This is a simple to do E-Z fix and makes your icom 706 run a lot cooler by about 80% :-)
Disconnect all power from the psu side of the radio:
- Buy a C.P.U fan that runs on 12 volts, you can find one for under $12 if you ain't got one around the shack. Try to find one around 2 inch but make sure it's 12 volts with black & red cables & brush-less.
- Cut off the plug at the fan end so you have 2 wires that are red and black.
Expose the plastic back on both FAN wires so 1/8th of on inch shows of bear wire and TIN the ends of each wire with solder & soldering iron.
- Install the fan wires by slipping the fan wires down the back end of the power plug at the Back End of the 706: fan Pos+, to Pwr Pos+, fan Neg, to Pwr Neg.
Simply follow the code black to black and red to red make sure they are a snug fit.
- Turn the 706 up-side-down MAKE SURE YOU leave the front/face on and HAVE THE FRONT STAND PULLED OUT. Look at the front & Notice the GRILL Air vents on the radio case near the face & mic input.
- Install the fan somewhere just behind the mic input but to the left and over this grill/vent of the mic input must line up with the mic input to right corner of the fan to the left of the mic input so the fan blows into the radio (* will explain later *) be sure not to put the fan over the face casing.
- Once you are comfortable with your dissection use super glue on the FAN. Just use a dab of glue on each corner of the fan just on the out side of the screw holes. You don't need to use ton's of the glue just a small spot one each corner.
- Hold the fan in place for 1 to 2 min until the fan is glued.
- Once the fan is stuck on. Test the fan by reconnecting the power cables to the P.S.U and make sure all power cables are on and nothing can short out.
- Switch on P.S.U , you should here the FAN whizzing around. Switch the radio on and leave it on for 10 to 20 mins, Then take notice how much cooler it is.
* * Explanation of why fan should blow into the radio and not out:
there is a fan inside the 706 that kicks in only when the radio gets to a certain temp. Also it kicks in when you key up the 706 at half the speed 800 RPM/2. This fan is also mounted so the air flow pushes the air to the back of the radio. So adding a fan that pushes cooler air into the under side of the radio won't hurt especially if you run PACKET or DIGTAL using the auto CQ because the radio will run very hot. And adding the extra fan will cool it down.
I have done this to my 706 M2G and you can do this to a 706 and it runs fine. The only problem I have is that you have to pull out the front bracket/ rest and you can't fold it back unless you find a smaller fan around 1 inch.