When a plug other than the PG-2V or PG-3C is inserted into the DC IN jack, the ground side of the jack may not disconnect. This may cause the external DC power to be supplied directly to the internal battery which results in overheating the battery and blowing the fuse. To protect the battery, replace the fuse with a protection diode, part number ERB83-004.

Note models with serial numbers greater than 801XXXX allready incorporate this diode as D16.

This modification may be performed under warranty.
Time required for this change is 1/2 hour or less.



19-07-1998 144 - 165 TX/RX mod for the TH-205

To open your th-205,215,or 225 all you have to do is take out the screws on the back, and gently open up the front of the unit...
Locate the obvious 4 jumper bridges on the pc board. The bridges are numbered j-1, j-2, j-3, and j-4..Jumper j-3 has already been cut...
Carefully snip jumpers j-1 and j-2 and ever so slightly seperate the snipped bridges to insure no-contact betwen the points.. Reassemble the unit..Look at your instruction manual and reset the microprocessor..The mod will not work until you reset the mpu...
The info. For reset is near the back of the manual..After that the unit is wide open to operate between 144 to 165.



06-01-2000 Expanding TX and RX for Kenwwod TH-205

Remove rear cover from handheld, on the board you will see easily three solder links, bridge the left and the middle links.

Turn the radio back on.
This mod expands the RX more than the TX.

The transceivers mentioned above can be mechanically improved by adding a bracket assembly to the volume and squelch controls. The bracket assembly is being used in current production and is available for older units from the Kenwood Parts Department.

Bracket Ass'y (W05-0235-00)

1. Disconnect the battery pack and antenna.
   
   
2. Remove the 7 screws from the panel of the transceiver (Figure 1).
   
   
3. Lift the front panel from the transceiver and lay it to the right side.
   
   
4. Disconnect the 2 flex cables and remove the 3 screws from the IF unit (Figure 2).
   
   
5. Pull the top panel off and the remove the IF unit.
   
   
6. Remove the knobs and black cloth from the volume and squelch controls.
   
   
7. Inspect the controls to insure they are mounted flush to the board. If they are not flush, completely desolder and resolder the controls.
   
   
8. Insert the bracket over the controls and tighten the nuts (tighten the nut on the volume control first). See figure 3 for the bracket assembly view.
   
   
9. Assemble the transceiver be reversing steps 1 - 6.

This modification may be covered under warranty.
Time required for this modification is ½ hour or less.



16-04-2000 TH-205 Signal-To-Noise ratio improvement
Author: Trio-Kenwood Communication, inc.

During strong signal reception, the noise level may appear to increase due to unstable action of the active filter in the PLL. To improve the sig-to-noise ratio, install a 390 Kohm resistor on the emitter of Q12 (active filter) as described below.

Required parts:
390 Kohm chip resistor (RK73FB2A394J)

1. Disconnect the battery and antenna.
   
   
2. Remove the 7 screws from the back panel of the transceiver (figure 1).
   
   
3. Lift the front panel from the transceiver and lay it to the right side.
   
   
4. Disconnect the 2 flex cables and remove the 3 screws from the IF unit (figure 2).
   
   
5. Pull the top panel off and then remove the IF unit.
   
   
6. Remove the 8 screws from the RF unit and unplug connector CN2 (figure 3). Remove the RF unit from the back cover.
   
   
7. Locate capacitor C82 on the foil side of the RF unit (figure 4).
   
   
8. Solder the 390 Kohm chip resistor directly on top of C82.
   
   
9. Assemble the transceiver by reversing steps 1 - 6.

This modification may be covered under warranty.
Time required for this modification is ½ hour or less.



21-04-2000 TH-205/215/315/415 PTT knob installation procedure
Author: Kenwood Communication, inc.

The original plastic knob (K29-3054-15) has been replaced with a rubber knob (K29-3054-35). The PTT mounting guide on the front panel must be removed to allow the new knob to be installed. The following procedure will explain the installation procedure.

1. Disconnect the battery pack and antenna.
   
   
2. Remove the four screws from the back panel.
   
   
3. Carefully lift the front panel up and lay it into the right side of the body of the transceiver.
   
   
4. Disconnect the front panel from the body of the transceiver.
   
   
5. The plastic PTT knob is held in place with three tabs. Press in the bottom tab and then push the knob out of the front panel.
   
   
6. Push in the guide to crease it's two legs where they join the front panel.
   
   
7. Wiggle the guide back and forth until it breaks off the front panel. Discard the guide and plastic knob.
   
   
8. Install the rubber knob on the front panel. The side with the square tab goes toward the bottom of the front panel.