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5 Way Remote Antenna Switch

I am indebted to QST and the ARRL for publishing this article (Jan 2015 issue). As mentioned in the article (you have to get a copy yourself to take advantage of the design), I have designed a 5 way HF remote antenna switch for the antennas currently mounted in my garden. The reason for adopting this approach is that I was not happy to run another cable; coax or control cable from the shack to the mast for switching between additional antennas. The first time I did this up a ladder proved to me just how dangerous it was running in the original length of RG213. I did not fall off, but up the top of the ladder at such an angle to the house, I did not feel safe, I did remain aloft. The original job was done a while ago, and “there is no way you were getting me up that ladder again, even if you paid me!”.

 

I had no option but to run DC power, RF signal and antenna switching selection down the one coax cable.

 

I have worked on a number of these types of switching systems for the home QTH, and have had a fair amount of experience with DC power, RF and signalling running down the same piece of coax. The system works very well and I could not have done any better. I now have three antennas on the mast, and can add and switch in an additional two or more. The design lends itself to HF, however it will run at VHF frequencies; - this is not discussed in the article.

 

Loss through the whole switch including 100 foot run of RG213 is no more than 1.5dB over the HF band. The bias tees I have designed are the ones shown elsewhere on this website and should be good for 1kW. The current design with the PCB redesigned shown here has greater clearance and should be good for 400w RF.

 

I believe the ARRL will be making some of the files available to readers. But should anyone wish a small modification to any of the PIC codes I will provide it free of charge. I have five sets of PCBs for sale at a reasonable price.

 

This is all you are getting for free. The full article is in Jan 2015 issue of QST

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