Subject: Double the number of memory channels in the ICOM R-7000!

  Increasing the number of memory channels in the R-7000 is fairly
easy.  The modification can be made in about an hour.  The high
order address bit (A10) of the memory chip is tied to ground.  You
need to lift that pin from ground and install a switch to toggle
this pin to ground or +5 volts.  That will give you two different
banks of memory channels.  The original bank when the switch is on
ground, and an additional bank when the switch is on +5 volts.

  Before you start the modification, write down the frequencies that
you have programmed into the unit.  During the modification you
will be unsoldering one lead of the Lithium backup battery.

  The ICOM R-7000 uses only part of the memory on it's Static Ram
chip.  You can access the the unused portion of this memory thereby
doubling the number of memory channels.

  The memory chip is IC-8 located on the Control Board.  The control
board is on the bottom of the rig under the mounting location for
the voice synthesizer and remote control boards.  It can be accessed
by removing the four philips head screws on the metal partition.

  IC-8 is under the Lithium battery.  With the rig upside down and
the back of the rig toward you, unsolder the left lead on the Lithium
battery and tilt it up out of your way.

  Remove the six mounting screws for the control unit PC board and
the three connectors along the edge of the board closest to you.
This will allow you to tilt the board up and get to bottom of the
board.  Unsolder IC-8 pin 19 (address bit A10).  Then go to the top
of the board and "gently" pull this pin through the board.  Connect
a 47k resistor from this pin to a source of +5 volts.  You can find
+5v on pin 14 of any of the 14 pin chips to the left of IC-8.


  Also from IC-8 pin 19, run a long wire to the front of the unit.
This wire will be connected to a switch that can be mounted to the
bottom cover.  Resolder the lithium battery lead that was disconnected
and reinstall the control board and the partition above it.

  Looking at the bottom cover, you will see two holes near the front.
The hole closest to the edge is used to adjust the drag on the tuning
knob.  The next hole in from the edge is the one you want.  Mount a
small SPST switch in this hole.  I used a small plug and mating
connector to make the connections between the switch and the logic
board.  The long wire that you connected to IC-8 pin 19 goes to one
side of the switch and a wire to a ground point goes to the other
switch connection.  I used one of the mounting screws that hold the
remote control board for my ground lead.

  When you have finished, you will have a second switch selectable
bank of memory channels.  This also means that you can program in
one pair of search limits for each of the two banks of memory.

Rich ( K2QG )