R7000.16
 
      DOUBLE THE MEMORY CHANNELS OF THE ICOM R7000 BY
                REPLACING THE SPEECH SWITCH
 
                   by Jean-Louis Ecochard
 
 
 
 
 
I Introduction
     This modification is based on information received both
     from  Bob  Parnass  and from Gary on the ICOM Technical
     Support line.
 
     Although simple, this modification is  rather  delicate
     to implement because it requires knowledge of unsolder-
     ing and soldering CMOS  components.  It  also  involves
     removing  the  speech  switch. This will of course void
     any ICOM warranty and the result may be a  very  expen-
     sive  paper  weight.  It is very important to note that
     some vendors of ICOM equipment offer a similar  modifi-
     cation for 50.
 
                             WARNING
 
     THIS OPERATION INVOLVES UNSOLDERING  ONE  LEAD  OF  THE
     CMOS  MEMORY CHIP. CMOS DEVICES ARE EXTREMELY SENSITIVE
     TO STATIC ELECTRICITY. USE  THE  APPROPRIATE  EQUIPMENT
     SUCH  AS  GROUND  STRAP,  GROUNDED SOLDERING IRON, ANTI
     STATIC MAT TO MAKE SURE YOU WILL NOT DAMAGE THE CHIP.
 
     THE SILK SCREEN REPRODUCTION IN THE ICOM R7000  SERVICE
     MANUAL  IS  INCORRECT,  REFER TO THE FOLLOWING DOCUMENT
     CONCERNING LOCATING THE POSITION OF THE SPEECH  SWITCH.
     CONTACT ICOM FOR MORE DETAILS.
 
 
 
Equipment:
     - anti static mat
     - ground wrist strap
     - tip grounded soldering iron
     - solder (thin)
     - set of screwdrivers
     - unsoldering pump
     - set small pliers wire cutters
 
 
Parts:
     - photocopy of the exploded view of the R7000
       from the ICOM R7000 service manual
     - remote switch ICOM part # SPUT 19167A
     - 47 K Ohms resistor
     - small insulated wire
 
 
 
                      January 18, 1991
 
CONTINUED IN R7000.17