Antenna location : 52.104213, 5,016324 20260512.
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Antenna location : 52.104213, 5,016324
20260512.
| In De Meern (Utrecht NL) my
MagLoop Antenna
showed tuning and VSWR problems after a very loud BANG from a very
nearby lightningstrike,Parts in the matchbox were posebily damaged due to large
induction currents in the loop.and voltages in capacitors. I already had made a spare
Matchbox. Several
people wanted to help me replacing it, but became scared after
they discovered that they must stand on a ladder.
So i had for more tha a year no antenna and kept silence. "Where is Nico? I do not hear him anymore". I moved. My back hurted and in 2025 my spine became so bad, that I could not stand free nor walk free without pain anymore. And I also needed to much help from my wife. She became overloaded. So I desided mysself that i had to move to an elderly full care facilty. In june 2025 I therefore moved to such a facility in Vleuten (Utrecht NL). My son-in-law Marc, helped by my grandson Brian removed the loop antenna from the roof. A new antenna. A new Magloop antnna here was to much in plain site. The only possibility was to install a nearly invisibe antenna.wire. Running from my appartment, starting at 3m hight in direction West.,At first to a big oaktree at 7m hight. From there cornered at 90degr. in direction South to another big oaktree at 5m height.This is in fact an "End fed" wire antenna. With a 2t :14t broadband matching transformer at the beginning. A commonmodechoke is inserted after about 8m coax cabel lenght.The total coax length between transformer an TS570-D TRX is about 13m.Csoax Velocity factor 0.68 (RG316). Ground. I mounted the transformer as high as possible near the ceiling to an ALU window frame .Then connected the transformer "Ground" to that frame. The ALU frame was mounted with a heavy steel clamp to the reinforcing steel in the concrete ceiling. I suppose thet all the ALU frames of all appartments above and aside me are interconnected with me.Thus forming a big metal screen for SW bands. A perfect "Counterpoise" for an endfed antenna. Trimming. i measured the antenna VSWR and its resonance frequencies, They proved to be about 4% to low for all bands from 40m to 10m. On the 80m band its resonance frequency was even 12% to low. As first, the long antenna wire must be trimmed for correct resonance from 40m to 10m. I found the "VSWR<1.5 bandwidths" at these frequencies surprisingly wide. After trimming the antenna, these SW bands will probably show good VSWR over the entire band range. As second, the short antenna wire must be trimmed for 80m band resonance. Its "VSWR<1.5 bandwidth" will be narrw.
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