Josh380
Member
I have recently come to discover that the Solarcon-99 (A-99 replacement) is a DC grounded antenna. My radio guy (whose shop will go unmentioned, but is well known) seems to disagree with me and states "The A-99 is not a ground plane antenna". But if you google how to determine whether your antenna is a DC Grounded antenna (continuity on a multimeter shows a short at the antenna's coaxial connection), vs an antenna that is not DC Grounded (no short at antenna coax connection), and then use this test on the Solarcon-99, the answer is quite clearly that the antenna is, in fact, a DC grounded antenna.
Now, is it me that's confused here, or him? My understanding was that electrical grounding was different from RF grounding. He had suggested installing a coaxial air core balun near the base of the Solarcon-99. I may have made the diameter of the air core balun too small, but the SWR reading on my NanoVNA went from a 1:1.13 (1 to 1.13 to avoid confusion) to an unusable 3.0+. I am not sure yet if it was because of the small diameter of the air core balun I made, or of the design of the antenna and the air core balun concept causing a mismatch. Some argument has suggested quite vaguely that something must be "wonky with my setup, because the air core balun should work" (gee, that's helpful), while other argument has suggested that installing a coaxial air core balun with the Solarcon-99 will cause the SWR to skyrocket, BECAUSE it is a DC Grounded antenna.
What's got this argument started was all over RF coming back down the shielding to my radio (RCI 2970N2 which has an integrated amplifier so there should be no amp mismatch). This is sending RF into unwanted portions of my radio, such as the aftermarket IF Tap that was installed. This is then bleeding onto my SDR, which as some of you may know, is not a good thing. The IF Tap is specifically designed to shutdown on TX, and it is doing just that. It's obvious by the red indicator TX light on the board, and the noise floor completely dropping out (on my sdr program), when transmitting.
Not knowing that my antenna was a DC Grounded antenna, I installed a gas discharge lightning arrestor at the antenna input, then grounded that to my 8' copper ground rod via a solid copper wire. Since the discovery, I purchased a PolyPhaser IS-50UX-C0, which from what I've read, is better suited for a DC Grounded antenna, and is installed at the ground rod, rather than near the base of the antenna. The radio chassis is also grounded to that same ground rod.
I'm hoping that installing the correct lightning arrestor (the Polyphaser) will provide better static bleed off for lightning protection, as well as eliminating the issue of RF coming back down the coax. I could be completely wrong too. I'm not sure if there are different methods for eliminating RFI on a DC Grounded antenna vs a non DC Grounded antenna.
Before anyone says anything, I always double check my coax connectors for proper installation, and that there are no shorts in the line before I put it into service. I've already eliminated that possibility. Not to mention my NanoVNA will quite distinctly show a short in the line if one is present. There is none.
Now, is it me that's confused here, or him? My understanding was that electrical grounding was different from RF grounding. He had suggested installing a coaxial air core balun near the base of the Solarcon-99. I may have made the diameter of the air core balun too small, but the SWR reading on my NanoVNA went from a 1:1.13 (1 to 1.13 to avoid confusion) to an unusable 3.0+. I am not sure yet if it was because of the small diameter of the air core balun I made, or of the design of the antenna and the air core balun concept causing a mismatch. Some argument has suggested quite vaguely that something must be "wonky with my setup, because the air core balun should work" (gee, that's helpful), while other argument has suggested that installing a coaxial air core balun with the Solarcon-99 will cause the SWR to skyrocket, BECAUSE it is a DC Grounded antenna.
What's got this argument started was all over RF coming back down the shielding to my radio (RCI 2970N2 which has an integrated amplifier so there should be no amp mismatch). This is sending RF into unwanted portions of my radio, such as the aftermarket IF Tap that was installed. This is then bleeding onto my SDR, which as some of you may know, is not a good thing. The IF Tap is specifically designed to shutdown on TX, and it is doing just that. It's obvious by the red indicator TX light on the board, and the noise floor completely dropping out (on my sdr program), when transmitting.
Not knowing that my antenna was a DC Grounded antenna, I installed a gas discharge lightning arrestor at the antenna input, then grounded that to my 8' copper ground rod via a solid copper wire. Since the discovery, I purchased a PolyPhaser IS-50UX-C0, which from what I've read, is better suited for a DC Grounded antenna, and is installed at the ground rod, rather than near the base of the antenna. The radio chassis is also grounded to that same ground rod.
I'm hoping that installing the correct lightning arrestor (the Polyphaser) will provide better static bleed off for lightning protection, as well as eliminating the issue of RF coming back down the coax. I could be completely wrong too. I'm not sure if there are different methods for eliminating RFI on a DC Grounded antenna vs a non DC Grounded antenna.
Before anyone says anything, I always double check my coax connectors for proper installation, and that there are no shorts in the line before I put it into service. I've already eliminated that possibility. Not to mention my NanoVNA will quite distinctly show a short in the line if one is present. There is none.
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