Clock Back-Up Battery Replacement Mod.
Many people around the world are finding that the clock back-up battery (BT381) is failing if the rig is not connected to a power source for some weeks, I have two of these rigs and they have both failed.
The battery fitted is a tiny re-chargeable type and I saw no point in replacing it with the same battery as obviously the same will happen again. I decided to fit a CR2032 non rechargeable Lithium type which is considerably larger and is fitted into a suitable socket to facilitate future replacement, there is plenty of room available to fit this near it's original location.
Firstly remove the lower cover of the transceiver, the PCB shown below will be seen and the battery can be located near the front of the board just behind the SD card socket.
The negative terminal of the new battery socket is soldered to a suitable solder tag and screwed down using the convenient PCB fixing screw in the corner of the board thus providing some mechanical rigidity, A small diode (1N4001 etc) must be fitted between the positive battery terminal and the positive battery PCB land where the original battery was located. Because of the fragility of the positive connection on the PCB a VERY thin wire must be used to connect this point to the cathode of the diode which I mounted under the battery socket, on no account try to fit the diode directly to the PCB land as it will fail very quickly.
PCB showing the battery.
The battery fitted is a tiny re-chargeable type and I saw no point in replacing it with the same battery as obviously the same will happen again. I decided to fit a CR2032 non rechargeable Lithium type which is considerably larger and is fitted into a suitable socket to facilitate future replacement, there is plenty of room available to fit this near it's original location.
Firstly remove the lower cover of the transceiver, the PCB shown below will be seen and the battery can be located near the front of the board just behind the SD card socket.
The negative terminal of the new battery socket is soldered to a suitable solder tag and screwed down using the convenient PCB fixing screw in the corner of the board thus providing some mechanical rigidity, A small diode (1N4001 etc) must be fitted between the positive battery terminal and the positive battery PCB land where the original battery was located. Because of the fragility of the positive connection on the PCB a VERY thin wire must be used to connect this point to the cathode of the diode which I mounted under the battery socket, on no account try to fit the diode directly to the PCB land as it will fail very quickly.
PCB showing the battery.
Original battery Location
Original battery removed and solder tag fitted to corner of board
Final view, the flat cable connecting the SD socket to the PCB was removed temporarily.
The circuits above show the original and modified arrangements.
Quite a bit of heat is needed to remove the original battery so great care must be taken to prevent any damage to the PCB and surrounding components.
