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search for a hidden HF antenna
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* *How good can a RAIN GUTTER be on HF bands?* * * *Since moving to a "retirement community" last year I have been searching for a reasonably good HF antenna.* *I have tried a few 10-20 ft verticals (not well hidden) and a 140 ft long wire end-fed wire (which everyone can see).* * * *So how about a commercial aluminum (painted) rain gutter.* *I feed it with 50 ft RG8X?? into a? Palomar Engineering? 9:1? UNUN? with two counterpoises: 15 ft and 30 ft.* *I have a wide-range tuner in the shack, so now SWR issues. * *Well, it is "hidden" and it does tune up? on 160m, 40m, 30m, 17m, and 10 meters with SWR? < 2.5:1* *but that may mean it is just "lossy" (the UNUN).* * * *I'll give it a try this weekend with Fldigi, running no more than 25 watts on CW, PSK, and Olivia/Thor modes.* *I'm really curious about 160m at night - I have never operated on that band.* *Are there "watering holes" (freq) where different sound card modes hang out?* *Seems like everything is FT8 these days. * *10m should be easy, as it is both vertical and horizontal polarization. * * * *Here are ? Nano VNA??? SWR?? and ? RETURN LOSS graphs.* *I plot RETURN LOSS as a negative number to have the same shape as the SWR curve. * *I did one run from 1.8 to 8 MHz, and the other run from? 8 to 30 MHz. * *I'm excited about this new antenna.? No one can "see it".* *But how well will it work? * *de k3eui?? barry* |
Out of a major forest fire, insurance put us up in a large apartment
complex for 2 years. I chose the 3d floor - the top - for RF reasons. Of course, the apartment complex came with its manditory set of rules: Absolutely no antennas of any kind. However, being on the 3d floor, we had quite an assembly of rain gutters on the external surface of the building. The light went on...... I used the small metal railing on the miniature patio as a counterpoise. I snaked two wires through a drain hole at the bottom of the sliding door to the miniature patio. One wire connected to the coax braid and the other wire connected to the center conductor. The two wires were twisted to form a "sort'a" transmission line. Of course, the briad wire connected to the railing (after scraping a small amount of paint). The center conductor wire connected to one of the downspouts (after scraping a bit of paint). Once inside, I made an "ugly balun" by winding extra coax around a 3" diameter cardboard tubing. I vaguely remember around 15 turns of coax on the tube. From there, the coax was routed to the loft and fed an antenna "tuner". Well, it worked OK. But the RFI generated within the apartment complex was so bad, I could detect it on a crystal set using the rain gutter antenna directly connected to the crystal radio. Yes, I made a few contacts and had excellent reports, but the RFI severely compromised reception. Yes, rain gutters do work as makeshift - and "invisible" and unsuspecting - antennas. However, one morning I got the bug to attempt 75-meters with the antenna "tuner". That was a mistake. At the low power level of 20-watts, I set off the fire alarm throughout the entire complex (about 2 city blocks in area). Would I do it again? Absolutely!!! Fortunately, we no longer reside there!!! Dave - W?LEV On Fri, Apr 25, 2025 at 3:33?PM Barry K3EUI via groups.io <k3euibarry= [email protected]> wrote: *-- *Dave - W?LEV* -- Dave - W?LEV |
Re: rain gutter antenna
I also have one rain gutter antenna it's about 50 ft long and 8 ft above ground level. For one 40-meter freq i use a 1:1 balun (indoor 10-meter-long radial) plus a matching network i designed using the nanoVNA. Low power, about 5W, talking on CW across town but haven't tried any distant contacts. The same rain gutter and radial i've used on 20 meter WSPR using a 9:1 balun with no add'l matching network. I was heard worldwide on 20m WSPR, when conditions were good, but that's not a 2-way contact. Anyway i have better antennas than that, but it's fun to play with. Apartment complex, so i have an attic dipole and an invisible wire dipole on the roof (13 ft AGL) that i was allowed to have because the wires are tucked under the shingles and are almost impossible to see. Best 73 de WN1Z Orrin El vie, 25 abr 2025 a la(s) 9:00?a.m., W0LEV via groups.io (davearea51a= [email protected]) escribi¨®: Out of a major forest fire, insurance put us up in a large apartment |
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