IC 718 HF transceiver..installation of a CW filter ..with plenty of pictures.
Not all my HF radios are oldies from the 1970s! I actually have one (almost NEW!!) IC-718. It is less than 2 years old and I bought it from an oldtimer
who decided to part with it. A cw filter came available at a good price used on one of the swap shops so I bought it. Its an FL 52A ICOM narrow CW
filter. Installation was fairly straightforward ..but for those who are hesitant about opening up the lid of a modern HF transceiver with
sophisticated and miniaturized components..I thought Id write a short article with lots of pictures to show what is involved.
The first step is to take all the screws that hold the top piece
and bottom piece of the cabinet to the chassis.
The two halves then come off with ease.
Now..the CW filter is placed just next to the fan. You have to
remove the circuit board and tilt it almost 90 degrees up in
order to access the bottom side of the circuit board.

When mounted in place on the circuit board..the CW filter then
bolts to the board with 2 nuts and there are 4 solder joints to
solder to pins on the filter.

Its pretty easy to do. The tough part (not all that tough) is
gently prying and pulling the thin connecting cables with the
multi-track conductors out of their connectors on the circuit
board. YOu have to use gentle finger pressure and rock the
thin "ribbon cable" so as to separate it from the connector on
the circuit board.

What I do..(since I am not all that gifted mechanically and I
have poor memory for mechanical stuff)..I leave little
descriptive tags on the cables as to how they are routed and
where...(as necessary). In this case with the 718..I only kept a
few notes.

For more complex assemblies ..I would draw a good clear
sketch. I did this one time..back in the 1980s..when I replaced
a fuse box for my Volkswagen Rabbit. I pulled a fusebox from a
junk yard and carefully drew a detailed sketch with colors for
the wires and connection points. It worked fine when all
hooked up. Taking time and drawing detailed sketches really

Now..its the year 2013 and I still make sketches with paper the
odd time..but as well..I take lots of close up digital pictures to
keep track of where things go.
On each side there is a transistor with a heatsink clip which holds the transistor
body to the chasis. Each of those has to be removed.

The thin ribbon cables (or whatever they are really called!) just slip into the
connectors on the circuit board and its a pressure fit.

All the connectors including the two RF cables near the back where the SO239
RF output connector is..all have to come out.
I won't go into the steps for setting up the menu for the optional filter. It is relatively easy. In fact ..the IC718 is pretty basic for a modern radio.
I am almost tempted to specialize in repairing these radios. There are plenty of them out there; judging by the number of user reports on eham.

Most people are quite pleased with the IC-718. I find it a nice basic rig. I still use my Argonaut 505s, 509 and 515..but more and more Iam turning
to use the 718 because of the CW filter and the fact that it is so sensitive on receive.

I look forward to qrp contesting with the 718 now that I have the CW filter. It should cut down on the noise as well..at least to some degree. I
have a noisy city lot installation here. -- As for qrp..the 718 dials right down to 1 watt if you like and it tells you how much power you are set up
Link to my home page..amateur radio (mainly)..www.earlandrews.com
or www.ham
electronicsmagazine.com..CLICK HERE FOR MY START
PAGE (lots of good ham radio informative articles (technically
oriented)..also..I sell parts for older solid state transceivers from the
These ribbon cable connectors (I dont know if that is the
correct name for them or not!) -- the blue ones in the
picture..are like a thin plastic card that you slip (under gentle
hand pressure); and maybe a bit of rocking motion as
well...into the white female connector on the circuit board

Not too hard to do at all! In fact..Id say this is a job (installing
the optional filter); that any average ham could do.

Actually..I did a google search for IC 718 and optional filter
installation and I downloaded and printed a full set of
instructions on both the physical task and the task of using
the IC718 set up menu to program in the new filter.

What I  really find nice about the IC718 filter vs the
FT301filter on cw..is that you can just hit a button on the
IC-718 to go to from narrow CW filter to wide setting.

With the FT301 and CW filter installed..you cannot switch to
wide filter at a push of a button. I like to switch to wide setting
to "hear the band".
The FL-52 I bought was used and I noticed there was some solder buildup on
the terminals..so I used some solder wick braid and put a bit of solder flux on
the braid with a toothpick. This facilitates the flow of solder and gets it to flow
better I find.
Above..the circuit board in the IC718 is rotated up to expose the bottom side of the board.
Now you have to bolt the CW filter in place and solder as well.

Note: left pic..a note I left myself on how to route the cable.
My index finger points to the direction of force (gentle force) that must be placed on the
circuit board to move it. NOTE: Don't do like I did and forget to remove the transistor clips on
each side..
see pic below...or you will wonder why the board doesn't want to move!!! - First you lift the
board up a wee bit then push forward and then move the board up 90 degree angle with
respect to the radio. I have some pullling tools. A tool with a 90 degree lip to tuck in under
the circuit card (or maybe an IC) to pull it up and out. Pictured below..I use a type of mini pry
tool to gently lift the heat sink clip from the radio chassis and the transistor body. There is
one on each side to be removed then re-installed after.
The fan had to be removed to allow the circuit board to move
forwards enough to be tilted upwards.