[Antennas] GP's and other fine things
Henry Mei'l's
meils at get2net.dk
Wed Mar 2 12:41:38 EST 2011
Unfortunately the landlord wouldn't allow radials in the backyard and I was
lucky he let me put up the vertical on the fence.
I've played a lot with verticals both before and since. One set up was using
my metal corrugated garage roof as GP,
counterpoise and alternately using the roof itself as antenna against ground
rods. Same thing at this QTH, my steel balcony used as either a counterpoise
for whip radiators or my tuner-matching the frame itself on 160 through 20
meters. The balcony is not a great antenna but I get reasonably good reports
and I don't have any hassle about antenna restrictions. I hope the neighbors
sunning themselves on the balconies below me don't hear me on their
fillings, or have sparks jumping across their
aluminum chairs.
BTW I restrict my input to about 30-40 Watts. No need to push my luck.
Technically speaking, the balconies below mine must be interact with my
balcony at least thru capacitative coupling and
on some frequencies may be acting as reflectors, beaming my signal straight
up, giving diathermy comfort to seagulls or act as directors, sending my
signal straight down to where they don't need more heat -- or warming worms?
Henry oz3o n2nr
----- Original Message -----
From: <antennas-request at mailman.qth.net>
To: <antennas at mailman.qth.net>
Sent: Wednesday, March 02, 2011 6:02 PM
Subject: Antennas Digest, Vol 86, Issue 3
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> 1. Re: Antennas Digest, Vol 86, Issue 1 (Ron Youvan)
> 2. Re: Antennas Digest, Vol 86, Issue 1 (Michael Goins)
> 3. Re: Antennas Digest, Vol 86, Issue 1 (Ron Youvan)
> 4. Antennas digest,vol 86,lssue (Rick Gouge)
> 5. Re: Antenna SWR (David C. Hallam)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Wed, 02 Mar 2011 08:38:47 -0500
> From: Ron Youvan <ka4inm at tampabay.rr.com>
> Subject: Re: [Antennas] Antennas Digest, Vol 86, Issue 1
> To: a <antennas at mailman.qth.net>
> Message-ID: <4D6E4867.5040403 at tampabay.rr.com>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> Henry oz3o n2nr Mei'l's wrote:
>
>> I experienced that immediately after (April!) rains showers, I could
>> work
>> Florida and other Southern states on 40 meters AM from NYC, in mid
>> afternoon, running about 70 Watts -- the antenna was a 1/4 vertical using
>> a
>> wire mesh fence as ground counterpoise.
>> I could not do this in dry weather. Sunspot activity was also very
>> favorable
>> in the late 50's.
>
> Much more counterpoise (tuned as in 1/4 wl) and you can enjoy that
> performance year round and more.
>
>> Since the theoretical impedance of an ideal GP is 35 ohms, what about
>> using
>> two parallel 70 ohm
>> cables? But I suppose 50 ohms approaches the actual impedance of
>> non-ideal
>> GP's. By adjusting the angle of the radials
>> with respect to the horizontal, 50 ohms can be achieved, assuming your
>> feed
>> point height and physical environment makes this a practical
>> possibility --
>> not often the case on the lower bands.
>
> Two 75 Ohm cables (the exact same length) in parallel is perfect and
> has been used for at least 50 years. (RG-59, RG-11 or cable company wire)
> --
> Ron KA4INM - Endless Loop: n. see Loop, Endless.
> Loop, Endless: n. see Endless Loop.
> -- Random Shack Data Processing Dictionary
>
>
>
> ------------------------------
>
> Message: 2
> Date: Wed, 2 Mar 2011 07:46:27 -0600
> From: Michael Goins <wmgoins at gmail.com>
> Subject: Re: [Antennas] Antennas Digest, Vol 86, Issue 1
> Cc: antennas at mailman.qth.net
> Message-ID:
> <AANLkTik0UWVRkXSfxo3wE1EPstrfzSwz6RAeq8gML5Ka at mail.gmail.com>
> Content-Type: text/plain; charset=UTF-8
>
> I would disagree with the "been around 50 years" comment. Been a ham here
> since 1976, never owned a commercial antenna, and have studied antennas
> the
> entire time. There have been few references to double coax, and that was
> often 50 ohm where it connected with open feeders or twinlead as a
> passthrough need. The doubled 75 ohm coax concept is not "common." And
> unless the vertical is actually elevated, the radials don't need to be
> "tuned." There just needs to be as many of them as you can make work with
> your installation if ground mounted.
>
> Counterpoise gets tuned, radial don't need to be.
>
> Mike, k5wmg
> Pipe Creek, Texas
> A thousand words a day. Five days a week. For life.
>
>
> On Wed, Mar 2, 2011 at 7:38 AM, Ron Youvan <ka4inm at tampabay.rr.com> wrote:
>
>> Henry oz3o n2nr Mei'l's wrote:
>>
>> > I experienced that immediately after (April!) rains showers, I could
>> work
>> > Florida and other Southern states on 40 meters AM from NYC, in mid
>> > afternoon, running about 70 Watts -- the antenna was a 1/4 vertical
>> > using
>> a
>> > wire mesh fence as ground counterpoise.
>> > I could not do this in dry weather. Sunspot activity was also very
>> favorable
>> > in the late 50's.
>>
>> Much more counterpoise (tuned as in 1/4 wl) and you can enjoy that
>> performance year round and more.
>>
>> > Since the theoretical impedance of an ideal GP is 35 ohms, what about
>> using
>> > two parallel 70 ohm
>> > cables? But I suppose 50 ohms approaches the actual impedance of
>> non-ideal
>> > GP's. By adjusting the angle of the radials
>> > with respect to the horizontal, 50 ohms can be achieved, assuming your
>> feed
>> > point height and physical environment makes this a practical
>> > possibility
>> --
>> > not often the case on the lower bands.
>>
>> Two 75 Ohm cables (the exact same length) in parallel is perfect and
>> has been used for at least 50 years. (RG-59, RG-11 or cable company
>> wire)
>> --
>> Ron KA4INM - Endless Loop: n. see Loop, Endless.
>> Loop, Endless: n. see Endless Loop.
>> -- Random Shack Data Processing Dictionary
>>
>> ______________________________________________________________
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>
>
> ------------------------------
>
> Message: 3
> Date: Wed, 02 Mar 2011 09:24:58 -0500
> From: Ron Youvan <ka4inm at tampabay.rr.com>
> Subject: Re: [Antennas] Antennas Digest, Vol 86, Issue 1
> To: a <antennas at mailman.qth.net>
> Message-ID: <4D6E533A.9020400 at tampabay.rr.com>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> Michael Goins wrote:
>
>> I would disagree with the "been around 50 years" comment. Been a ham here
>> since 1976, never owned a commercial antenna, and have studied antennas
>> the
>> entire time. There have been few references to double coax, and that was
>> often 50 ohm where it connected with open feeders or twinlead as a
>> pass through need. The doubled 75 ohm coax concept is not "common." And
>> unless the vertical is actually elevated, the radials don't need to be
>> "tuned." There just needs to be as many of them as you can make work with
>> your installation if ground mounted.
>
> I started trying to become HAM in 1955, I hear of folks doing it.
> (became licensed in 1973)
>
>> Counterpoise gets tuned, radial don't need to be.
>
> Suit yourself, but I think being tuned is helpful, am broadcast
> radials are customarily tuned. A 1/4 wl element is not an antenna.
> --
> Ron KA4INM - Endless Loop: n. see Loop, Endless.
> Loop, Endless: n. see Endless Loop.
> -- Random Shack Data Processing Dictionary
>
>
>
> ------------------------------
>
> Message: 4
> Date: Wed, 2 Mar 2011 07:40:02 -0800
> From: "Rick Gouge" <rickgouge at shaw.ca>
> Subject: [Antennas] Antennas digest,vol 86,lssue
> To: <Antennas at mailman.qth.net>
> Message-ID: <092393A089184B7BBED175D6E5306AF8 at seanix3387bc20>
> Content-Type: text/plain; charset="iso-8859-1"
>
> Everything below the HF6V is the other half of the antenna. The feed line
> should be below the ground radials. I agree, The more medal you have in
> the ground is the way to go. Or if your in a mobile home, Use the tin roof
> as your ground plain. Rick VE7RiK
>
> ------------------------------
>
> Message: 5
> Date: Tue, 01 Mar 2011 12:55:15 -0500
> From: "David C. Hallam" <dhallam at knology.net>
> Subject: Re: [Antennas] Antenna SWR
> To: n9qzd at spbbs.com
> Cc: Antennas <antennas at mailman.qth.net>
> Message-ID: <4D6D3303.3020307 at knology.net>
> Content-Type: text/plain; charset=windows-1252; format=flowed
>
>
>
>
> First set is before and the second is after rain.
>
> David
> KW4DH
>
> On 3/1/2011 12:45 PM, N9QZD wrote:
>> Didn't say how much of a change. Could just be the wet ground under the
>> antenna. Lower ground losses would probably push your swr up.
>>
>> -
>> Sent from my BlackBerry!
>>
>> -----Original Message-----
>> From: "David C. Hallam"<dhallam at knology.net>
>> Sender: antennas-bounces at mailman.qth.net
>> Date: Tue, 01 Mar 2011 12:22:23
>> To: Antennas<antennas at mailman.qth.net>
>> Reply-To: dhallam at knology.net
>> Subject: [Antennas] Antenna SWR
>>
>> I just got a new play toy, an antenna analyzer, and have taken some SWR
>> measurements on my antenna. I have a Butternut HF6V. This morning I
>> measured the SWR. Shortly afterward we had a rain storm. Out of
>> curiosity I measured the SWR again and found a significant upward change
>> on all bands. I am confident there is no water egress at the connection
>> of the feed line to 20M 1/4 wave transformer section. All joints on the
>> antenna were assembled with Noalox. Maybe there could have been some
>> water egress at the connecting lugs of the the 1/4 section on the
>> antenna where they connect to the antenna but they appear to be sealed.
>>
>> Should I expect a SWR change just from a wet antenna?
>>
>
> --
> ?I bring reason to your ears, and, in language as plain as ABC, hold up
> truth to your eyes.? Thomas Paine, December 23, 1776
>
>
>
> ------------------------------
>
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