	Wavecom Jr Transmitter VFO Modification
	Updated June 2008 with last frequency save feature

				By N0QBH
Original configuration:
Channel select is done by pulling one of four normally held high
lines low with the selector switch. The PIC detects the change and
serially sends the corresponding frequency to the SP5055 PLL IC.

Modification theory:
By removing the original PIC and adding 3 jumpers, we can bring the
I2C frequency control and +5v out to an easy to get at location on the
main pcb.

Procedure:
Disassemble Wavecom chassis and locate metal transmitter module.
Remove top metal cover to access internal parts. It's a tight fit.
Locate PIC IC shown in photo wcjrtx_mod1 and remove it.
 
Install jumpers as discribed: (see photo wcjrtx_mod2)
 
	PIC pin # 8  to PIC pin # 13  (SCL)
	PIC pin # 9  to PIC pin # 12  (SDA)
	PIC pin # 14 to PIC pin # 11  (+5v)

Remove metal RF module from main circuit board and locate the
four 10k pull up resistors shown in photo wcjrtx_mod3 and remove them.
 
Locate the channel select switch and remove it.
Now all four lines that will connect to VFO board are availible where
the switch used to be.

	Ground is on 4 pins in the center of the switch pads.
	+5 volts is now on channel #2 pads.
	SDA is now at channel #3 pads.
	SCL is now at channel #4 pads.

Verify your work with an ohmmeter before you continue.
Reassemble RF module and Wavecom in reverse order.

Testing:
With the VFO board connected turn the Wavecom JR on. The LCD display
should show 2300 Mhz. Pressing the up switch should increase the
frequency first in .25 Mhz steps, then after holding 2 seconds 
by 4 Mhz steps until it gets to 2500 Mhz. The down button should lower
the frequency in the same manner. Releasing the button should stop the
frequency from changing.

Memory Feature (new 2008)
The last frequency used for 5 seconds or more is saved in non volatile
memory and will be recalled the next time the unit is turned on.