Re: Topband: Small Loop does not receive weak signal on 160m BOUVET RX SPOILER

[Wes]

Hi Tim.

I wasn't necessarily in the market for one.  It is an option but I was just 
commenting on the situation.


But thanks for you interest.

Wes  N7WS

On 12/27/2022 4:14 PM, Tim Duffy wrote:

Hello Wes

Let my team check on when this will come back. Manufacturing of HI-Z is coming 
on line at DXE soon.

We will get back to you

73
Tim K3LR
CEO DX Engineering

-Original Message-
From: Topband [mailto:topband-bounces+k3lr=k3lr@contesting.com] On Behalf 
Of Wes
Sent: Tuesday, December 27, 2022 5:05 PM
To: topband@contesting.com
Subject: Re: Topband: Small Loop does not receive weak signal on 160m BOUVET RX 
SPOILER

Except you can't buy them now.  From DXE website:

Not Available At This Time

This product cannot be ordered at this time. Future availability is unknown. We
apologize for the inconvenience

Wes  N7WS



On 12/24/2022 6:25 PM, David Raymond wrote:

There's no need for a lot of real estate to get good RX performance.  The Hi-Z
three element and four element phased vertical arrays have a small footprint
and yield a worthwhile and useful RDF.  The vertical elements are essentially
ground independent, can be made of almost anything, and can be any reasonable
length (obviously shorter elements have less capture area).  I have no
fiduciary interest in Hi-Z or DXE but am a very satisfied, long term user of
the Hi-Z-300 eight circle array.

73. . . Dave, W0FLS

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Re: Topband: Small Loop does not receive weak signal on 160m BOUVET RX SPOILER

[Tim Duffy]

Hello Wes

Let my team check on when this will come back. Manufacturing of HI-Z is coming 
on line at DXE soon.

We will get back to you

73
Tim K3LR
CEO DX Engineering

-Original Message-
From: Topband [mailto:topband-bounces+k3lr=k3lr@contesting.com] On Behalf 
Of Wes
Sent: Tuesday, December 27, 2022 5:05 PM
To: topband@contesting.com
Subject: Re: Topband: Small Loop does not receive weak signal on 160m BOUVET RX 
SPOILER

Except you can't buy them now.  From DXE website:

Not Available At This Time

This product cannot be ordered at this time. Future availability is unknown. We 
apologize for the inconvenience

Wes  N7WS



On 12/24/2022 6:25 PM, David Raymond wrote:
> There's no need for a lot of real estate to get good RX performance.  The 
> Hi-Z 
> three element and four element phased vertical arrays have a small footprint 
> and yield a worthwhile and useful RDF.  The vertical elements are essentially 
> ground independent, can be made of almost anything, and can be any reasonable 
> length (obviously shorter elements have less capture area).  I have no 
> fiduciary interest in Hi-Z or DXE but am a very satisfied, long term user of 
> the Hi-Z-300 eight circle array.
>
> 73. . . Dave, W0FLS
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Re: Topband: Small Loop does not receive weak signal on 160m BOUVET RX SPOILER

[Wes]

Except you can't buy them now.  From DXE website:

Not Available At This Time

This product cannot be ordered at this time. Future availability is unknown. We 
apologize for the inconvenience


Wes  N7WS



On 12/24/2022 6:25 PM, David Raymond wrote:
There's no need for a lot of real estate to get good RX performance.  The Hi-Z 
three element and four element phased vertical arrays have a small footprint 
and yield a worthwhile and useful RDF.  The vertical elements are essentially 
ground independent, can be made of almost anything, and can be any reasonable 
length (obviously shorter elements have less capture area).  I have no 
fiduciary interest in Hi-Z or DXE but am a very satisfied, long term user of 
the Hi-Z-300 eight circle array.


73. . . Dave, W0FLS

_
Searchable Archives: http://www.contesting.com/_topband - Topband Reflector

Re: Topband: Small Loop does not receive weak signal on 160m BOUVET RX SPOILER

[Michael Tope]

I had an interesting experience along these lines back in 2006 for the 
CQ WW 160 CW contest. Following the lead of K6SE and others, I got 
permission from the Bureau of Land Management to operate from the salt 
evaporation ponds on Koehn dry-lake near Mojave, California. I spent all 
day Thursday setting up the transmit antenna and when I started 
listening Thursday night my heart sank. The static crashes were 20 over 
S-9 and it was difficult to hear much of anything. I was worried that 
the weekend might be a bust. I had the parts with me for my home-brew RX 
4-square, but it wasn't installation friendly and there was way too much 
to do on Friday morning to have any hope of getting it up and installed 
in time for the start of the contest. Fortunately, as it turned out, 160 
was a completely different band the next two nights. All of the static 
crashes were gone and the band was amazing just listening on the TX 
antenna. I worked over 100 Asian stations that weekend (mostly JAs). So 
yeah, using the transmit-antenna for receive at a location with low 
ambient ground-wave noise can work, but as George aptly points out it's 
a crap-shoot.


73, Mike W4EF.

On 12/25/2022 7:36 AM, GEORGE WALLNER wrote:
In my experience, a DXpedition does not need an RX antenna on 160 for 
the first two to three days. During that time they are working the big 
guns with strong signals. The RX antenna is needed to give the weaker 
stations a chance once the big guns are out of the way.
In case of Bouvet, most of the signals will be coming from the NE or 
NW direction. Their "back" will be towards Antarctica, which is not a 
major source of noise. The F/B of an RX antenna will contribute little 
(but not zero).


The bigger problem will be that Bouvet Island is in the southern 
hemisphere, where it is summer this time of the year. Late-afternoon 
or evening thunderstorms taking place south of the Equator will 
generate a lot of noise (think of Africa, Amazon). Most of that noise 
will be coming from the same direction as the the NA and EU signals, 
in which case an RX antenna may not help (much). Their biggest 
challenge will be working the Far East (JA especially). That is where 
a good RX antenna, pointed in the right direction, could help because 
most of the noise would be coming from its side. With marginal TB 
QSO-s even a fraction of a dB in S/N can make the difference . Also, 
they wont have much darkness to work with. It will be tough. I would 
make the loop bigger to improve the S/N ratio and improve the JA-s' 
chances.

73,
George,
AA7JV/C6AGU
On Fri, 23 Dec 2022 23:03:36 -0600  wrote:

I was one of the 160m ops at "nearby" FT5XO.  I can tell you that when
the
WX was good the TX antennas worked very well for receiving. When the
WX turned bad, such as during the snow storm we worked through, the 160m
TX antennas
were very noisyjust as noisy as those anywhere on the planet.

Don't get me started about those awful 160m fishing buoy transmitters!!

73,
Charlie, N0TT

On Fri, 23 Dec 2022 19:45:28 -0700 Wes  writes:

All interesting.  But let me ask (and standby for flames) what is 
wrong with them simply listening on the TX antenna?
I know, I know, conventional wisdom says that you can't possibly 
work 160 DX without a separate RX antenna.  I'll confess that I am a 
little pistol and will never be on the TB Honor Roll, but I got on 
the band just to add another DXCC band to my collection (now nine). 
 I'm now at 144 confirmed, running just 500W and a 55' inverted-L on 
both TX and RX. Generally speaking I hear better that I get out.
Looking at my chances of working 3Y the optimum time is their 
sunrise (~3:30Z) when I am in complete darkness and straight across 
the terminator. They will have the sunlit ocean to their rear and 
the S. American landmass toward me.  Maybe someone can enlighten me, 
but I fail to see how a directional antenna will improve the SNR of 
my signal at their end.

Wes  N7WS

On 12/23/2022 6:46 PM, JC wrote:> Hi topband lovers>>   >> Some 
friends contact me with deep concerns about the next Bouvet DX 
expedition receiver antenna called SALAD>>   >> 

<
http://www.lz1aq.signacor.com/docs/active-wideband-directional-antenna.p
hp>
Salad antenna>>   >> I understand the concerns, Bouvet on 160m is a 
lifetime opportunity for most top-banders!>>   >> When Doug NX4D, me 
N4IS and Dr Dallas started to try to understand the limitation of 
the new Waller Flag, the first big question was;>>   >> How small a 
loop antenna can be to receive weak signal on 160, or MW?>>   >> Dr. 
Dallas Lankford III (SK), measured the internal noise of a small 
loop. 15x15 FT on his quiet QTH, and wrote a paper with the 
derivation necessary to calculate the thermal noise of a small loop. 
The study most important point was:>> >> The sensitivity of small 
loop antennas can be limited by internally generated thermal noise 
which is a characteristic of the loop itself. Even amplifying the 
loop output with the 

Re: Topband: Small Loop does not receive weak signal on 160m BOUVET RX SPOILER

[Wes]

Thanks for this George.

When I posted earlier I said: "Looking at my chances of working 3Y the optimum 
time is their sunrise (~3:30Z) when I am in complete darkness and straight 
across the terminator. They will have the sunlit ocean to their rear and the S. 
American landmass toward me.  Maybe someone can enlighten me, but I fail to see 
how a directional antenna will improve the SNR of my signal at their end. "


What George says is the point I was less eloquently trying to make.  Of course 
this doesn't account for local conditions, rain and snow static, etc.


Wes  N7WS


On 12/25/2022 8:36 AM, GEORGE WALLNER wrote:
In my experience, a DXpedition does not need an RX antenna on 160 for the 
first two to three days. During that time they are working the big guns with 
strong signals. The RX antenna is needed to give the weaker stations a chance 
once the big guns are out of the way.
In case of Bouvet, most of the signals will be coming from the NE or NW 
direction. Their "back" will be towards Antarctica, which is not a major 
source of noise. The F/B of an RX antenna will contribute little (but not zero).


The bigger problem will be that Bouvet Island is in the southern hemisphere, 
where it is summer this time of the year. Late-afternoon or evening 
thunderstorms taking place south of the Equator will generate a lot of noise 
(think of Africa, Amazon). Most of that noise will be coming from the same 
direction as the the NA and EU signals, in which case an RX antenna may not 
help (much). Their biggest challenge will be working the Far East (JA 
especially). That is where a good RX antenna, pointed in the right direction, 
could help because most of the noise would be coming from its side. With 
marginal TB QSO-s even a fraction of a dB in S/N can make the difference . 
Also, they wont have much darkness to work with. It will be tough. I would 
make the loop bigger to improve the S/N ratio and improve the JA-s' chances.

73,
George,
AA7JV/C6AGU


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Re: Topband: Small Loop does not receive weak signal on 160m BOUVET RX SPOILER

[GEORGE WALLNER]

In my experience, a DXpedition does not need an RX antenna on 160 for the 
first two to three days. During that time they are working the big guns with 
strong signals. The RX antenna is needed to give the weaker stations a 
chance once the big guns are out of the way.
In case of Bouvet, most of the signals will be coming from the NE or NW 
direction. Their "back" will be towards Antarctica, which is not a major 
source of noise. The F/B of an RX antenna will contribute little (but not 
zero).


The bigger problem will be that Bouvet Island is in the southern hemisphere, 
where it is summer this time of the year. Late-afternoon or evening 
thunderstorms taking place south of the Equator will generate a lot of noise 
(think of Africa, Amazon). Most of that noise will be coming from the same 
direction as the the NA and EU signals, in which case an RX antenna may not 
help (much). Their biggest challenge will be working the Far East (JA 
especially). That is where a good RX antenna, pointed in the right 
direction, could help because most of the noise would be coming from its 
side. With marginal TB QSO-s even a fraction of a dB in S/N can make the 
difference . Also, they wont have much darkness to work with. It will be 
tough. I would make the loop bigger to improve the S/N ratio and improve the 
JA-s' chances.

73,
George,
AA7JV/C6AGU
On Fri, 23 Dec 2022 23:03:36 -0600  wrote:

I was one of the 160m ops at "nearby" FT5XO.  I can tell you that when
the
WX was good the TX antennas worked very well for receiving.  When the
WX turned bad, such as during the snow storm we worked through, the 160m
TX antennas
were very noisyjust as noisy as those anywhere on the planet.

Don't get me started about those awful 160m fishing buoy transmitters!!

73,
Charlie, N0TT

On Fri, 23 Dec 2022 19:45:28 -0700 Wes  writes:


All interesting.  But let me ask (and standby for flames) what is wrong with 
them simply listening on the TX antenna?
I know, I know, conventional wisdom says that you can't possibly work 160 DX 
without a separate RX antenna.  I'll confess that I am a little pistol and will 
never be on the TB Honor Roll, but I got on the band just to add another DXCC 
band to my collection (now nine).  I'm now at 144 confirmed, running just 500W 
and a 55' inverted-L on both TX and RX. Generally speaking I hear better that I 
get out.
Looking at my chances of working 3Y the optimum time is their sunrise (~3:30Z) 
when I am in complete darkness and straight across the terminator. They will 
have the sunlit ocean to their rear and the S. American landmass toward me.  
Maybe someone can enlighten me, but I fail to see how a directional antenna 
will improve the SNR of my signal at their end.
Wes  N7WS

On 12/23/2022 6:46 PM, JC wrote:> Hi topband lovers>>   >> Some friends contact me with deep concerns about the next Bouvet DX expedition receiver antenna called SALAD>>   >>   

<
http://www.lz1aq.signacor.com/docs/active-wideband-directional-antenna.p
hp> 

Salad antenna>>   >> I understand the concerns, Bouvet on 160m is a lifetime opportunity for most top-banders!>>   >> When Doug 
NX4D, me N4IS and Dr Dallas started to try to understand the limitation of the new Waller Flag, the first big question was;>>   >> How 
small a loop antenna can be to receive weak signal on 160, or MW?>>   >> Dr. Dallas Lankford III (SK), measured the internal noise of a 
small loop. 15x15 FT on his quiet QTH, and wrote a paper with the derivation necessary to calculate the thermal noise of a small loop. The study most 
important point was:>>   >> The sensitivity of small loop antennas can be limited by internally generated thermal noise which is a 
characteristic of the loop itself. Even amplifying the loop output with the lowest noise figure preamp available may not improve the loop sensitivity 
if manmade noise drops low enough>>   >> The noise on Bouvet
island will be very low, < -120 dBm at 500Hz,  and for sure the internal 
thermal noise of the prosed RX antenna will limit the reception of weak 
signals on 160m, it may work on 80 and above, but for 160 m, it will be a 
set up for failure.>>   >> Why not a single, trustable beverage antenna over 
the ice or snow?? Or a proved K9AY or a DHDL??>>   >> Below is the almost 
good transcript of the original pdf Flag Theory, for the long answer.>>   >> 
  >> 73?s>> JC>> N4IS>>   >> Flag Theory> Dallas Lankford, 1/31/09, rev. 
9/9/09>>> The derivation which follows is a variation of Belrose's classical 
derivation for ferrite rod loop antennas,> ?Ferromagnetic Loop Aerials,? 
Wireless Engineer, February 1955, 41? 46.>>> Some people who have not 
actually compared the signal output of a flag antenna to other small 
antennas have expressed their opinions to me that the signal output of a 
flag antenna has
great attenuation compared to those other small antennas, such as loops and 
passive verticals. Their opinions are wrong. One should never express 
opinions which are based, say, on computer 

Re: Topband: Small Loop does not receive weak signal on 160m BOUVET RX SPOILER

[David Raymond]

There's no need for a lot of real estate to get good RX performance.  
The Hi-Z three element and four element phased vertical arrays have a 
small footprint and yield a worthwhile and useful RDF.  The vertical 
elements are essentially ground independent, can be made of almost 
anything, and can be any reasonable length (obviously shorter elements 
have less capture area).  I have no fiduciary interest in Hi-Z or DXE 
but am a very satisfied, long term user of the Hi-Z-300 eight circle array.


73. . . Dave, W0FLS

On 12/24/2022 3:18 PM, Wes wrote:
With all due respect there is an awful lot of presumption here.  Not 
everyone has the space for one or more Beverage antennas.  I have 1 
3/4 acre but the way my vertical, HF tower, house, neighbors' houses, 
etc are sited there isn't room for an array of Beverage antennas.


Wes  N7WS


On 12/24/2022 12:38 PM, Mike Waters wrote:

Yes, the advantages of having good Beverage antennas in addition to an
inverted-L are very well established indeed. I (and thousands of other
Topbanders) can vouch for that from personal experience.

Yes, there are times when your inverted-L will out-hear good Beverages.
Even DX, *but that is the exception rather than the rule.*

The information I wrote below will tell you nearly everything you 
need to

know about building effective Beverage antennas:

https://web.archive.org/web/20181115070846/http://www.w0btu.com/Beverage_antennas.html 



The biggest mistake people make is not installing their Beverages in the
correct orientation to the DX. See the information near the bottom of my
old webpage there about that.

73 Mike
W0BTU

On Sat, Dec 24, 2022, 8:38 AM Wes  wrote:

Rune has kindly spoken up, making some of this discussion moot but I 
will

continue anyway.

...

I may speak more about RX antennas in another message.

Wes  N7WS



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Re: Topband: Small Loop does not receive weak signal on 160m BOUVET RX SPOILER

[Jim Brown]

Yep. I have 8.5 acres, and it was tricky finding suitable locations for 
a pair of full-wave reversible 160M Beverages oriented to EU/VK and 
SA/JA. Feedpoints and terminations of both are at limits of my property, 
and the EU/VK Beverage terminates on my neighbor's property, installed 
there 15 years ago, long before he bought it.


73, Jim K9YC

 On 12/24/2022 1:18 PM, Wes wrote:
With all due respect there is an awful lot of presumption here.  Not 
everyone has the space for one or more Beverage antennas.  I have 1 3/4 
acre but the way my vertical, HF tower, house, neighbors' houses, etc 
are sited there isn't room for an array of Beverage antennas.


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Re: Topband: Small Loop does not receive weak signal on 160m BOUVET RX SPOILER

[Wes]

With all due respect there is an awful lot of presumption here.  Not everyone 
has the space for one or more Beverage antennas.  I have 1 3/4 acre but the way 
my vertical, HF tower, house, neighbors' houses, etc are sited there isn't room 
for an array of Beverage antennas.


Wes  N7WS


On 12/24/2022 12:38 PM, Mike Waters wrote:

Yes, the advantages of having good Beverage antennas in addition to an
inverted-L are very well established indeed. I (and thousands of other
Topbanders) can vouch for that from personal experience.

Yes, there are times when your inverted-L will out-hear good Beverages.
Even DX, *but that is the exception rather than the rule.*

The information I wrote below will tell you nearly everything you need to
know about building effective Beverage antennas:

https://web.archive.org/web/20181115070846/http://www.w0btu.com/Beverage_antennas.html

The biggest mistake people make is not installing their Beverages in the
correct orientation to the DX. See the information near the bottom of my
old webpage there about that.

73 Mike
W0BTU

On Sat, Dec 24, 2022, 8:38 AM Wes  wrote:


Rune has kindly spoken up, making some of this discussion moot but I will
continue anyway.

...

I may speak more about RX antennas in another message.

Wes  N7WS



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Re: Topband: Small Loop does not receive weak signal on 160m BOUVET RX SPOILER

[Mike Waters]

All,

Kindly direct questions to this group, and not to me privately. TIA.

73 Mike
W0BTU

On Sat, Dec 24, 2022, 1:49 PM Mike Waters  wrote:

> Oops! DON'T use an RF choke for a single-wire Beverage. Just the OY 470
> ohm resistor to a good RF ground. Sorry.
>
> 73 Mike
> W0BTU
>
> On Sat, Dec 24, 2022, 1:44 PM Mike Waters  wrote:
>
>> You need to drain off the snow static etc. with a resistor in series with
>> a proper RF choke. The values are on this page. And buy the Ohmite resistor
>> specified! :-)
>>
>>
>> https://web.archive.org/web/20181115070846/http://www.w0btu.com/Beverage_antennas.html
>>
>> On Sat, Dec 24, 2022, 12:34 PM Wes  wrote:
>>
>>> Did you have RX antennas that allowed you to work through the snow
>>> storms?  Here
>>> in AZ we can draw an ac in a PL259 in a dust storm.
>>>
>>> Wes  N7WS
>>>
>>
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Re: Topband: Small Loop does not receive weak signal on 160m BOUVET RX SPOILER

[Mike Waters]

Oops! DON'T use an RF choke for a single-wire Beverage. Just the OY 470 ohm
resistor to a good RF ground. Sorry.

73 Mike
W0BTU

On Sat, Dec 24, 2022, 1:44 PM Mike Waters  wrote:

> You need to drain off the snow static etc. with a resistor in series with
> a proper RF choke. The values are on this page. And buy the Ohmite resistor
> specified! :-)
>
>
> https://web.archive.org/web/20181115070846/http://www.w0btu.com/Beverage_antennas.html
>
> On Sat, Dec 24, 2022, 12:34 PM Wes  wrote:
>
>> Did you have RX antennas that allowed you to work through the snow
>> storms?  Here
>> in AZ we can draw an ac in a PL259 in a dust storm.
>>
>> Wes  N7WS
>>
>
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Re: Topband: Small Loop does not receive weak signal on 160m BOUVET RX SPOILER

[Mike Waters]

You need to drain off the snow static etc. with a resistor in series with a
proper RF choke. The values are on this page. And buy the Ohmite resistor
specified! :-)

https://web.archive.org/web/20181115070846/http://www.w0btu.com/Beverage_antennas.html

On Sat, Dec 24, 2022, 12:34 PM Wes  wrote:

> Did you have RX antennas that allowed you to work through the snow
> storms?  Here
> in AZ we can draw an ac in a PL259 in a dust storm.
>
> Wes  N7WS
>
_
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Re: Topband: Small Loop does not receive weak signal on 160m BOUVET RX SPOILER

[Mike Waters]

Yes, the advantages of having good Beverage antennas in addition to an
inverted-L are very well established indeed. I (and thousands of other
Topbanders) can vouch for that from personal experience.

Yes, there are times when your inverted-L will out-hear good Beverages.
Even DX, *but that is the exception rather than the rule.*

The information I wrote below will tell you nearly everything you need to
know about building effective Beverage antennas:

https://web.archive.org/web/20181115070846/http://www.w0btu.com/Beverage_antennas.html

The biggest mistake people make is not installing their Beverages in the
correct orientation to the DX. See the information near the bottom of my
old webpage there about that.

73 Mike
W0BTU

On Sat, Dec 24, 2022, 8:38 AM Wes  wrote:

> Rune has kindly spoken up, making some of this discussion moot but I will
> continue anyway.
>
> ...
>
> I may speak more about RX antennas in another message.
>
> Wes  N7WS
>
>
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Re: Topband: Small Loop does not receive weak signal on 160m BOUVET RX SPOILER

[Wes]

Thanks Charlie for the insight.  I just rewatched the video of your expedition.  
Very cool, no pun intended.   Sorry I wasn't a topband guy back then. Just 
worked you guys on 20 CW and SSB.  I worked FB8XV in 1979, also on 20 SSB.


Did you have RX antennas that allowed you to work through the snow storms?  Here 
in AZ we can draw an ac in a PL259 in a dust storm.


Wes  N7WS

On 12/23/2022 10:03 PM, n0...@juno.com wrote:

I was one of the 160m ops at "nearby" FT5XO.  I can tell you that when
the
WX was good the TX antennas worked very well for receiving.  When the
WX turned bad, such as during the snow storm we worked through, the 160m
TX antennas
were very noisyjust as noisy as those anywhere on the planet.

Don't get me started about those awful 160m fishing buoy transmitters!!

73,
Charlie, N0TT


_
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Re: Topband: Small Loop does not receive weak signal on 160m BOUVET RX SPOILER

[Wes]

Rune has kindly spoken up, making some of this discussion moot but I will 
continue anyway.


I appreciate everyone's comments. With respect to Jim's concerns about QRM I 
have thought about that, but did not mention it earlier.


I use DX Atlas, in fact I have presented about the program to my DX club and 
used 3Y has an example of using the program for planning.  (If you don't use it, 
you really should.)


DX Atlas shows that the optimum time for me is about 4:00 UTC. Whether or not 3Y 
is on at that time is conjecture, but for planning, you have to start 
somewhere.  Looking at that time, most of the world's hams are in darkness.  Of 
biggest concern,  QRM wise is EU.  Using France as a proxy, the path is 0 deg 
azimuth and about 7,000 miles, the path to me is 270 degrees and 9,000 miles.  
EU has about 9 hours of common darkness, S. AZ has about 3.  One can only hope 
for selective calling.


I may speak more about RX antennas in another message.

Wes  N7WS

On 12/23/2022 9:34 PM, Jim Brown wrote:

On 12/23/2022 8:12 PM, n...@comcast.net wrote:

I missed the second question.


I understand Wes's point quite well. I have friends who operate 6M from very 
remote places where there is no local noise to light up rare grids. They're 
rare because no one lives there to create noise.


The vast majority of active hams are surrounded by a LOT of noise generated by 
electronics in their own homes and those of their neighbors, as well from 
power lines, street lighting, and other sources. WE are the ones who most need 
serious RX antennas (and also to devote our energies to killing as much as 
possible of our noise at the source).


The difference in local noise between what WE hear and what the DX hears can 
easily be 20 dB.


What Wes may be missing is that the DX may be hearing stations from multiple 
directions, callers from areas with easy prop to them may be MUCH stronger 
than callers from areas that must be worked under exactly the right conditions 
and for rather short time windows, and that those loud callers may have a 
tendency to not stop calling. :) THAT'S where serious RX antennas can help at 
the DX location.


And as both Wes and I have observed, great system engineering involves 
devising systems to solve specific problems. One size never fits all.


73, Jim K9YC
_
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Re: Topband: Small Loop does not receive weak signal on 160m BOUVET RX SPOILER

[David Raymond]

This antenna will not be effective on TB regardless of the preamp used.  
Hopefully they won't be fighting much noise allowing the TX antenna to 
hear reasonably well.


73 and Christmas Blessings/Happy Holidays. . . Dave, W0FLS

On 12/23/2022 7:46 PM, JC wrote:


Hi topband lovers

  


Some friends contact me with deep concerns about the next Bouvet DX expedition 
receiver antenna called SALAD

  


   
Salad antenna

  


I understand the concerns, Bouvet on 160m is a lifetime opportunity for most 
top-banders!

  


When Doug NX4D, me N4IS and Dr Dallas started to try to understand the 
limitation of the new Waller Flag, the first big question was;

  


How small a loop antenna can be to receive weak signal on 160, or MW?

  


Dr. Dallas Lankford III (SK), measured the internal noise of a small loop. 
15x15 FT on his quiet QTH, and wrote a paper with the derivation necessary to 
calculate the thermal noise of a small loop. The study most important point was:

  


The sensitivity of small loop antennas can be limited by internally generated 
thermal noise which is a characteristic of the loop itself. Even amplifying the 
loop output with the lowest noise figure preamp available may not improve the 
loop sensitivity if manmade noise drops low enough

  


The noise on Bouvet island will be very low, < -120 dBm at 500Hz,  and for sure 
the internal thermal noise of the prosed RX antenna will limit the reception of 
weak signals on 160m, it may work on 80 and above, but for 160 m, it will be a set 
up for failure.

  


Why not a single, trustable beverage antenna over the ice or snow?? Or a proved 
K9AY or a DHDL??

  


Below is the almost good transcript of the original pdf Flag Theory, for the 
long answer.

  

  


73’s

JC

N4IS

  


Flag Theory
Dallas Lankford, 1/31/09, rev. 9/9/09


The derivation which follows is a variation of Belrose's classical derivation 
for ferrite rod loop antennas,
“Ferromagnetic Loop Aerials,” Wireless Engineer, February 1955, 41– 46.


Some people who have not actually compared the signal output of a flag antenna 
to other small antennas have expressed their opinions to me that the signal 
output of a flag antenna has great attenuation compared to those other small 
antennas, such as loops and passive verticals. Their opinions are wrong. One 
should never express opinions which are based, say, on computer simulations 
alone, without actual measurements. The development below is based on physics 
(including Maxwell's equations), mathematics, and measurements.


Measurements have confirmed that the flag signal to noise formula derived below 
is approximately correct despite EZNEC simulations to the contrary. For 
example, EZNEC simulation of a 15' square loop at 1 MHz predicts its gain is 
about +4 dbi, while on the other hand EZNEC simulation of a 15' square flag at 
1 MHz predicts its gain is about –46 dBi. But if you construct such a loop and 
such a flag and observe the signal strengths produced by them for daytime 
groundwave MW signals, you will find that the maximum loop and flag signal 
outputs are about equal. Although somewhat more difficult to judge, the 
nighttime sky wave MW signals are also about equal.


Also, the signal to noise ratio formula below for flag arrays has been verified 
by manmade noise measurements in the 160 meter band using a smaller flag array 
than the MW flag array discussed below. Several years ago a similar signal to 
noise ratio formula for small un-tuned (broadband) loop antennas was verified 
at the low end of the NDB band.


The signal voltage es in volts for a one turn loop of area A in meters and a 
signal of wavelength λ for a given radio wave is

  


es = [2πA Es /λ] COS(θ)

  


where Es is the signal strength in volts per meter and θ is the angle between 
the plane of the loop and the radio wave. It is well known that if an 
omnidirectional antenna, say a short whip, is attached to one of the output 
terminals of the loop and the phase difference between the loop and vertical 
and the amplitude of the whip are adjusted to produce a cardioid patten, then 
this occurs for a phase difference of 90 degrees and a whip amplitude equal to 
the amplitude of the loop, and the signal voltage in this case is

  


es = [2πA Es /λ] [1 + COS(θ)]

.
Notice that the maximum signal voltage of the cardioid antenna is twice the 
maximum signal voltage of the loop (or vertical) alone.

A flag antenna is a one turn loop antenna with a resistance of several hundred 
ohms inserted at some point into the one turn. With a rectangular turn, with 
the resistor appropriately placed and adjusted for the appropriate value, the 
flag antenna will generate a cardioid pattern. The exact mechanism by which 
this occurs is not given here. Nevertheless, based on measurements, the flag  
antenna signal voltage is approximately the same as the cardioid pattern given 
above. The 

Re: Topband: Small Loop does not receive weak signal on 160m BOUVET RX SPOILER

[n0tt1]

I was one of the 160m ops at "nearby" FT5XO.  I can tell you that when
the
WX was good the TX antennas worked very well for receiving.  When the
WX turned bad, such as during the snow storm we worked through, the 160m
TX antennas
were very noisyjust as noisy as those anywhere on the planet.

Don't get me started about those awful 160m fishing buoy transmitters!!

73,
Charlie, N0TT

On Fri, 23 Dec 2022 19:45:28 -0700 Wes  writes:
> All interesting.  But let me ask (and standby for flames) what is 
> wrong with 
> them simply listening on the TX antenna?
> 
> I know, I know, conventional wisdom says that you can't possibly 
> work 160 DX 
> without a separate RX antenna.  I'll confess that I am a little 
> pistol and will 
> never be on the TB Honor Roll, but I got on the band just to add 
> another DXCC 
> band to my collection (now nine).  I'm now at 144 confirmed, 
> running just 500W 
> and a 55' inverted-L on both TX and RX. Generally speaking I hear 
> better that I 
> get out.
> 
> Looking at my chances of working 3Y the optimum time is their 
> sunrise (~3:30Z) 
> when I am in complete darkness and straight across the terminator. 
> They will 
> have the sunlit ocean to their rear and the S. American landmass 
> toward me.  
> Maybe someone can enlighten me, but I fail to see how a directional 
> antenna will 
> improve the SNR of my signal at their end.
> 
> Wes  N7WS
> 
> 
> On 12/23/2022 6:46 PM, JC wrote:
> > Hi topband lovers
> >
> >   
> >
> > Some friends contact me with deep concerns about the next Bouvet 
> DX expedition receiver antenna called SALAD
> >
> >   
> >
> >   
>
 
>  Salad antenna
> >
> >   
> >
> > I understand the concerns, Bouvet on 160m is a lifetime 
> opportunity for most top-banders!
> >
> >   
> >
> > When Doug NX4D, me N4IS and Dr Dallas started to try to understand 
> the limitation of the new Waller Flag, the first big question was;
> >
> >   
> >
> > How small a loop antenna can be to receive weak signal on 160, or 
> MW?
> >
> >   
> >
> > Dr. Dallas Lankford III (SK), measured the internal noise of a 
> small loop. 15x15 FT on his quiet QTH, and wrote a paper with the 
> derivation necessary to calculate the thermal noise of a small loop. 
> The study most important point was:
> >
> >   
> >
> > The sensitivity of small loop antennas can be limited by internally 
> generated thermal noise which is a characteristic of the loop 
> itself. Even amplifying the loop output with the lowest noise figure 
> preamp available may not improve the loop sensitivity if manmade 
> noise drops low enough
> >
> >   
> >
> > The noise on Bouvet island will be very low, < -120 dBm at 500Hz,  
> and for sure the internal thermal noise of the prosed RX antenna 
> will limit the reception of weak signals on 160m, it may work on 80 
> and above, but for 160 m, it will be a set up for failure.
> >
> >   
> >
> > Why not a single, trustable beverage antenna over the ice or 
> snow?? Or a proved K9AY or a DHDL??
> >
> >   
> >
> > Below is the almost good transcript of the original pdf Flag 
> Theory, for the long answer.
> >
> >   
> >
> >   
> >
> > 73�s
> >
> > JC
> >
> > N4IS
> >
> >   
> >
> > Flag Theory
> > Dallas Lankford, 1/31/09, rev. 9/9/09
> >
> >
> > The derivation which follows is a variation of Belrose's classical 
> derivation for ferrite rod loop antennas,
> > �Ferromagnetic Loop Aerials,� Wireless Engineer, February 
> 1955, 41� 46.
> >
> >
> > Some people who have not actually compared the signal output of a 
> flag antenna to other small antennas have expressed their opinions 
> to me that the signal output of a flag antenna has great attenuation 
> compared to those other small antennas, such as loops and passive 
> verticals. Their opinions are wrong. One should never express 
> opinions which are based, say, on computer simulations alone, 
> without actual measurements. The development below is based on 
> physics (including Maxwell's equations), mathematics, and 
> measurements.
> >
> >
> > Measurements have confirmed that the flag signal to noise formula 
> derived below is approximately correct despite EZNEC simulations to 
> the contrary. For example, EZNEC simulation of a 15' square loop at 
> 1 MHz predicts its gain is about +4 dbi, while on the other hand 
> EZNEC simulation of a 15' square flag at 1 MHz predicts its gain is 
> about �46 dBi. But if you construct such a loop and such a flag 
> and observe the signal strengths produced by them for daytime 
> groundwave MW signals, you will find that the maximum loop and flag 
> signal outputs are about equal. Although somewhat more difficult to 
> judge, the nighttime sky wave MW signals are also about equal.
> >
> >
> > Also, the signal to noise ratio formula below for flag arrays has 
> been verified by manmade noise measurements in the 160 meter band 
> using a smaller flag array than the MW flag array discussed below. 
> Several 

Re: Topband: Small Loop does not receive weak signal on 160m BOUVET RX SPOILER

[Jim Brown]

On 12/23/2022 8:12 PM, n...@comcast.net wrote:

I missed the second question.


I understand Wes's point quite well. I have friends who operate 6M from 
very remote places where there is no local noise to light up rare grids. 
They're rare because no one lives there to create noise.


The vast majority of active hams are surrounded by a LOT of noise 
generated by electronics in their own homes and those of their 
neighbors, as well from power lines, street lighting, and other sources. 
WE are the ones who most need serious RX antennas (and also to devote 
our energies to killing as much as possible of our noise at the source).


The difference in local noise between what WE hear and what the DX hears 
can easily be 20 dB.


What Wes may be missing is that the DX may be hearing stations from 
multiple directions, callers from areas with easy prop to them may be 
MUCH stronger than callers from areas that must be worked under exactly 
the right conditions and for rather short time windows, and that those 
loud callers may have a tendency to not stop calling. :) THAT'S where 
serious RX antennas can help at the DX location.


And as both Wes and I have observed, great system engineering involves 
devising systems to solve specific problems. One size never fits all.


73, Jim K9YC
_
Searchable Archives: http://www.contesting.com/_topband - Topband Reflector

Re: Topband: Small Loop does not receive weak signal on 160m BOUVET RX SPOILER

[n4is]

Wes 

I missed the second question. How a receiving antenna can help on your signal 
there. The RX antenna is good as the directivity or RDF. Based on my 
measurements and extensive experiments with the Waller Flag, for 1 db improve 
in RDF you can get 2db or more on signal to noise ratio aiming at the signal, 
plus de rejection on side and back nulls. You can check more about this on my 
webinar at WWROF

https://wwrof.org/webinar-archive/high-performance-rx-antennas-for-a-small-lot/

I measured 2db over 100 tests or more, including using WSJT SN readings. It is 
a practical result, not just computer simulation.

With a good RX antenna 11 to 12 dB RDF you can work 150 counties on 160 any 12 
month period. I did it for 10 years. Using  a Waller Flag, Doug NX4D, worked 
314 on 160m  from a 1/5 acre lot. All CW.

I  started with a vertical WF on 2003, and an Horizontal Waller Flag in 2010, 
the noise here in my city lot is very high now, and my Vertical Waller Flag is 
down because the HWF does not see the vertical manmade noise, so I have no 
noise on the HWF. I worked in the last 10 year close to 300 countries on 160m, 
only CW, and I am now at 305, however I heard over 320 countries down here in 
South Florida from a city lot. The VWF can dig signals on CW 10 db below noise 
and my HWF can dig 20 db bellow noise, when you compare with the TX antenna. I 
can measure that as well, with 2 instances on WSJT on my radio two identical 
receivers, a signal -20 SNR on the vertical shows a 0 db on the HWF. 

More information about the HWF here >

https://wwrof.org/webinar-archive/n4is-waller-flag-construction/

You can download the presentation too, Doug and I do not provide any additional 
support or question anymore, we spent hundred of hours on it and few people 
listened us.

So, conclusion a RX antenna can dig you signal out of the noise.

73's
JC
N4IS




-Original Message-
From: Topband  On Behalf Of Wes
Sent: Friday, December 23, 2022 9:45 PM
To: topband@contesting.com
Subject: Re: Topband: Small Loop does not receive weak signal on 160m BOUVET RX 
SPOILER

All interesting.  But let me ask (and standby for flames) what is wrong with 
them simply listening on the TX antenna?

I know, I know, conventional wisdom says that you can't possibly work 160 DX 
without a separate RX antenna.  I'll confess that I am a little pistol and will 
never be on the TB Honor Roll, but I got on the band just to add another DXCC 
band to my collection (now nine).  I'm now at 144 confirmed, running just 500W 
and a 55' inverted-L on both TX and RX. Generally speaking I hear better that I 
get out.

Looking at my chances of working 3Y the optimum time is their sunrise (~3:30Z) 
when I am in complete darkness and straight across the terminator. They will 
have the sunlit ocean to their rear and the S. American landmass toward me. 
Maybe someone can enlighten me, but I fail to see how a directional antenna 
will improve the SNR of my signal at their end.

Wes  N7WS


On 12/23/2022 6:46 PM, JC wrote:
> Hi topband lovers
>
>   
>
> Some friends contact me with deep concerns about the next Bouvet DX 
> expedition receiver antenna called SALAD
>
>   
>
>   
> <http://www.lz1aq.signacor.com/docs/active-wideband-directional-antenn
> a.php>  Salad antenna
>
>   
>
> I understand the concerns, Bouvet on 160m is a lifetime opportunity for most 
> top-banders!
>
>   
>
> When Doug NX4D, me N4IS and Dr Dallas started to try to understand the 
> limitation of the new Waller Flag, the first big question was;
>
>   
>
> How small a loop antenna can be to receive weak signal on 160, or MW?
>
>   
>
> Dr. Dallas Lankford III (SK), measured the internal noise of a small loop. 
> 15x15 FT on his quiet QTH, and wrote a paper with the derivation necessary to 
> calculate the thermal noise of a small loop. The study most important point 
> was:
>
>   
>
> The sensitivity of small loop antennas can be limited by internally 
> generated thermal noise which is a characteristic of the loop itself. 
> Even amplifying the loop output with the lowest noise figure preamp 
> available may not improve the loop sensitivity if manmade noise drops 
> low enough
>
>   
>
> The noise on Bouvet island will be very low, < -120 dBm at 500Hz,  and for 
> sure the internal thermal noise of the prosed RX antenna will limit the 
> reception of weak signals on 160m, it may work on 80 and above, but for 160 
> m, it will be a set up for failure.
>
>   
>
> Why not a single, trustable beverage antenna over the ice or snow?? Or a 
> proved K9AY or a DHDL??
>
>   
>
> Below is the almost good transcript of the original pdf Flag Theory, for the 
> long answer.
>
>   
>
>   
>
> 73’s
>
> JC
>
> N4IS
>
>   
>
> Flag Theory
> Dallas Lankford, 1/31

Re: Topband: Small Loop does not receive weak signal on 160m BOUVET RX SPOILER

[Wes]

All interesting.  But let me ask (and standby for flames) what is wrong with 
them simply listening on the TX antenna?


I know, I know, conventional wisdom says that you can't possibly work 160 DX 
without a separate RX antenna.  I'll confess that I am a little pistol and will 
never be on the TB Honor Roll, but I got on the band just to add another DXCC 
band to my collection (now nine).  I'm now at 144 confirmed, running just 500W 
and a 55' inverted-L on both TX and RX. Generally speaking I hear better that I 
get out.


Looking at my chances of working 3Y the optimum time is their sunrise (~3:30Z) 
when I am in complete darkness and straight across the terminator. They will 
have the sunlit ocean to their rear and the S. American landmass toward me.  
Maybe someone can enlighten me, but I fail to see how a directional antenna will 
improve the SNR of my signal at their end.


Wes  N7WS


On 12/23/2022 6:46 PM, JC wrote:

Hi topband lovers

  


Some friends contact me with deep concerns about the next Bouvet DX expedition 
receiver antenna called SALAD

  


    
Salad antenna

  


I understand the concerns, Bouvet on 160m is a lifetime opportunity for most 
top-banders!

  


When Doug NX4D, me N4IS and Dr Dallas started to try to understand the 
limitation of the new Waller Flag, the first big question was;

  


How small a loop antenna can be to receive weak signal on 160, or MW?

  


Dr. Dallas Lankford III (SK), measured the internal noise of a small loop. 
15x15 FT on his quiet QTH, and wrote a paper with the derivation necessary to 
calculate the thermal noise of a small loop. The study most important point was:

  


The sensitivity of small loop antennas can be limited by internally generated 
thermal noise which is a characteristic of the loop itself. Even amplifying the 
loop output with the lowest noise figure preamp available may not improve the 
loop sensitivity if manmade noise drops low enough

  


The noise on Bouvet island will be very low, < -120 dBm at 500Hz,  and for sure 
the internal thermal noise of the prosed RX antenna will limit the reception of 
weak signals on 160m, it may work on 80 and above, but for 160 m, it will be a set 
up for failure.

  


Why not a single, trustable beverage antenna over the ice or snow?? Or a proved 
K9AY or a DHDL??

  


Below is the almost good transcript of the original pdf Flag Theory, for the 
long answer.

  

  


73’s

JC

N4IS

  


Flag Theory
Dallas Lankford, 1/31/09, rev. 9/9/09


The derivation which follows is a variation of Belrose's classical derivation 
for ferrite rod loop antennas,
“Ferromagnetic Loop Aerials,” Wireless Engineer, February 1955, 41– 46.


Some people who have not actually compared the signal output of a flag antenna 
to other small antennas have expressed their opinions to me that the signal 
output of a flag antenna has great attenuation compared to those other small 
antennas, such as loops and passive verticals. Their opinions are wrong. One 
should never express opinions which are based, say, on computer simulations 
alone, without actual measurements. The development below is based on physics 
(including Maxwell's equations), mathematics, and measurements.


Measurements have confirmed that the flag signal to noise formula derived below 
is approximately correct despite EZNEC simulations to the contrary. For 
example, EZNEC simulation of a 15' square loop at 1 MHz predicts its gain is 
about +4 dbi, while on the other hand EZNEC simulation of a 15' square flag at 
1 MHz predicts its gain is about –46 dBi. But if you construct such a loop and 
such a flag and observe the signal strengths produced by them for daytime 
groundwave MW signals, you will find that the maximum loop and flag signal 
outputs are about equal. Although somewhat more difficult to judge, the 
nighttime sky wave MW signals are also about equal.


Also, the signal to noise ratio formula below for flag arrays has been verified 
by manmade noise measurements in the 160 meter band using a smaller flag array 
than the MW flag array discussed below. Several years ago a similar signal to 
noise ratio formula for small un-tuned (broadband) loop antennas was verified 
at the low end of the NDB band.


The signal voltage es in volts for a one turn loop of area A in meters and a 
signal of wavelength λ for a given radio wave is

  


es = [2πA Es /λ] COS(θ)

  


where Es is the signal strength in volts per meter and θ is the angle between 
the plane of the loop and the radio wave. It is well known that if an 
omnidirectional antenna, say a short whip, is attached to one of the output 
terminals of the loop and the phase difference between the loop and vertical 
and the amplitude of the whip are adjusted to produce a cardioid patten, then 
this occurs for a phase difference of 90 degrees and a whip amplitude equal to 
the amplitude of the loop, and the signal voltage 

Re: Topband: Small Loop does not receive weak signal on 160m BOUVET RX SPOILER

[n4is]

Doug NX4D asked me to add his comments,

Hey JC and Topbanders,  This is meant as a suggestion, not a criticism. 

The reason I sounded an alarm to JC was the concern that the proposed SALAD/ 
LZ1AQ 160m receive loops by the upcoming Bouvet DXpedition/ 3Y0J are  much too 
small for receiving weak signals on 160m.  With the current poor 160m condx, it 
would be a shame for them to go to all this trouble and expense, then not be 
able to pull in medium to weaker sigs with the loops.  I would suggest the 
loop(s) be at least 10 ft (3m) diameter.

>From experience I found that my original WF with small phased loops could not 
>hear the weakest sigs others around me were hearing, due to being thermal 
>noise limited.  The solution was to make the loops much larger, by which I 
>could then hear all sigs very well.

73/ NX4D

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