IC-02AT frequency expansion
                 ===========================

For serial numbers above 34000

1.  Remove back from radio (5 screws) and bottom plate (4 screws).
2.  Carefully remove radio chassis from front case by pulling out top of
    radio and lifting slightly (to remove battery contacts from bottom case).
    Be extremely careful of ribbon cable and heat sink compound on power
    amplifier module.
3.  Remove diode D2 from matrix board.
4.  Add diode D4 (any small diode 1N4148; 1SS211).
5.  The following is a schematic of the matrix board:

 ADD D4                REMOVE D2
I--+        --+--      --+--        +
V D4        ID3 I      ID2 I       D1
I           I   I      I   I
+    +      +---+      +---+      +   +

6.  Install radio chassis back into front cover. Leave back off temporarily.
7.  Carefully apply power to radio and enter the lowest desired frequency.
8.  Adjust slug through bottom hole on VCO cover for .5 VDC at VCO test point
    (just below VCO shield) at lowest desired operating frequency.
9.  This completes the modification. A few words of caution:
    1.  The radio is not type accepted for use in the commercial band.
    2.  Make sure you reinstall the battery latch correctly on bottom of
        radio or battery will become permanently locked onto radio.
    3.  Tighten screws on bottom of radio snuggly. If they loosen while
        battery is connected you cannot remove the battery. (This has
        happened to many units and it would be prudent to periodically check
        these screws to assure their tightness.)

LTC STEVE PETERS, CAP

Alternative option
~~~~~~~~~~~~~~~~~~
The following method is offered as an alternative to the above modification.
This one should give you PL out of band without jumpering 5 VDC to the tone
chip. Use 1N914 or equivalent when adding diodes.

1.  On the logic matrix, remove D402 and D403.
2.  Add D402, D403 and D404 with the cathode at 4 o'clock and the anode at 12
    o'clock.
3.  Retune the VCO to cover your desired frequency spread.  The sample IC02AT
    did not work beyond 163MHz., although another reportedly worked into the
    low 170MHz. range.

4.  To jump from 140 to 150 or from 150 to 160 (or vice versa) you must "tune
    across" the boundary, in the same way that you do for an unmodified 02AT.
    For example, key in 149.995 and then move up until you are in the 150s.
    You can then enter any 150MHz frequency (starting with the MHz).

Be careful not to transmit out-of-band, or accidentally operate on any
non-amateur frequency, unless you are authorized to do so.

DO NOT JEOPARDIZE YOUR LICENCE!
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(Downloaded from GB7SYP)