Terry,
Please read the last paragraph of this 1991 paper:
http://www.kongsfjord.no/dl/Antennas...ensitivity.pdf

"Seeing-I-dawg" wrote in message
...

wrote in message
oups.com...

Seeing-I-dawg wrote:
Do you currently use a longwire or dipole or have the real estate for
one?
Have you been considering the ALA1530+ instead?

I exchanged emails with Wellbrook about using the ALA100 with my
current
70M
fullwave Horizontal loop.

About Horizontal loops
http://www.cebik.com/wire/hl.html
http://www.cebik.com/fdim/atl1.html
http://www.cebik.com/wire/horloop.html

About ALA100 http://www.wellbrook.uk.com/ALA100b.html

The ALA100 will allow me to use a coax feeder instead of the noise
prone
450ohm ladder-line and dispense with the
antenna tuner/matchbox.

Per Wellbrook, "You may also find that a smaller vertical loop with
ALA100
will give better directivity for MW plus very high gain at HF. The
ALA100
will out perform the ALA1530+ , because the loop area is much larger."

So if you are considering a ALA1530+ and are currently occupying real
estate
with a long-wire or dipole, you may consider joining the ends with the
ALA100 for a loop in either the horizontal or vertical plane.

Here's to the '06/'07 DXing season!
Post your logs and good luck.

First, please understand and accept that I have nothing against the
Wellbrook company or thier products. Their web page has clearly helped
many newbie SWL learn how to errect
a "long" wire antenna. And many people swear by all of their loops.
However, my
experience suggests loops may not be the do all end all.

For a alternative perspective please read the research by Dallas
Lanford at
http://www.kongsfjord.no/ "Measurements of Some Antennas Signal to
Man Made Noise Ratios"

Every situation is different. And the guy I traded theALA 1530 to loves
it.
Perhaps under extreme noise situations loops are better.

My recent experiments mirrored Dallas' experiences.

My "shack" is still disassembled. I hope to have it up and running by
the
weekend. 2 days of rain really messed with my plans.

Terry


Terry, this post wasn't intended as an addendum to my previous post to you
about horizontal loops.

I don't/can't dispute the claims about verticals Vs. loops regarding
noise.
Generally, a vertical antenna is ideal for DXing since its main "lobe" is
towards the horizon (in all directions). But I know you knew that. Could
that account for the difference in S/MMN ratio in the Kongsfjord
comparison?

The two main practical advantages of loops is steerability or nulling with
relatively small loops and inherently broadbanded performance with
relatively large (full wave) loops. The Wellbrook ALA1530+ claims both -
broadband performance using a broadband amplifier and steerability using a
small "shielded" loop.

The ALA1530+ design is different from the ALA100 in that the ALA1530+
"loop"
is inside an aluminum tube/shield. Alegedly this shield(?) rejects the
nearby Electric-field which supposedly contains the noise component and
amplifies the Magnetic-field which supposedly does not contain the noise
[Electro-Magnetic wave = RF]. The ALA100 wire antenna component has no
shield so how can it reject nearby Electric-fields containing noise?
Additionally, in the Kongsfjord power line comparison (45Ft vertical Vs.
Loop) the vertical's main lobe is at the horizon (under the powerline).
The
lobes of the loop are very much like that of a dipole (above the
horizon) -
more closely aimed at the powerline. Therefor, I think the Kongsfjord
comparison is missplaced. But I am not versed with the noise argument
related to loops Vs. verticals.

My point to my original post in this thread was that if you already have a
dipole or longwire (which is inherently NOT broadbanded) you can use the
ALA100 to convert them into a loop. The Wellbrook ALA100 product is
simply
a broadband amplifier (I suspect similiar to the 1530). It does not
include
any "antenna" or coax. You supply the antenna wire yourself - an existing
dipole or longwire folded into some resemblance to a large broadbanded
loop.
The shape is not critical as long as the wires are not too close.

Converting a dipole or longwire into a broadbanded loop and adding a
broadbanded amplifier like the ALA100 seems like a good idea. Although the
ALA100 was meant to be used with a relatively medium sized rotatable
vertical loop, http://www.wellbrook.uk.com/ALA100b.html
Wellbrook's email in essence said it will work with any reasonably sized
loop oriented in any plane - vertically or horizontally.

My antenna goal is to have one antenna and to squeeze as much performance
out of it on as many frequencies (500KHz-30MHz) as possible. That, my
friend, can be most closely accomplished with a large loop. However, I am
intriqed by the 15ft vertical that is diagramed at the Kongsfjord noise
measurments link.

There are no ideal antennas. Just antennas with ideal applications.

Please read the last paragraph of this 1991 paper:
http://www.kongsfjord.no/dl/Antennas...ensitivity.pdf

Generally, a vertical antenna is ideal for DXing since its main "lobe"
is
towards the horizon (in all directions). But I know you knew that.
Could
that account for the difference in S/MMN ratio in the Kongsfjord
comparison?
....
Additionally, in the Kongsfjord power line comparison (45Ft vertical Vs.
Loop) the vertical's main lobe is at the horizon (under the powerline).
The lobes of the loop are very much like that of a dipole (above the
horizon) - more closely aimed at the powerline.

Addition part II:
The powerline noise is horizontally polarized while a vertical antenna is
vertically polarized. The noise was 90 degrees out of phase [typically a
difference of what? 6db?]. Thus the vertical antenna in this situation was
at a distinct advantage.
Out of phase and major lobe pointed away from the powerline.

A square loop, as is the ALA100 loop, is both horizontally and vertically
polarized. Thus more sensitive to receiving the horizontally polarized
powerline noise compared to a vertical antenna.

On Oct 4, 6:36 pm, "Seeing-I-dawg" wrote:
Terry,
Please read the last paragraph of this 1991 paper:http://www.kongsfjord.no/dl/Antennas...ensitivity.pdf

Yep, the directivity of a loop is what the "magic" is all about.

Dallas' active dipole exhibited better, as in a better null,
directivity from 100KHz (loran)
to CB. A good buddy ratchet mouth about 3 miles from me makes a great
far field test
signal.

The Feb 1955 "Wireless Engineer" paper by J.S.Belrose gives some very
usefull
info on loop. I am not saying loops have no place. Jeff, the guy I
traded the wellbrook
to, loves it. In his RF hell it works better then anyother antenna he
has tried. Once I
get the shack rebuilt I intend to take my latest version of Dallas'
active dipole there to
see if the tighter null will help. I plan on building the WL1030 that
RHF mentioned.
Martinn Hagg's design look workable. I have major doubts about wide
band OpAmps
in a harsh RF task, but I am willing to give it a try.

I suspect that Dallas' Ultra Linear Amplifier will work as well as the
Wellbrook loop maker.
And it would be a lot less expensive. The Kiwa amp version 2, should
also work. It will
need a ?1:! broadband transformer but it is a pretty good amp.

The Belrose paper explained why the 2 different heads I have for my
McKay-Dymek DA5
behave so differently under temperature extremes. The unit that
performs the best under
wide, 100F to -20F temperature swings has a slot lengthwise to the
hollow center.

I have been in a heated conversation with some SWL aquantances here in
the central
KY area about how long a "long wire" should be. And at what length does
it start degrading
radio performance. Most SWL or hams, or even professional RF engineers,
either don' know,
or refuse to think about, the effects too much signal can cause. Front
ends and first mixers
behave very badly with 1dB to many. I envy DXace becuase he clearly has
a superior RF
location with a low enough background RF to degrade his R8B. Sadly
around here, anything
over 100' is more likely to cause problems then help you dig out the
really weak DX.

Jeff, he lives in a downtown Lexington condo, has had nasty experiences
with out of band
overload causing all sorts of receiver misbehavoir. And he has an
AOR7030, not the plus
version.

Terry

You pretty much nailed it. No antenna is ideal. The fun is finding one,
two, three... that work respectably with your gear, your particular RF
environment, and your listening goals. That could be anything from a
beverage to a rubber duck :-)

IM - yech! Outboard filter(s) to knock down the offending station(s)
perhaps?

Regarding longwires; Why? It will have peaks and valleys in reception
across the RF spectrum. Join the ends to make a horizontal loop and that
will disappear - linear response.

I respect Guy Atkins remarks regarding his dissappointment with the
Wellbrook 1530. I have never owned a loop of that size and type and have
always been apprehensive about trying it. Noise isn't a huge problem here.
If I can replace my 450 ohm ladder-line feed to my horizontal loop with coax
(using the ALA100 amp) I may be able to eliminate most of the remaining
noise and pick up a db or two (except I can no longer transmit into it).

I no longer am a DYI with electronics. I just don't have the time or
patience to gather the parts, solder the board and cross my fingers. If
someone sells an assembled Dallas amplifier I may bite.

I am really getting excited about the software defined radio Guy Atkins
uses. After listening to his sound bites on his SDR-1000 blog I have to
lock up the credit cards. I would really enjoy attending one of his
DXpeditions.

EOM


wrote in message
ups.com...


On Oct 4, 6:36 pm, "Seeing-I-dawg" wrote:
Terry,
Please read the last paragraph of this 1991
paper:http://www.kongsfjord.no/dl/Antennas...ensitivity.pdf

Yep, the directivity of a loop is what the "magic" is all about.

Dallas' active dipole exhibited better, as in a better null,
directivity from 100KHz (loran)
to CB. A good buddy ratchet mouth about 3 miles from me makes a great
far field test
signal.

The Feb 1955 "Wireless Engineer" paper by J.S.Belrose gives some very
usefull
info on loop. I am not saying loops have no place. Jeff, the guy I
traded the wellbrook
to, loves it. In his RF hell it works better then anyother antenna he
has tried. Once I
get the shack rebuilt I intend to take my latest version of Dallas'
active dipole there to
see if the tighter null will help. I plan on building the WL1030 that
RHF mentioned.
Martinn Hagg's design look workable. I have major doubts about wide
band OpAmps
in a harsh RF task, but I am willing to give it a try.

I suspect that Dallas' Ultra Linear Amplifier will work as well as the
Wellbrook loop maker.
And it would be a lot less expensive. The Kiwa amp version 2, should
also work. It will
need a ?1:! broadband transformer but it is a pretty good amp.

The Belrose paper explained why the 2 different heads I have for my
McKay-Dymek DA5
behave so differently under temperature extremes. The unit that
performs the best under
wide, 100F to -20F temperature swings has a slot lengthwise to the
hollow center.

I have been in a heated conversation with some SWL aquantances here in
the central
KY area about how long a "long wire" should be. And at what length does
it start degrading
radio performance. Most SWL or hams, or even professional RF engineers,
either don' know,
or refuse to think about, the effects too much signal can cause. Front
ends and first mixers
behave very badly with 1dB to many. I envy DXace becuase he clearly has
a superior RF
location with a low enough background RF to degrade his R8B. Sadly
around here, anything
over 100' is more likely to cause problems then help you dig out the
really weak DX.

Jeff, he lives in a downtown Lexington condo, has had nasty experiences
with out of band
overload causing all sorts of receiver misbehavoir. And he has an
AOR7030, not the plus
version.

Terry

Seeing-I-dawg wrote:
You pretty much nailed it. No antenna is ideal. The fun is finding one,
two, three... that work respectably with your gear, your particular RF
environment, and your listening goals. That could be anything from a
beverage to a rubber duck :-)

IM - yech! Outboard filter(s) to knock down the offending station(s)
perhaps?

Regarding longwires; Why? It will have peaks and valleys in reception
across the RF spectrum. Join the ends to make a horizontal loop and that
will disappear - linear response.

I respect Guy Atkins remarks regarding his dissappointment with the
Wellbrook 1530. I have never owned a loop of that size and type and have
always been apprehensive about trying it. Noise isn't a huge problem here.
If I can replace my 450 ohm ladder-line feed to my horizontal loop with coax
(using the ALA100 amp) I may be able to eliminate most of the remaining
noise and pick up a db or two (except I can no longer transmit into it).

I no longer am a DYI with electronics. I just don't have the time or
patience to gather the parts, solder the board and cross my fingers. If
someone sells an assembled Dallas amplifier I may bite.

I am really getting excited about the software defined radio Guy Atkins
uses. After listening to his sound bites on his SDR-1000 blog I have to
lock up the credit cards. I would really enjoy attending one of his
DXpeditions.

EOM

Guy Atkins is very lucky to live in what must be one of the quitest RF
environments
around. My home RF level isn't as bad as I had thought, I know see what
real
bad RFI is, but at that there is very little I can hear on a AOR7030+,
R8B, or a R2000.
The first 2 recivers do a much beter job in very crowded band
conditions with very strong
signlas next to weak ones that I am intereted in.

On a "remote" mountain top in eastern KY I enjoyed pushing the AOR to
the limits.
That quite location showed the difference between a great receiver and
a much more
modest (R2000) receiver.

Perversly better locations deserve better recveivers. Since the local
noise floor sets
the limit to our reception it makes sense but it does feel odd. I have
been busy trying
to eliminate, or at least reduce, any unwanted RF noise. Sadly while I
have had great
success at eliminating the RF noise emitted by/within our home. We got
rid of our
desk top PCs, tossed the TV and similar steps have reduced my noise
floor as much
as I can. Too bad I can;t convine my nieghbors to limit thier RFI. I
had hoped the
Wellbrook ALA 1530 would reduce noise from nearby homes, but either
the whole
lopp concept is flawed, which I believe, or my in location all the
noise is "far field" and
a loop won't help.

Terry

wrote
I had hoped the
Wellbrook ALA 1530 would reduce noise from nearby homes, but either
the whole
lopp concept is flawed, which I believe, or my in location all the
noise is "far field" and
a loop won't help.

Curious that Wellbrook states that the 1530 will operate best when it is
about 30ft away from your home and for best MW reception mounted near the
ground. It alegedly performs better on SW when mounted up high at the cost
of MW reception.

Where's that credit card!? LOL

In article . com,
wrote:

Snip

Guy Atkins is very lucky to live in what must be one of the quitest
RF environments around. My home RF level isn't as bad as I had
thought, I know see what real bad RFI is, but at that there is very
little I can hear on a AOR7030+, R8B, or a R2000. The first 2
recivers do a much beter job in very crowded band conditions with
very strong signlas next to weak ones that I am intereted in.

On a "remote" mountain top in eastern KY I enjoyed pushing the AOR to
the limits. That quite location showed the difference between a great
receiver and a much more modest (R2000) receiver.

Perversly better locations deserve better recveivers. Since the local
noise floor sets the limit to our reception it makes sense but it
does feel odd. I have been busy trying to eliminate, or at least
reduce, any unwanted RF noise. Sadly while I have had great success
at eliminating the RF noise emitted by/within our home. We got rid of
our desk top PCs, tossed the TV and similar steps have reduced my
noise floor as much as I can. Too bad I can;t convine my nieghbors to
limit thier RFI. I had hoped the Wellbrook ALA 1530 would reduce
noise from nearby homes, but either the whole lopp concept is flawed,
which I believe, or my in location all the noise is "far field" and a
loop won't help.

I would believe the latter. The "whole loop concept" is not flawed.

--
Telamon
Ventura, California

wrote in message
ups.com...
Guy Atkins is very lucky to live in what must be one of the quitest RF
environments
around. My home RF level isn't as bad as I had thought, I know see what
real
bad RFI is, but at that there is very little I can hear on a AOR7030+,
R8B, or a R2000.

Yes, it's very quiet here in the Pacific NW, with the fewest "thunderstorm
days" of any place in the continental USA. In mid-winter, with a Western
Beverage antenna at dawn, aimed out over the Pacific Ocean, you'd swear your
receiver was defective, or the antenna broken. In these conditions,
extremely faint tropical band and foreign (TP) mediumwave signals have a
fighting chance to be heard (assuming a top-notch, low noise receiver like a
AR7030 or my current fave, the SDR-1000.

It was under these mid-winter, dawn enhancement conditions that I heard
tantalizing faint signals around 3174 kHz (variable) in the late 1990s,
which had all the clues of Indonesian "amatir" stations. Think: Indo college
kids back home on holiday or weekend breaks, playing non-stop Indo rock
music with flea-powered transmitters, no IDs, often distorted audio, no
official "RRI" news at the top of the hour, etc. I've heard enough of the
real RRI and RPD Indonesian stations to recognize the Indo amatir (pirate)
station. Similarly, I've logged very low power Australian x-band stations
such as Radio Brisvaani, the Hindi station on 1701 kHz (Brisbane,
Queensland). I'd never have a chance to hear this sort of DX, however, at
home in the suburban RF jungle near Seattle-Tacoma. These catches were on
coastal DXpeditions, under ideal conditions.

I do have pretty low noise levels of the RFI, hash-and-buzz sort at home,
due to the underground AC mains. The main problem are the dozen or so MW
stations registering S-9+40 to S-9+60 dB on the SDR's (calibrated) signal
meter. My local 1 kw'er, 1450 KSUH in Puyallup, is a bit over 1 mile from
home. When I had a 700 ft. Beverage antenna aimed at my Asian targets, the
antenna unfortunately was oriented right at KSUH, too. The signal on 1450
from that antenna registered -13 dBm, which is, I believe, around S-9+65 dB.
This is an example of what the trans-Pacific MW stations need to fight
through to be heard in a suburban location like this. So far, I'm finding
the Wellbrook ALA 100 on a rotator does just fine for snagging the foreign
MW DX that makes it through the RF jungle; a Beverage is no advantage.

73,

Guy Atkins
Puyallup, WA
www.sdr-1000.blogspot.com

Guy is so right about the joys of DXing in a very low noise environment,
such as the Pacific coast Grayland site. I takes a lot of research and
running around to find an "ideal" low noise DX site and on our crowded
planet they become harder and harder to find.

I found such a site in a remote part of our Atlantic coast,Seefontein, miles
from the nearest town and miles from the nearest powerline. It's just bliss
to have that phenomena that Guy describes: when the noise on the antenna's
is so low you start checking to see if in fact they are connected. It is
such a joy to hear stations thousand's of miles away waft in over the
airwaves as clear as a bell, yet the signal strength is so low it doesn't
even move your "S" meter. What a thrill!

That's why some of us serious DXer's travel long distances with considerable
effort in time and money to enjoy these most favourable DX conditions.

Try it = you'll love it..............
--
John Plimmer, Montagu, Western Cape Province, South Africa
South 33 d 47 m 32 s, East 20 d 07 m 32 s
RX Icom IC-756 PRO III with MW mods
Drake SW8 & ERGO software
Sony 7600D, GE SRIII, Redsun RP2100
BW XCR 30, Sangean 803A.
GE circa 50's radiogram
Antenna's RF Systems DX 1 Pro, Datong AD-270
Kiwa MW Loop, POARDT Roelof mini-whip
http://www.dxing.info/about/dxers/plimmer.dx

"Guy Atkins" wrote in message
. ..

Yes, it's very quiet here in the Pacific NW, with the fewest "thunderstorm
days" of any place in the continental USA. In mid-winter, with a Western
Beverage antenna at dawn, aimed out over the Pacific Ocean, you'd swear
your receiver was defective, or the antenna broken. In these conditions,
extremely faint tropical band and foreign (TP) mediumwave signals have a
fighting chance to be heard (assuming a top-notch, low noise receiver like
a AR7030 or my current fave, the SDR-1000.

It was under these mid-winter, dawn enhancement conditions that I heard
tantalizing faint signals around 3174 kHz (variable) in the late 1990s,
which had all the clues of Indonesian "amatir" stations. Think: Indo
college kids back home on holiday or weekend breaks, playing non-stop Indo
rock music with flea-powered transmitters, no IDs, often distorted audio,
no official "RRI" news at the top of the hour, etc. I've heard enough of
the real RRI and RPD Indonesian stations to recognize the Indo amatir
(pirate) station. Similarly, I've logged very low power Australian x-band
stations such as Radio Brisvaani, the Hindi station on 1701 kHz (Brisbane,
Queensland). I'd never have a chance to hear this sort of DX, however, at
home in the suburban RF jungle near Seattle-Tacoma. These catches were on
coastal DXpeditions, under ideal conditions.

I do have pretty low noise levels of the RFI, hash-and-buzz sort at home,
due to the underground AC mains. The main problem are the dozen or so MW
stations registering S-9+40 to S-9+60 dB on the SDR's (calibrated) signal
meter. My local 1 kw'er, 1450 KSUH in Puyallup, is a bit over 1 mile from
home. When I had a 700 ft. Beverage antenna aimed at my Asian targets, the
antenna unfortunately was oriented right at KSUH, too. The signal on 1450
from that antenna registered -13 dBm, which is, I believe, around S-9+65
dB. This is an example of what the trans-Pacific MW stations need to fight
through to be heard in a suburban location like this. So far, I'm finding
the Wellbrook ALA 100 on a rotator does just fine for snagging the foreign
MW DX that makes it through the RF jungle; a Beverage is no advantage.

73,

Guy Atkins
Puyallup, WA
www.sdr-1000.blogspot.com

John Plimmer wrote:
It's just bliss
to have that phenomena that Guy describes: when the noise on the antenna's
is so low you start checking to see if in fact they are connected. It is
such a joy to hear stations thousand's of miles away waft in over the
airwaves as clear as a bell, yet the signal strength is so low it doesn't
even move your "S" meter. What a thrill!


It's a pity these sorts of locations are so few and far between. In
most locations, atmospheric noise is significant *all by itself*.