto the top of the cube, using an iron tip 900M-T-3CF. Hold the soldering iron in position for about 5 seconds (See the figure 2).

Fig. 4 s How to Check the Heat Conductor Cube Surface
1. Slide your index finger along the PCB surface (as shown below) ( t ). The surface should be flat and smooth. If you feel that the surface is uneven because of solder or flux, grind them using meshed copper or re-solder the cube in order to flatten the surface.
5 PCB Drive FET

4

PCB Drive FET

Fig. 2

Fig. 5
45° 3.0mm (0.118") 17mm (0.670")

Test Frequency (MHz)
Channel TX 1 : Center 2 : Low 3 : High 4 5 6 160.100 146.100 173.900 160.000 160.200 160.400 K,M RX 160.050 146.050 173.950 160.000 160.200 160.400 TX 149.100 136.100 161.900 149.000 149.200 149.400 K2,M2 RX 149.050 136.050 161.950 149.000 149.200 149.400

900M-T-3CF

14