[TowerTalk] C4XL Tuning

[Ron Stordahl [N5IN]]

I built my C4XL as best I could exactly per the directions.  Foolishly I did not check it out on the ground.  I should have!  I set it up for 7.030 MHz, but I found that it actually resonated at 7.130 when checked after installation.  At that point I was able to reach the 40 meter driver from the mast and lengthened the loading wire jumper points and was able to bring it down to 7.050.  But what happened was this:  Whereas at the original set up it had an SWR curve about what Force-12 described in the manual (actually about 100 KHz wide at 2:1 SWR points) when I lowered the driver to 7.050 the lowest SWR was 1.8:1 and went up from there.  Needless to say the bandwidth was dreadful.  I attribute this to not being able to retune the reflector.  It would be impossible to get to the reflector with the antenna mounted on the tower.  Had I been able to,  I trust if I could have gotten it tuned to about 6850 Khz all would have been well.

With time running out for antenna work I made a snap decision to pull it down, remove the 40 meter components and simply use it as a tri band beam (20/15/10) where it is perfectly adequate.  

I have saved the 40 meter part and next spring hope to put it up as a separate 2 element 40 meter beam.

I cannot really tell you what to do unfortunately, except this, you had better tune it up on the ground to your satisfaction or you will be taking it down again.  Possibly you can tilt it and get to the 40 meter reflector on the tower and retune it, but plan on it being a multi step process.

I would say this is my only complaint.  Its hard to tune.  Others who have this type of antenna have had similar tuning problems.  Once they got it tuned they have been happy.

Keep one thing in mind, this is a CW or Phone antenna for 40, not both.   Thats my opinion.

Ron N5IN






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