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Hi Everyone,

                  It's been a while since I have contributed to the forum.  I have been spending quite a bit of time working bugs out of my Tricopter build but have learned much in the process.  What I wanted to share with you was my revision of the "IB Crazy Cloverleaf Antenna for 5.8ghz." Here is what I did:

At these frequencies many things are critical to the correct performance of an antenna. Ghost capacities are a real problem so you have to watch what you do. Certain materials also cause resonance problems so you need to be mindful of these.  When in doubt Silver plate all conductors. It will stop a mountain of problems with SWR.  Gold is even better if you have it but that is out of the scope of most modelers bags.

What I decided is that, while I liked the IB Crazy Cloverleaf, I never have liked antennas that can flop around on the end of a coax.  I prefer a rigid mount and coax is not that.  The option exists to make your coax very short but then you are dealing with working in very small areas.  Again...not for me. So, I decided to make a rigid coax out of some RG-174 that I had on hand. Here is how I did it.

What I did was get a package of KS brand 3/32 copper tubing with a .014 wall thickness at the local hobby shop. The internal dimension of this cable is the exact outer dimension of RG-174.  I cut about a 3 inch section of this to make my antenna.

Next I took apart a screw together SMA connector and looked at the inner parts. If you look at the coax shield retainer you will see that it is built like a long tapered cone. This is important because it holds the outer shield in a bind to make up the ground.  In my case I had to solder the copper tube to this and I wanted a good, solid, joint.  What I did was to take an automatic (push type) center punch and flare the copper tube to fit this taper.  A few good snaps and it fits like a glove.  I suppose you could also turn down a piece of steel rod in a drill press and do the same thing. Then use the drill press to press the rod down into the copper.  Either way will work.  It is a good idea to polish the copper after you are done and silver plate it.

Once you have the copper tube swaged and Silver plated it is time to solder it to the SMA shield cone.  I held mine in a small vise and set the SMA cone on top. (taper fits into the taper on the Copper tube) Use some good quality flux when you do this and electronics grade solder. Once done you should have a really solid antenna base (ground).  This will be your new shield for the RG-174.

Now you want to strip out the center conductor from the RG-174.  Make it long enough to stick an inch past the end of the tube.  Make up the SMA connector like you would do for a coax assembly. Don't forget to use the Teflon insert or your antenna won't work!  I also put heat shrink on over the copper tubing once I assembled the connector.  I ran one piece of clear down to the jam nut and then put white on over the whole connector and the copper tube.  You will need to expand the shrink a little with pliers on the connector end before you slide it on. If you pick a size that just fits the connector it may not shrink enough. Most only shrinks 50%.

After all of this just make up the IB Crazy Cloverleaf as it is described in his text.  It's an easy build and if you follow the directions fairly foolproof.  Personally I would hedge away from using MIG wire as he suggests.  The Iron in the wire can and will detune things just slightly and you will get a much better match with copper or Silver Plated Brass.  (this is what I used)  It is much stiffer than Copper and resists bending out of shape.

Now...Here is my second change to the design: Go to the hobby shop and pick up some white plastic sheet. (Note: you can also use an old Clorox bottle) Cut this up into confetti and put it in a small glass jar with a lid.  Next, go to the hardware store and pick up some Methyl Ethyl Ketone and pour it over the plastic chips. (This stuff is nasty and is a Carcinogen so be careful with it.) It is advisable to do this out in the open air.  Let this mixture sit for a few hours and it will dissolve into paintable plastic. (This was used as a cement for the original Dubro Whirlybird body).

Use this mixture to paint the exposed surfaces of the antenna.  You can do this with a normal model brush as the mixture is fairly thin to apply and you will need to put on several coats.  Let the antenna dry between applications and you will have a "Factory Finish" on your antenna that will make it strong and durable for years of flying.  (See example)