Title       : FT-767gx UHF extended coverage

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*** MODIFY FOR EXTENDED COVERAGE IN FT 767 GX 430 MHz MODULE ***
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*************************************************By IK4MGX******
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Hi to everybody.
With this modification, you will be able to Tune your FT-767
RTX from 420 to 449 MHz all modes.
 
1) Unplug power cable and all the antenna plugs from the unit
 
2) With a screwdriver extract the two screws that fix the UHF 
   module to the rest of RTX and extract it.
   Unscrew the fourth screw of the superior cover.
 
3) Localize the TC 9122 CHIPS. They are DPLL Chips oscillators.
 
4) Depending of the two versions of this unit (A and B) you
   surely 'll notice three soldering pads between two TC 9122
   marked A and B.
   Clear the three pads from solder and connect them three wire
   (if shielded is better).
 
5) With a 3 position switch connect A and B wire to the external     
   pads and central wire to the central pads of the switch.
   
5) Now, close and reassemble the unit.
 
Now You can Receive and Transmit from 420 to 450 Mhz with 10 Mhz
segments by changig position of the switch.
 
None of wire connected (Switch in the central position):
                                                   420 - 430 MHz
Central and A wire connected:                      430 - 440 MHz
Central and B wire connected:                      440 - 450 MHz
 
*** NOT POSSIBLE WITH ONLY ONE SWITCH ***
All three wire connected:                          450 - 460 MHz
 
That's All !
It is possible add new combinations and new segments frequency
coverage by cutting one or more pin of Q11 C.I. (the medial 
TC 9122 chip) and doing all the binary combinations.
If you see the circuit, A and B connections are connected to pin
3 and pin 4 of the TC 9122,and the central is the ground.
So use pin 2 with the other to have more lower frequencies, or
use pin 5 and/or pin 6 to have more higer frequencies.
See this table for example.
 
1 Stands for OPEN (Unconnected) 
0 stands for CLOSED (connected to the ground).
 
!============================================!
! Pin !  2 !  3 !  4 !  5 !  6 ! Freq. Range !
!-----+----+----+----+----+----+-------------!
!     !  1 !  1 !  1 !  1 !  1 !  420 - 430  !
!     !  1 !  0 !  1 !  1 !  1 !  430 - 440  !
!     !  1 !  1 !  0 !  1 !  1 !  440 - 450  !
!     !  1 !  0 !  0 !  1 !  1 !  450 - 460  !
!     !  1 !  1 !  1 !  0 !  1 !  460 - 470  !
!     !  1 !  0 !  1 !  0 !  1 !  470 - 480  !
!     !  1 !  1 !  0 !  0 !  1 !  480 - 490  !
!     !  1 !  0 !  0 !  0 !  1 !  490 - 500  !
!     !  1 !  1 !  1 !  1 !  0 !  500 - 510  !
!     !  1 !  0 !  1 !  1 !  0 !  510 - 520  !
!============================================!
 
The table can continue but only for theory !
The unit is regulated with filters for a close range of Freq.
and so we can go over some frequencies... but this is different
from unit to unit... they aren't all equal !
In addittion, the PLL will doesn't lock the frequency over
a certain frequency !
If I was you, I'd use only the 3 position switch !
Now I'm working to change the frequency value on the display
to have 430-440 visualisation...
 
 
OK. That's All for the moment. I hope to receive suggestions,
crytics and comments from someone !
Sorry for my bad English but I can't do better !
 
73 and good Work from IK4MGX -Op. Davide- Italy ===>BBS: I4UJB