开云体育

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:

*
*

*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*

--

*Dave - W?LEV*


--
Dave - W?LEV