Here follows a brief story how to modify your ts 780 kenwood, to obtain a greaterfreqentie range only on 2 meters !!
It is possible to enlarge the freq. spectrum for your kenwood TS-780 duo bander. I know only a solution for the 2 meter band!!
There are to make two changes , one for the RX and one for the TX.
First step: the RX normal in europe is from 144.00 till 146.000, after modification it will be 144.000/148.999
Modification.
Put the ts-780 normaly on a table with the front to you. Remove the upper case
Now you see in the MIDDLE the control unit.!!
In the upper left corner on this control PCB you see connector 23, on the right hand off this connector you see an IC the 74ls01. On the top of this IC there
are so called Pull UP or in this case Pull down ferrit beads. (FB)
The first ( the most left) should be turned to the front, like the other two.!
I will try to draw it....
What you see before!!
----------------------------Tin case !
!
! * * *
! !
! fb
! !
! * * *
! ! !
! fb fb
!c! ! !
!o! * * *
!n!
!n!
! !!---------!
!2!! !
!3!! ic 74LS !
! ! !
! ! 01 !
-----------------------------------
Change to!!!... * * *
* * *
! ! !
FB FB FB
! ! !
* * *
----------------------------------
This modification you will find on your scheme page 25 control unit, IC.. 6C, lead 8 :6B lead 6 and 7C lead 8.
At the moment i just don't know any morewich lead i put to 5Volt. But the drawing should be sufficient!!
Now how to transmit on 144./148.999
its easier hihhhhi
Turn the tranceiver if your ready .
Up side down en remove the bottom case
Now you see the large IF PCB .
Search for the resistor.. R 240
This resistor should be removed and then its also possible to transmit ..!!
Better and nicer isit to search for connector 44 on the IF unit and to remove here cable nummer 3 called "ATX" thats has the same effect but much more eleganter and easier.
Take a good look at the connector and then you will understand the way to pullout that cable 3. Be carfull!!
So folks thats all ,I hope i helped somepeople out there..
If any one has more..... please drop a mesage .. to..
Change to 70cm repeaterschift... * * *
!
FB
* * *
! !
FB FB
! !
* *
|
