Even a very thin wire shouldn't be left. Could easily slice a swimmer or
get tangled around wildlife.
Pete M3KXZ
On 18 Jan 2015 17:01, <topband-request@contesting.com> wrote:
>
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> Today's Topics:
>
> 1. Re: Beverage on Ice (Ron Feutz)
> 2. Compact magnetic loop (Ignacy Misztal)
> 3. Re: Compact magnetic loop (Bill Cromwell)
> 4. Re: Compact magnetic loop (Arthur Delibert)
> 5. Re: Compact magnetic loop (Tom W8JI)
> 6. 160 VERT (Don)
> 7. Beverage on Ice (Roger Parsons via Topband)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Sat, 17 Jan 2015 12:52:44 -0600
> From: "Ron Feutz" <feutz@wctc.net>
> To: "Topband" <topband@contesting.com>
> Subject: Re: Topband: Beverage on Ice
> Message-ID: <012865CEF7284F718B9CAA230E728828@OwnerPC>
> Content-Type: text/plain; format=flowed; charset="iso-8859-1";
> reply-type=original
>
> I did this about 10 years ago. I live on the Wisconsin River and it's
about
> a half-mile wide in front of the house.
>
> I laid out 1000' of #14 stranded, insulated wire. I terminated it with a
> 200 ohm resistor to a 1/4 wave wire and several short radials running
nearly
> parallel to the antenna/grounding wires. At the feed end, I used a 4/1
> homebrew transformer using one of "Tom's" binocular cores. The
transformer
> was grounded to a conventional 8' ground rod.
>
> The antenna never worked at all, as far as I could tell. There was no
> discernable, certainly not usable, directivity. Why, I don't have a clue.
> The techniques chosen were the result of all the best advice I could get
at
> the time on the topband reflector.
>
> FWIW, the river averages about 10-15 feet deep under the antenna and is
> sand/gravel/bedrock. I would love to try this again if someone can help
> with an improved design.
>
> 73,
>
> Ron KK9K
>
>
> -----Original Message-----
> From: Roger Parsons via Topband
> Sent: Friday, January 16, 2015 3:51 PM
> To: Topband
> Subject: Topband: Beverage on Ice
>
> I know that Beverages on Ground have been discussed on a number of
> occasions, but:
>
> I live on the shores of a reasonably large lake, and at this time of year
it
> will be frozen to at least 2' and possibly 4' or 5' deep. I believe that
ice
> is a pretty good insulator, so I wonder about the effectiveness of a wire
> just laid on the surface? It would be impossible to retrieve the wire in
the
> spring so it would have to be fine enameled copper. Even that may not be
> very environmentally friendly? If the wire survived the first couple of
days
> it would be frozen into the ice - it would be at risk from snow machines
> until that happened.
>
> This is just speculation from enforced idleness - I cleverly managed to
> break my leg during a foolish last check of my receive antennas before
> Christmas - so I can't even get into the shack, let alone onto the lake. I
> was not very hopeful in any event that EP6T would be workable from here,
but
> I am determined somehow to get there for K1N...
>
> 73 Roger
> VE3ZI
> _________________
> Topband Reflector Archives - http://www.contesting.com/_topband
>
>
>
>
> ------------------------------
>
> Message: 2
> Date: Sat, 17 Jan 2015 17:06:33 -0500
> From: Ignacy Misztal <no9e@arrl.net>
> To: topband@contesting.com
> Subject: Topband: Compact magnetic loop
> Message-ID:
> <CA+yG_kFJxjX09Z94ZTBcUjhKoPMHC=
0cirFGvx65b8keS5KCpA@mail.gmail.com>
> Content-Type: text/plain; charset=UTF-8
>
> I homebrewed a magnetic loop for diversity reception with Hi-Z 3 el. in
> K3. For perhaps up to 1000 miles the loop provides excellent separation
> between signals from Hi-Z. But it hears distant stations poorly, much
worse
> than TX inv L. Based on earlier reports I expected the loop to be very
good
> for DX.
>
> The loop is made from coax, is tuned and has a transformer. About 50 KHz
> 2:1 BW. A low-noise preamp does not improve S/N.
>
> Any experiences with the loop here?
>
> Ignacy, NO9E
>
>
> ------------------------------
>
> Message: 3
> Date: Sat, 17 Jan 2015 17:27:03 -0500
> From: Bill Cromwell <wrcromwell@gmail.com>
> To: topband@contesting.com
> Subject: Re: Topband: Compact magnetic loop
> Message-ID: <54BAE1B7.3070009@gmail.com>
> Content-Type: text/plain; charset=windows-1252; format=flowed
>
> Hi,
>
> That small mag-loop has a small aperture and so all of the signals
> delivered to your radio will be lower levels than from a bigger antenna
> (in terms of wavelength. A preamp should improve the signal strength but
> not improve the SNR over what you get with the loop and no preamp. The
> mag-loop reduces the noise with it's high Q and decreased bandwidth and
> those nulls contribute to reduced noise, too. I have excellent luck with
> mine but there just isn't any silver bullet. The mag loop I use on 160
> meters is four and a half feet in diameter. The receiver I use on 160 is
> easily overloaded without some attenuation so the reduced signal levels
> from the mag-loop are *ideal*.
>
> 73,
>
> Bill KU8H
>
> On 01/17/2015 05:06 PM, Ignacy Misztal wrote:
> > I homebrewed a magnetic loop for diversity reception with Hi-Z 3 el. in
> > K3. For perhaps up to 1000 miles the loop provides excellent separation
> > between signals from Hi-Z. But it hears distant stations poorly, much
worse
> > than TX inv L. Based on earlier reports I expected the loop to be very
good
> > for DX.
> >
> > The loop is made from coax, is tuned and has a transformer. About 50
KHz
> > 2:1 BW. A low-noise preamp does not improve S/N.
> >
> > Any experiences with the loop here?
> >
> > Ignacy, NO9E
> > _________________
> > Topband Reflector Archives - http://www.contesting.com/_topband
> >
>
>
>
> ------------------------------
>
> Message: 4
> Date: Sat, 17 Jan 2015 18:30:33 -0500
> From: Arthur Delibert <radio75a3@msn.com>
> To: Ignacy Misztal <no9e@arrl.net>, "topband@contesting.com"
> <topband@contesting.com>
> Subject: Re: Topband: Compact magnetic loop
> Message-ID: <BLU177-W144735CEA64A4703B281FDE44C0@phx.gbl>
> Content-Type: text/plain; charset="iso-8859-1"
>
> I've been playing with an amplified Wellbrook ALA 1530S+ loop antenna for
about 10 days now. It does a very good job on both close-in and
long-distance signals across the SW spectrum, and its ability to knock down
the local noise is a great benefit in my dense suburban location.
>
> Compared to my two pennant antennas, which have DX Engineering
amplifiers, both my ears and my display tell me that the Wellbrook signal
is a few dB lower, although the better S/N ratio often makes the signal
more readable on the Wellbrook. The difference in signal level is not
surprising, given the larger size of the pennants; in fact, the surprising
thing is that the difference isn't greater.
>
> Given my age and the continual loss of tall trees on the property, it's
clear that I'm going to need a replacement for the pennants someday that
doesn't require trees or ladder-climbing. The Wellbrook may be it.
>
> Art Delibert, KB3FJO
>
> > Date: Sat, 17 Jan 2015 17:06:33 -0500
> > From: no9e@arrl.net
> > To: topband@contesting.com
> > Subject: Topband: Compact magnetic loop
> >
> > I homebrewed a magnetic loop for diversity reception with Hi-Z 3 el. in
> > K3. For perhaps up to 1000 miles the loop provides excellent separation
> > between signals from Hi-Z. But it hears distant stations poorly, much
worse
> > than TX inv L. Based on earlier reports I expected the loop to be very
good
> > for DX.
> >
> > The loop is made from coax, is tuned and has a transformer. About 50
KHz
> > 2:1 BW. A low-noise preamp does not improve S/N.
> >
> > Any experiences with the loop here?
> >
> > Ignacy, NO9E
> > _________________
> > Topband Reflector Archives - http://www.contesting.com/_topband
>
>
> ------------------------------
>
> Message: 5
> Date: Sat, 17 Jan 2015 18:32:19 -0500
> From: "Tom W8JI" <w8ji@w8ji.com>
> To: "Bill Cromwell" <wrcromwell@gmail.com>, <topband@contesting.com>
> Subject: Re: Topband: Compact magnetic loop
> Message-ID: <91BC8F7FDFE34CFDB4E8BBA738D1CF1C@MAIN>
> Content-Type: text/plain; format=flowed; charset="iso-8859-1";
> reply-type=response
>
> Effective aperture is not size related.
> Effective aperture is exclusively tied to wavelength and gain.
>
> The only time effective aperture means anything for receiving is when
> external noise no longer significantly influences noise floor. Other than
> that, effective aperture is meaningless for S/N or hearing DX.
>
> The real issue with a small loop is it only has two very sharp nulls
through
> the axis. It all other directions, even straight up and below, it has
> response. This means the only points where it significantly discriminates
> against external noise are two points through the axis.
>
> Making it worse, many or most loops have terrible feedpoint designs. I
> measured a very popular expensive loop, and the pattern had considerable
> skewing because of feedline common mode response. While I had the loop
> thousands of feet from noise sources, the pattern told me the feedline
was a
> major part of the "antenna".
>
> That same antenna, near my house, was nearly dominated by conducted noise
> along the feedline. I determined the common mode "noise" sensitivity was
> only down 5-10 dB from the loop pickup when a 50 foot feedline was used.
>
> It could only be three things:
>
> 1.) The feedpoint or loop design was poor, resulting in local conducted
> noise dominating the background
>
> 2.) An inherent lack of directivity that comes with the wide peak response
> and narrow axis nulls of the loop
>
> 3.) The loop efficiency is too low for the noise floor of the preamps, and
> internal noise is limiting weak signal response (even a 3 foot loop has
> enough theoretical gain for use in a reasonably quiet location)
>
> All of those are reasonably easy to test.
>
> 73 Tom
>
>
>
>
> ----- Original Message -----
> From: "Bill Cromwell" <wrcromwell@gmail.com>
> To: <topband@contesting.com>
> Sent: Saturday, January 17, 2015 5:27 PM
> Subject: Re: Topband: Compact magnetic loop
>
>
> > Hi,
> >
> > That small mag-loop has a small aperture and so all of the signals
> > delivered to your radio will be lower levels than from a bigger antenna
> > (in terms of wavelength. A preamp should improve the signal strength but
> > not improve the SNR over what you get with the loop and no preamp. The
> > mag-loop reduces the noise with it's high Q and decreased bandwidth and
> > those nulls contribute to reduced noise, too. I have excellent luck with
> > mine but there just isn't any silver bullet. The mag loop I use on 160
> > meters is four and a half feet in diameter. The receiver I use on 160 is
> > easily overloaded without some attenuation so the reduced signal levels
> > from the mag-loop are *ideal*.
> >
> > 73,
> >
> > Bill KU8H
> >
> > On 01/17/2015 05:06 PM, Ignacy Misztal wrote:
> >> I homebrewed a magnetic loop for diversity reception with Hi-Z 3 el. in
> >> K3. For perhaps up to 1000 miles the loop provides excellent
separation
> >> between signals from Hi-Z. But it hears distant stations poorly, much
> >> worse
> >> than TX inv L. Based on earlier reports I expected the loop to be very
> >> good
> >> for DX.
> >>
> >> The loop is made from coax, is tuned and has a transformer. About 50
KHz
> >> 2:1 BW. A low-noise preamp does not improve S/N.
> >>
> >> Any experiences with the loop here?
> >>
> >> Ignacy, NO9E
> >> _________________
> >> Topband Reflector Archives - http://www.contesting.com/_topband
> >>
> >
> > _________________
> > Topband Reflector Archives - http://www.contesting.com/_topband
> >
> >
> > -----
> > No virus found in this message.
> > Checked by AVG - www.avg.com
> > Version: 2014.0.4800 / Virus Database: 4257/8945 - Release Date:
01/17/15
> >
>
>
>
> ------------------------------
>
> Message: 6
> Date: Sat, 17 Jan 2015 20:49:57 -0500
> From: "Don" <w4dee@truvista.net>
> To: <topband@contesting.com>
> Subject: Topband: 160 VERT
> Message-ID: <4E51229DF1534843B607936FD9304406@DonPC>
> Content-Type: text/plain; charset="UTF-8"
>
> I put up on of K6MM?s helically Wound 160 vert can not get SWR down
> I put up k6mm Helically wound vert for 160 but can not get SWR below 3:1
I have 8 - 1/4 wave radials of 16 awg wire out . Any suggestions you can
offer would be appreciated
>
> W4DEE
>
> ------------------------------
>
> Message: 7
> Date: Sun, 18 Jan 2015 15:02:49 +0000 (UTC)
> From: Roger Parsons via Topband <topband@contesting.com>
> To: Topband <topband@contesting.com>
> Subject: Topband: Beverage on Ice
> Message-ID:
> <
818909102.2891473.1421593369343.JavaMail.yahoo@jws106124.mail.bf1.yahoo.com>
>
> Content-Type: text/plain; charset=UTF-8
>
> Many thanks for the comments received on this reflector and privately. A
few points:
> I don't think that the proposed antenna is just another BOG - there is a
large non-conductive layer of ice before there is anything conductive.
However, here on the Canadian Shield normal ground is not very conductive
either.
>
> It would be essential to build the antenna from a very thin wire for
environmental reasons. A thicker wire could cause all sorts of problems
when the ice melts in the spring.
> There is not that much snow machine activity on this lake - I would be
unlucky for the wire to be broken, particularly if I installed it on a
Monday - it would be well frozen into the ice long before the next weekend.
> Perhaps the most interesting observation was from KK9K - what Ron did was
pretty close to my intentions. Hopefully I will be able to corroberate or
otherwise next season.
> 73 RogerVE3ZI
>
>
>
> ------------------------------
>
> Subject: Digest Footer
>
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> ------------------------------
>
> End of Topband Digest, Vol 145, Issue 18
> ****************************************
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