Re: Topband: Using shielded CAT5 data cable as feedline foractive antenna; benefits of multi-turn K9AY loop/SAL/etc?

[Tom W8JI]

Sounds like you, Tom, and LZ1AQ are saying the same: in order for loops to 
be effective (low SNR and high signal levels), they must have large area 
and low reactance (inductance to be exact). Parallel loops or fat conduits 
increase the signal levels, while the CP configuration and other similar 
measures are aimed at lowering the loop's inductance. All this of course 
is paired with a designed-for-purpose amp that does match the low loop 
impedance.


Rudy N2WQ


There are a dozen ways to say the same thing, but the physical area of a 
loop (when it is very small) determines the maximum energy extracted. This 
is why small transmitting loops are all pretty much single turn and single 
conductor.


The sensitivity and what configuration produces maximum sensitivity has a 
great deal to do with the load placed on the loop and how the loop matches 
the load. For example, if the loop has a high impedance amplifier or 
matching system terminating the loop, it might be more sensitive with the 
extra turns in series rather than parallel.


Then we have things that are called loops and look like loops, but really 
function in a different mode than a small loop. All of the small 
unidirectional loops act like pairs of small verticals that are phased. This 
includes the EWE right through the flag or pennant. They ideally have 
uniform current, which is made uniform by the terminating resistance which 
terminates the wire in its surge impedance, but the vertical or sloped ends 
are what we want to act like the antenna.


It is pretty risky to generalize across everything, but what it all boils 
down to is the multiple wires can be used to improve the matching or reduce 
the losses. Which is more effective depends on the exact antenna and the 
things we have  terminating the antenna.


I wouldn't count on a system of more series turns, more parallel turns, or a 
thicker conductor, offering improved S/N or performance without know the 
specific system, the external noise, and the internal noise. Pretty much 
everything "loop" I have played with gets into propagated noise without 
multiple wires or a thick element.


The thickest element I have used was old flexible copper waveguide from a BD 
station, I think it was maybe four  to six inches and oval. I've also used 
ribbon cable in small loops, but as a series connected group. For all of my 
directional loops, I never used more than a single turn because they all 
occupied enough area to get into external noise.


If there was any magic in this, it would have been used 40 years ago. :)

73 Tom 


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Re: Topband: W1BB stats before/after 1958 solar max

[Dave Blaschke, w5un]

It's too bad W1BB could not have lived to experience TopBand DXing in 
2008-2010


Dave, W5UN

On 1/4/2016 5:55 PM, Tim Shoppa wrote:

>From http://www.w8ji.com/160%20History/bul0263.pdf :

Number of different DX stations worked by W1BB on topband each winter:
1954/1955: 19
1955/1956: 26
1956/1957: 20
1958/1959: 4
1959/1960: 5
1960/1961: 11
1960/1962: 27

Tim N3QE
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Topband: W1BB stats before/after 1958 solar max

[Tim Shoppa]

>From http://www.w8ji.com/160%20History/bul0263.pdf :

Number of different DX stations worked by W1BB on topband each winter:
1954/1955: 19
1955/1956: 26
1956/1957: 20
1958/1959: 4
1959/1960: 5
1960/1961: 11
1960/1962: 27

Tim N3QE
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Re: Topband: Stew Beef

[James Rodenkirch]

Mark - I'm with you, sort ofI love contests, especially those with QRP 
categories AND, as a QRP afficionado, I do wish more hams would get on the air 
on Top Band just for the sake of making QSOs  I thoroughly enjoy working 
any ham on 160 CW, find out what my RST is, the other fella's power and antenna 
- that sort of general info - AND experience more about the Propagation 
Princess' vagaries.

71.5/72 de Jim Rodenkirch K9JWV


From: Topband  on behalf of 
lmlangenf...@tds.net 
Sent: Monday, January 4, 2016 10:13 AM
To: topband@contesting.com
Subject: Re: Topband: Stew Beef

Without taking a particular position on this issue, I have to wonder if any 
consideration has been given to this contest's namesake.  How, exactly, would 
Stew Perry have felt about more contests (especially in his name) on Top Band?

Personally, I have no idea.  I pose the question merely for 
reflection/discussion.

73,

Mark -- WA9ETW
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Re: Topband: Stew Beef

[lmlangenf...@tds.net]

Without taking a particular position on this issue, I have to wonder if any 
consideration has been given to this contest's namesake.  How, exactly, would 
Stew Perry have felt about more contests (especially in his name) on Top Band?

Personally, I have no idea.  I pose the question merely for 
reflection/discussion.

73,

Mark -- WA9ETW
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Re: Topband: Using shielded CAT5 data cable as feedline for active antenna; benefits of multi-turn K9AY loop/SAL/etc?

[Rudy Bakalov via Topband]

Sounds like you, Tom, and LZ1AQ are saying the same: in order for loops to be 
effective (low SNR and high signal levels), they must have large area and low 
reactance (inductance to be exact). Parallel loops or fat conduits increase the 
signal levels, while the CP configuration and other similar measures are aimed 
at lowering the loop's inductance. All this of course is paired with a 
designed-for-purpose amp that does match the low loop impedance.
 
Rudy N2WQ
  From: K9AY 
 To: Topband@contesting.com 
 Sent: Sunday, January 3, 2016 8:50 PM
 Subject: Re: Topband: Using shielded CAT5 data cable as feedline for active 
antenna; benefits of multi-turn K9AY loop/SAL/etc?
   
Pete & all:

I have done a number of experiments with multi-turn K9AY Loops and flags. I 
have only made brief mentions in print, mainly in last year's NCJ article. 
Still sorting out the most useful data from a number of observations.

In short, what W8JI says is true -- larger conductors increase the signal 
level, and parallel multiple loops do the same. The mechanism is more 
complicated than simply reducing losses, involving the interactions with the 
fields. I'm still working on that analysis. 

One piece of data is that increasing the spacing between multiple, parallel 
loops also increases signal level (gain). This is on a scale of inches to a 
couple feet, so it's not array gain. 

73, Gary
K9AY



Message: 9
Date: Sat, 2 Jan 2016 10:45:43 -0500
From: Pete Smith N4ZR 
To: topband reflector 
Subject: Topband: Using shielded CAT5 data cable as feedline for
active antenna; benefits of multi-turn K9AY loop/SAL/etc?
Message-ID: <5687f0a7.6030...@contesting.com>
Content-Type: text/plain; charset=utf-8; format=flowed

I was recently reading a web page by LZ1AQ 
.  It is full of fascinating data and 
design equations for the use of small magnetic loop antennas.  There 
were two points, in particular, that caught my layman's attention:

1.  He recommends using shielded CAT5 data cable with RJ-45 connectors 
as feedline.  The obvious advantage is having three pairs left over for 
voltage supply and control.  See 
 for more information.

2.  He cites experimental data showing that coplanar crossed loops and 
multi-turn quad loops both offer very significant improvement in the 
recovered signalcompared with a single loop.  See 
 to 
check whether I got this right. Anyway, it occurred to me to ask if 
anyone has ever tried multiturn K9AY, SAL or flag/pennant receiving 
antennas, and did you see something similar?

Any other critiques of his design would be appreciated.  The price is 
certainly right, and the construction looks good. A couple of 1-meter 
coplanar loops wouldn't be at all hard to construct.

-- 

73, Pete N4ZR
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Re: Topband: Stew Beef

[Tim Shoppa]

Gary, while I am primarily a contester, I have been surprised by the amount
of EU DX I can work on some non-contest nights. I agree with you; I have to
say my best nights on 160M are in fact non-contest nights.

Often my new 160M DXCC's have been coming not from contest nights
themselves, but from pericontest activity especially in the week before
CQWW.

Last week on a weeknight, I noted at the end of the 0300Z CWT that 160M
seemed to be pretty decent to Europe.

I called CQ on 160M that night, and proceeded to work 50 different European
stations  in the next 3+ hours. Most of those stations, I had never worked
on 160M before. That's was surprising to me as mostly-a-contester, because
even on a good contest weekend over two nights I might work 50 EU stations.

I was amazed not only at the good conditions, but that there were 50
European guys up in the middle of their night! There were only a couple
other NA stations who CQ'ed in those 3 hours. There were several other NA
stations responding to EU CQ's in those hours.

I think fundamentally... we need to get on 160M and CQ more outside of
contests!!!

In a different thread, folks talk about wanting E-mails when 160M
conditions are good. For me, a very valuable tool is to turn on the radio,
call CQ, and look at my reverse beacon reports in EU.

Tim N3QE

On Sun, Jan 3, 2016 at 4:40 PM, Gary Smith  wrote:

> For me, unless I use the amp, I get more DX on quiet nights than
> during a contest on 160. The more powerful stations always trump me
> when it comes to DX but while I'd rather make the contest DX Q, it's
> part of the game I chose to play, I could turn on the amp and I know
> if I hear them, I can work them.
>
> With that said, I get far more enjoyment out of working so many
> people on 160 during a contest than I do prowling the band, looking
> for a weak signal from a DXCC entity I haven't worked before.
>
> And thinking about it while I type this, I don't believe I have
> worked a DXCC ATNO or even a needed 160M ATNO during a contest in the
> last 5-6 years now. To that end, I'm usually listening to 160 most
> every night and I haven't worked a non-DXPedetion new one on 160 in
> maybe, the last 3 years.
>
> In summation; I agree with Tree's assessment. To me, for the very few
> nights per year with a contest on and considering the tremendous
> activity they generate; the rest of the year is not impacted by them
> and the amount of operators found on 160 on any given non-contest
> night, is minuscule in comparison.
>
> I don't see Contesting interfering with my contacts in the least, it
> only increases my log numbers...  :D
>
> 73 & HNY,
>
> Gary
> KA1J
>
>
> > Nothing beats a bit of context and perspective
> >
> > Plus, I love the increased DX  activity a contest brings.
> >
> > Bob AA6VB
>
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Re: Topband: Stew Beef

[Kris Mraz]

I, too, have to agree with Larry, K5RK. From my location in NTX in a noisy
urban area I struggle to hear any 160m DX (using an SAL-20 RX antenna).
Last week there was a thread about a "Huge NA-EU opening last night". I had
to chuckle because I heard nothing. I know there are other Texas stations
(like K5RK) that can hear a pin drop on 160 but as for me IF I can hear any DX I
have to be the only one calling. In a contest situation my chances are slim to
none of even hearing the DX much less working them because there will always
be a contest pileup.

As a point of reference I have worked 5 (five!) European station this season,
and 0 (zero!) Asian stations on 160m. (And I am up every morning 1-2
hours before
SR for Asia.)

So, to my point. If one of those 10 days of contesting corresponds to
the one day
there is an opening strong enough for me to hear/work a DX station then I will
have no chance of making a contact. I agree that a contest-free zone at the
bottom of the band is a good idea for consideration.

73,

Kris N5KM

PS, I do participate in the 160m contests but only casually for the reasons
given above.


-Original Message-
Date: Thu, 31 Dec 2015 15:48:43 -0500
From: "Joe Wilkowski" 
To: "'Larry Burke'" ,   
Subject: Re: Topband: Stew Beef
Message-ID: <001201d1440c$a3ba31c0$eb2e9540$@k8fc.com>
Content-Type: text/plain;   charset="us-ascii"

Well, since it is a public forum I have to side with Larry on this.  I am a
contester and enjoy mostly top band operating but I would have to agree that
too much of a good thing gets old quick.  It used to be that you looked
forward to the SP, but warm-ups, pre-warmups etc. seem to carry the theme
too far.
- Joe K8FC

-Original Message-
From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Larry
Burke
Sent: Wednesday, December 30, 2015 6:38 PM
To: topband@contesting.com
Subject: Re: Topband: Stew Beef

> Fortunately participation is not mandatory for those who have had enough.

Ah, but that's exactly my point. Those with a limited or no interest in this
event DO have to "participate" in it by virtue of the additional weekend of
chaos that it causes.

- Larry K5RK

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Re: Topband: Stew Beef

[Jim Brown]

On Sun,1/3/2016 11:02 AM, K4OWR wrote:
I've never noticed any amount of activity, specifically on 160, on a 
non contest weekend, that would be impacted since there typically is 
hardly any...again, specifically on 160 meters. 


There's a segment about 5 kHz wide that is quite active 7 nights a week 
with three of K1JT's digital modes -- WSPR (the one-way propagation 
monitor), JT65 and JT9, both of which are used for 2-way, weak signal 
work. The segment runs from about 1838 kHz to about 1843 kHz. On a 
typical evening, there's more JT65 and JT9 activity in that 5 kHz than 
in the rest of the band combined. Contests make a mess of that segment, 
just as they do with comparable segments in the HF bands. I occasionally 
use JT65 and JT9 when I'm not contesting. They have their uses, require 
different skills, and can be fun.


But I view contests exactly as Tree has articulated -- they tend to make 
it easier to work DX because there's much more DX on the air, and it's 
often possible to work contest expeditions on the days before and after.


73. Jim K9YC




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