From: IT9NSE@IT9XGQ.ISIC.ITA.EU
To  : KENW@WW

TNX for reading this message,
there are two mods for the news transcever Kenwwod TH 28. The mods are:
1) Expand Tx/Rx Band in VHF 
2) Enable the 340/400 MHz Band.
And now the mods. Open your TH28, near the CPU, (Display Side) you can see Two little wire (Green) you must only cut it !

-=-=-=-=-=-
 

From: F6DNH@F5MSQ.FCEN.FRA.EU
To  : MODS@WW
  
TH28A Mods:
===========

LAYOUT OF COMPONENTS
====================

1) Remove the 4 screws holding the radio together.
2) With your finger in the battery bay, separate the two parts.
3) The inside of the keypad case has a copper RF shield.  Move this shield out of the way by removing the 2 screws and bending it up and away from  the PC board.  (There may be double sticky tape holding the shield to the IC.) Under the shield you will find a large IC surrounded by an array of diodes, as follows:
 
                    +-------+
                    |       |
                    |   IC  |
                    |       |
           D D D D  +-------+
           1 1 1 1
           5 4 3 2
                            W
           W       D D D D  1
           2       1 1 9 8
                   1 0
 
    (The diode numbers are read vertically.)
    W1 and W2 are two STRAPS

Note:  It  is  possible  to  see  Diodes and Straps without removing copper shield
 
CONFIGURATIONS      (X=PRESENT .=NONE ?=UNKNOW)
==============

       W1  W2  D8  D9 D10 D11 D12 D13 D14 D15
C1 :    ?   ?   X   X   X   X   X   X   .   .   American version   TH28A
C2 :    X   X   X   X   .   .   X   X   X   X   World Wide version TH28A
C3 :    ?   ?   .   X   .   X   X   X   X   .   Mods for American
C4 : .....???

MAXIMUM FREQUENCY COVERAGE
==========================

B1 :   Tx/Rx  FM  136.000 - 173.995
B2 :   Rx     FM  340.000 - 399.995
B3 :   Rx     AM  118.000 - 135.995
B4 :   Rx     FM  400.000 - 519.995

TONES AND SUB-TONES
===================

TH28E : is able to generate 1750HZ tone while pushing tone key under PTT 
TH28A : is able to generate sub-tones during transmission
The two models differ by the usage of TONE KEY (TH28E) and LAMP KEY
(TH28A), same button under PTT. Probabily a DIODE or a STRAP change the configuration.
 
BAND SWITCHING
==============
To switch between the modes, press the [F] key for one second, then
press the [LOW] key.  This will switch between B1-->B2-->B3-->B1
To get the UHF receive (B4), press the [BAND] key while in B1

OR (?) [to be verified]

By just cutting diode 9, you enable the wide band receive on UHF
(B4) and B2 by hitting F and LOW.

CAPABILITIES
============

Here are configurations and functions:

C2 : B1,B3,B4 and sub-tones
C3 : B1,B2,B3,B4 and sub-tones

ALL THOSES INFORMATIONS COMING FROM PACKET BBS WITH NO WARRANTY
===============================================================
 
+-------------------------------------+
! F6DNH Marc - QTH Blois - Loc:JN07PP !
!      Via BBS F5MSQ.FCEN.FRA.EU      !
+-------------------------------------+
 
73 and thank you!

DOWNLOADED AND REALIGNED FROM THE PACKET NETWORK BY BOB G0LBQ - N6XDI.