I had been noticing weirdnesses in my HF SWR readings recently. I run a TS-590SG to a Mosley TA-63N/TA-40-KR (40-6m). The feedline from the radio to the tower was about 250 feet of RG-8. (More on this later). At any rate, I had been noticing that sometimes the SWR was just fine and other times it was off the scale. So, today, I did some sleuthing. On the side of my house where my feedlines exit and begin the underground trip out to the tower, I opened the box and pulled the cables out to inspect them. Nothing was noted. Then, I lowered the antenna and checked all the connections. While doing that, I replace the 50 feet of RG-8 going up the tower with LMR-400.
Then, back at the rig, I fired it up for the smoke test and had infinite SWR. Now that was really weird! I pulled the cable from the back of the rig and checked for continuity and discovered a dead DC short. My antenna should not show a DC short. Back out to where the cables exited the house and I disconnected all the connections. What did I discover? One bad PL-259 that when I moved it shorted out. So, I replaced that and voila, no more short. Then, back at the rig, I did an SWR check on all 7 bands (40, 20, 17, 15, 12, 10, and 6) and found them all less than 1.5:1. Better than I had ever seen before. *So, a single bad PL-259 had been silently haunting my feedline for quite some time.* Now, I have plans for the 150 feet of RG-8 that heads out to the tower. I have 150 feet of 1/2 inch superflex hardline ready to go that will become the new feedline to the Mosely once I get the new connectors and figure out how to install them. (Does anyone have the tool for that?) The existing RG-8 will become the feedline for the new 80/160m inverted vee and 30m inverted vee. The Mosely will be on antenna 1 and the vees on antenna 2. I will put a remote tuner on the vees as well as a remote antenna switch. I also think I will install a 15 ft square receive only "Loop on Ground" as a receive antenna to help out on the low bands. Lots of good antenna work to keep this barefoot station on the air. Some head scratching, but things finally worked out. BTW, I have discovered that AI, particularly Google's Gemini, has been helpful in antenna and feedline analysis. Like always, don't take what it says for gospel, but it can lead to some really helpful insights. Hope you all have a Happy and fruitful New Year with lots of good DX. 73 es GL, Don AD0K
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