More on the Wellbrook loops
Steve
have a real edge over the 330S on SW, given its larger aperture. He
replied that he has an ALA 100 attached to a 25m wire Delta loop. This
antenna at HF gives approx. 17-20dB higher gain than the ALA330S and
the ALA1530. That's pretty impressive.
Steve
cuh...@webtv.net
as good for next to nothing.
cuhulin
gravity
<cuh...@webtv.net> wrote in message
news:26433-449...@storefull-3252.bay.webtv.net...
> Too Much Money For The Amount Of Bread.I could rig up something almost
> as good for next to nothing.
> cuhulin
>
pasta has more radiation resistance.
Gravity
Joe Analssandrini
Am I correct that this is an approximate fifty-foot-diameter loop?
If so, it would necessitate outdoor mounting.
Best,
Joe
Joe Analssandrini
No, I don't believe you could. So far, NO ONE has been able to even
match the performance of the Wellbrook loops.
Have you tried? If you do, and you actually succeed, please post a
parts list and directions for an antenna which would cost all of us
"next to nothing." I should appreciate seeing them.
Best,
Joe
Steve
A loop the size of Ikin's would almost certainly have to be mounted
outdoors. However, some folks have wire loops in the attic...probably
not as large as Andy Ikin's loop, but certainly larger than the 1 meter
diameter loop you get with the 1530/330S. The ALA 100 might be just the
ticket for some of these folks, especially since it is, I've heard
several people say, even more resistant to noise pickup than the
1530/330S. So IF the space is available, I can see how, at least for
some, the greater aperture of the ALA 100 would prove a greater
advantage than the nulling capabilities of the smaller loops. The ALA
100 is also significantly less expensive than its smaller brethren.
I also like the fact that the ALA offers you the freedom to experment
with different loop sizes and configurations. This sort of "elbow room"
always appeals to me. It's fun to experiment.
Steve
cuh...@webtv.net
cuhulin
Dale Parfitt
"Steve" <sdan...@speakeasy.net> wrote in message
news:1151268322....@p79g2000cwp.googlegroups.com...
>
> Joe Analssandrini wrote:
>> Dear Steve,
>>
>> Am I correct that this is an approximate fifty-foot-diameter loop?
>>
>> If so, it would necessitate outdoor mounting.
>>
>> Best,
>>
>> Joe
>>
>> Steve wrote:
>> > I fired off a message to Andy Ikin asking him whether the ALA 100 would
>> > have a real edge over the 330S on SW, given its larger aperture. He
>> > replied that he has an ALA 100 attached to a 25m wire Delta loop. This
>> > antenna at HF gives approx. 17-20dB higher gain than the ALA330S and
>> > the ALA1530. That's pretty impressive.
>> >
>> > Steve
>
> A loop the size of Ikin's would almost certainly have to be mounted
> outdoors. However, some folks have wire loops in the attic...probably
> not as large as Andy Ikin's loop, but certainly larger than the 1 meter
> diameter loop you get with the 1530/330S. The ALA 100 might be just the
> ticket for some of these folks, especially since it is, I've heard
> several people say, even more resistant to noise pickup than the
> 1530/330S.
Please, someone share with the group why a shielded loop is less prone to
noise p/u than other antennas- other than the fact that if done properly, it
should have 2 deep nulls and thus be able to be rotated to place a single
noise source in one of the nulls.
I have a homebrew 7' shielded loop- with a broadband amp just like the
Wellbrook. It is no less noisy than my classic L-C loop other than the fact
that the 2 nulls appear to be a tad deeper.
To dispell the black magic:
http://www.w8ji.com/magnetic_receiving_loops.htm
73,
Dale W4OP
gravity
> >>
> >> If so, it would necessitate outdoor mounting.
some of us have vaulted ceilings, you insensitive clod.
Count Gravity
Steve
Dale Parfitt wrote:
>
> Please, someone share with the group why a shielded loop is less prone to
> noise p/u than other antennas- other than the fact that if done properly, it
> should have 2 deep nulls and thus be able to be rotated to place a single
> noise source in one of the nulls.
>
> I have a homebrew 7' shielded loop- with a broadband amp just like the
> Wellbrook. It is no less noisy than my classic L-C loop other than the fact
> that the 2 nulls appear to be a tad deeper.
>
> To dispell the black magic:
> http://www.w8ji.com/magnetic_receiving_loops.htm
>
> 73,
> Dale W4OP
I'm prepared to believe that it's not the loop design per se that
explains the quietness of the Wellbrooks. I imagine the amplifiers
employed are very quiet, so maybe that's the key? I don't know and I
won't pretend to have the answer.
Interestingly, earlier today I read that the designer of the
PA0RDT-Mini-Whip designed it PRECISELY because he was not able to make
an active magnetic loop antenna that was QUIET enough for NDB hunting
in urban areas. When I read this I was struck by the fact that it
contradicts conventional wisdom.
Steve
RHF
For AM/MW Radio Reception rotating the Loop
would be great for :
* Peaking the Signal over the Background Noise
-or-
* Nulling a Noise Source to Hear a Signal.
Then repeating the Process up-and-down the
AM/MW Radio Band as you Band Scan.
However - Above 5 MHz the directivity of most Loop
Antennas is diminished and the Process for me has
been to first Null the Noise Source(s) with the Loop
Antenna {Fixing the Loop in one position} and then
Band Scanning from 5 MHz to 30 MHz.
Note - This works well when the Loop Antenna is
located out-side the House 15-30-45 Feet away.
-If- Your Loop Antenna is in-doors then you may
find that different Point Noise Sources are coming
from different locations {Directions} within the House.
So now when you Band Scan from 5 MHz to 30 MHz :
You find that you have to re-position the Loop to Null
a Noise Source that is a problem on that frequency.
Don't have a WellBrook Loop Antenna so I can not
say if it is that much better then any other Loop.
- - - But one of these days . . . who knows ;-)
just my two cents worth ~ RHF
.
.
. .
cuh...@webtv.net
what makes your hard head so harrddd,,,,,,,? Buck Privates movie is on
Radio tv now.
cuhulin
cuh...@webtv.net
Them tree cutters will be here in the morning at 9:00 AM.I need to
remember to drop a film cartridge in my Kodak FX 600 whatever it is
camera and take some before and after photos to snail mail to that
married Irish woman wayyyyyy over yonder across the big pond.(seeee,I am
smart,I keep all my married and divorced galfriends lonnnnnngggggg
distance) Then I will phone the Garden Mama www.gardenmama.com
www.supertalkms.com about some fast growing shade trees.
cuhulin,the auld deep South,Mississippi
Dale Parfitt
>
> Dale Parfitt wrote:
>>
>> Please, someone share with the group why a shielded loop is less prone to
>> noise p/u than other antennas- other than the fact that if done properly,
>> it
>> should have 2 deep nulls and thus be able to be rotated to place a single
>> noise source in one of the nulls.
>>
>> I have a homebrew 7' shielded loop- with a broadband amp just like the
>> Wellbrook. It is no less noisy than my classic L-C loop other than the
>> fact
>> that the 2 nulls appear to be a tad deeper.
>>
>> To dispell the black magic:
>> http://www.w8ji.com/magnetic_receiving_loops.htm
>>
>> 73,
>> Dale W4OP
>
> I'm prepared to believe that it's not the loop design per se that
> explains the quietness of the Wellbrooks. I imagine the amplifiers
> employed are very quiet, so maybe that's the key? I don't know and I
> won't pretend to have the answer.
>
>of the receiver front end. You will always hear an increase in noise when
>you connect your antenna- so quiet amps offer no benefits.
Dale W4OP
RHF
When you have 'consider' the Possible
and it will not provide the Right Answer.
Then Consider the Impossible - What Works - WORKS !
yes it is that simple - iane ~ RHF
.
.
. .
RHF
- - - Dale W4OP
*
Dale [W4OP],
All things being relative many Amplifiers in consumer
grade Active Antenna for Shortwave are Noiser then the
Atmospheric Noise and the Receivers own front end.
I have often wondered why Active Antenna designs
did not incorporate a smaller Noise "Sense" Antenna
that would be intergrated into the Signal processing
path at the Antenna Element to cancel out most of
the Local Noise.
Lets say a One Meter (314cm) Loop Antenna terminating
at a Box at the bottom with the Broad-Band Amplifier in it.
Add a small thin 31cm Vertical Whip "Sense" Antenna
coming out of the Top of the Box. This "Sense" Antenna
would be 1/10th the Size of the One Meter Loop.
* The larger Main Loop Antenna would be a
Directional distant Signal Seeker.
* The smaller "Sense" Antenna would be
Omni-Directional local Noise Collector.
* * Maybe allow the user to vary the Mixing of
the larger Main Loop Antenna and the smaller
"Sense" Antenna in the Radio Shack.
Sort of like the Timewave ANC-4 Noise Canceller
and MFJ-1026 Noise Cancelling Signal Enhancer
-but- their "Sense" Antennas are in the Radio Shack
along with the other Radio Gear; and this "Sense"
Antenna would be at the Main Loop Antenna itself.
http://www.universal-radio.com/catalog/preamps/0094.html
http://www.universal-radio.com/catalog/preamps/3541.html
think and wondering - iane ~ RHF
.
.
. .
Ron Hardin
>
> "Steve" <sdan...@speakeasy.net> wrote in message
> news:1151268322....@p79g2000cwp.googlegroups.com..
> >
All loops, no matter how shoddily constructed, have two perfect nulls, infinitely
deep. (All small antennas have the same pattern, another way to say it.)
But there's an electric field null and a magnetic field null.
A loop works mostly on the magnetic field.
But it picks up an electric field, and the null for the electric field is not
anywhere near in the same place as for the magnetic field.
As a result, at the magnetic field null you hear not nothing, but the electric
field pickup of the station you want to null.
You can't ``correct'' this, because the electric field is at 90 degrees phase
to the magnetic one, by simply re-aiming a little bit. The two fields can't
be used to cancel each other unless you use phase shifters of some kind.
A loop that's geometrically well laid out will have minimal electric field pickup,
and that's how you get deep nulls from a well designed loop. The depth of the
null is the strength of the electric field pickup.
I doubt, incidentally, that the size of the loop matters much. The N in the S/N
that you're competing with is the internal noise of the receiver. The propagating
noise goes up just like the propagating signal and so is the same S/N for any size
loop.
Thus a good receiver can't use a really big loop usefully, beyond what it does
with a small loop.
I have a couple ALA 1530's in a phased array (combined in an ANC-4); and can
report that their S/N isn't as good as a Dymek McKay DA100E active whip, especially
at higher frequencies. But the built-in pattern of the loop is incredibly handy.
I'm in a pretty noise-quiet location as well.
--
Ron Hardin
rhha...@mindspring.com
On the internet, nobody knows you're a jerk.
Steve
Ron Hardin wrote:
>
> I doubt, incidentally, that the size of the loop matters much. The N in the S/N
> that you're competing with is the internal noise of the receiver. The propagating
> noise goes up just like the propagating signal and so is the same S/N for any size
> loop.
>
> Thus a good receiver can't use a really big loop usefully, beyond what it does
> with a small loop.
ll.
Not sure I follow you here. If I understand you correctly, you're
reasoning that you can't hear anything on a large aperture loop that
you can't hear on a small loop because they have the same S/N. But it
seems like you could run this same line of reasoning on random wire
antennas to reach the conclusion that you can't hear anything on a
100ft random wire that you can't hear on a 15ft random wire. Maybe I'm
missing something, but this doesn't make much sense to me. Why would
loops, unlike other kinds of antennas, fail to benefit from more signal
gathering capability?
Steve
Ron Hardin
> Not sure I follow you here. If I understand you correctly, you're
> reasoning that you can't hear anything on a large aperture loop that
> you can't hear on a small loop because they have the same S/N. But it
> seems like you could run this same line of reasoning on random wire
> antennas to reach the conclusion that you can't hear anything on a
> 100ft random wire that you can't hear on a 15ft random wire. Maybe I'm
> missing something, but this doesn't make much sense to me. Why would
> loops, unlike other kinds of antennas, fail to benefit from more signal
> gathering capability?
>
> Steve
It's true of random wires as well. Noise that's propagating is picked up
in proportion to Signal that's propagating, so the ratio is the same regardless
how much of it you gather.
What varies is the energy of that relative to the internal noise of the
receiver.
Once you're above the receiver's internal noise, more gathering doesn't help.
Thus better receivers fail to benefit where worse receivers do, from larger
antennas.
This applies to small antennas - ie without forward gain, having the standard
double-null pattern, such as you get from a small loop or whip. If you
have forward gain, you do in fact increase propagating signal relative to
propagating noise, by cutting out noise from at least directions that the
signal doesn't lie in.
cuh...@webtv.net
seventy feet tall Pecan tree in my front yard gone.I haven't let her
check out the back yard yet,with that almost seventy feet tall Pecan
tree gone.She just now threw up her front feet and went back to
sleep,sleeping on her back on her couch.
cuhulin
Brian Hill
I have a DX-1 Pro MkII that I think is great. It cost a lot but it's muti
directional and by the time you install the Wellbrook and rotor etc.. you'll
have probably spent more $s How quite is the Wellbrook?
--
Regards
B.H.
Souther, MN USA
Radios- R-5000, NRD525,SP-600,SX-28,Eton E1
Brian's Radio Universe
http://webpages.charter.net/brianhill/500.htm
Brian's Basement
http://webpages.charter.net/brianhill/6.htm
Remove your HAT to reply directly
briane...@charter.net
Steve
Ron Hardin wrote:
> It's true of random wires as well. Noise that's propagating is picked up
> in proportion to Signal that's propagating, so the ratio is the same regardless
> how much of it you gather.
>
> What varies is the energy of that relative to the internal noise of the
> receiver.
>
> Once you're above the receiver's internal noise, more gathering doesn't help.
>
> Thus better receivers fail to benefit where worse receivers do, from larger
> antennas.
> --
> Ron Hardin
> rhha...@mindspring.com
>
> On the internet, nobody knows you're a jerk.
What you're saying makes sense, and in another thread people have been
talking about the PA0RDT Mini-Whip, which, assuming it does what
everyone says, seems to demonstrate that small antennas can be just as
effective as much larger ones. Still, I have the sense that something
important is being left out. If I'm listening to AFN on 7811 with a
modest 20 ft wire and then switch over to a 100 ft wire, it does not
seem as though the 100 ft wire allows me to hear exactly what I was
hearing on the 20 ft wire, only at higher volume.
I always figured that, because most of the noise that plagues us is
local, a longer wire would have a greater "reach"---i.e., it would be
able to gather a greater proportion of signal in addition to all of the
local noise that you'd hear on a wire of *any* length. Another way to
put it: I'd have thought that what you can hear via antennas of
different sizes is analogous to what you can see through telescopes of
different sizes. Because of atmospheric distortion, there's a limit to
what you can resolve using an earthbound telescope, no matter what it's
size (that's why we put telescopes into orbit). There's a ratio of
light to atmospheric distortion that just can't be overcome...building
bigger telescopes won't help. However, this is consistent with the fact
that the big reflector on Mt. Palomar can make out much more detail on
the moon's surface than the telescope in my backyard. And the only
explanation for this is the fact that the big reflector is taking in
more light from the moon.
But enough of my armchair speculation. I'll leave it to you experts out
there to decide (assuming you're still awake)!
Steve
Caveat Lector
--
CL -- I doubt, therefore I might be !
<cuh...@webtv.net> wrote in message
news:12575-44A...@storefull-3253.bay.webtv.net...
Telamon
"Dale Parfitt" <p...@parelectronics.com> wrote:
I really hate it when people make references like "black magic" and "old
wives tales" and the like to make a point. It's a real turn off to use
rhetorical device in a technical document. Like the page states
far field effects are the same between dipoles and loop antennas.
There is no claim of far field noise improvement of a shielded loop
antenna over a dipole. The issue is unwanted local noise pickup. A
balanced shielded loop is the least sensitive to the inductive fields of
local noise sources as a function of distance. Most local noise sources
to antenna coupling is from common mode voltage field induction.
The page you reference is not correct in some instances but not grossly
incorrect. Shielded loops have lower impedance than unshielded and
couple to local noise sources the least of any antennas discussed and
this difference depends on the loop size where a larger electrical size
will have a larger difference in field impedance. The author makes
general statements about loops and then only discusses small loops.
Either loop design shielded or otherwise generate smaller currents from
local inductive noise sources than a dipole. The dipole will pick up
less noise from local noise sources than an unbalanced Marconi type
antenna. Balanced shielded loop designs will reject electric fields
better and have a lower impedance than unshielded. It's not easy to
tell from the chart scale but the right hand side should be ~ 377 ohms
for either antenna type.
Keep in mind that there are differences in how a loop antenna functions
based on electrical length. Electrically small antennas are the current
type and the larger loops are affected by both E and M fields.
--
Telamon
Ventura, California
Telamon
"Dale Parfitt" <p...@parelectronics.com> wrote:
> "Steve" <sdan...@speakeasy.net> wrote in message
> news:1151285587....@u72g2000cwu.googlegroups.com...
> >
> > Dale Parfitt wrote:
> >>
> >> Please, someone share with the group why a shielded loop is less prone to
> >> noise p/u than other antennas- other than the fact that if done properly,
> >> it
> >> should have 2 deep nulls and thus be able to be rotated to place a single
> >> noise source in one of the nulls.
> >>
> >> I have a homebrew 7' shielded loop- with a broadband amp just like the
> >> Wellbrook. It is no less noisy than my classic L-C loop other than the
> >> fact
> >> that the 2 nulls appear to be a tad deeper.
> >>
> >> To dispell the black magic:
> >> http://www.w8ji.com/magnetic_receiving_loops.htm
> >>
> >
> > I'm prepared to believe that it's not the loop design per se that
> > explains the quietness of the Wellbrooks. I imagine the amplifiers
> > employed are very quiet, so maybe that's the key? I don't know and I
> > won't pretend to have the answer.
> >
> >Noise floor at LF-->HF is limited by atmospheric noise not the noise figure
> >of the receiver front end. You will always hear an increase in noise when
> >you connect your antenna- so quiet amps offer no benefits.
You need an amplifier for electrically small antennas with a noise floor
below that of atmospheric noise or it will affect weak signals that you
can hear. The amplifier design needs to provide an appropriate level of
amplification at a good enough noise figure to provide for weak signal
performance. At low frequencies atmospheric noise is higher making this
an easier thing to achieve.
--
Telamon
Ventura, California
Telamon
Ron Hardin <rhha...@mindspring.com> wrote:
Good follow up post. I would add that smaller loops generally have
better defined deep nulls over a larger loop.
--
Telamon
Ventura, California
gravity
> reasoning that you can't hear anything on a large aperture loop that
> you can't hear on a small loop because they have the same S/N. But it
> seems like you could run this same line of reasoning on random wire
> antennas to reach the conclusion that you can't hear anything on a
> 100ft random wire that you can't hear on a 15ft random wire. Maybe I'm
> missing something, but this doesn't make much sense to me. Why would
> loops, unlike other kinds of antennas, fail to benefit from more signal
> gathering capability?
depends on the type of loop. some MW dxers use loops like the small
Palomar. you can use tilt and rotation to get nulls that are hard on long
wires.
a 15 foot long wire has terrible radiation resistance on 80 meters. an 100
foot long wire will start having lobes on 10 meters.
personally i think a high rotatable dipole would be good.
Gravity
gravity
> reasoning that you can't hear anything on a large aperture loop that
> you can't hear on a small loop because they have the same S/N. But it
> seems like you could run this same line of reasoning on random wire
> antennas to reach the conclusion that you can't hear anything on a
> 100ft random wire that you can't hear on a 15ft random wire. Maybe I'm
> missing something, but this doesn't make much sense to me. Why would
> loops, unlike other kinds of antennas, fail to benefit from more signal
> gathering capability?
>
> Steve
>
a Beverage doesn't pick up much signal, but it's S/N ratio is often better
than verticals and inverted vees. depends on the path. in addition, it has
nulls.
Gravity
dxAce
gravity wrote:
A Beverage has gain and picks up more signal as its length increases (in the
direction it's running). They DO pick up a lot more signal.
dxAce
Michigan
USA
Dale Parfitt
"dxAce" <dx...@milestones.com> wrote in message
news:44A04A8B...@milestones.com...
Perhaps, more importantly, because they are highly directive, they pick up
less noise assuming the noise is well distributed in the azimuth.
Dale W4OP
RHF
Shortwave Listening {Receive Only} Antennas
- Away is better then Up ! Or Is It ?
Where you are better off {usually} with a longer
Antenna + Ground + Feed-in-Line System and
Local Noise is :
Very High Signal & Very High Noise Antenna Design :
A 10 Foot Coax Cable feed-in-line up the side of
the House to the Peak of the Roof that is coupled
to a 100 Foot Horizontal Antenna Element and
using the Radio Shack's Ground.
- Why - The First 50 Feet of the Antenna is close
to the House and Noise and the other 50 Feet
is relatively Noise Free.
Very High Signal & High Noise Antenna Design :
A 25 Foot Coax Cable feed-in-line going out away
from the House 15 Feet that is coupled via a
Matching Transformer to a 15V/85H Foot Inverted
"L" Antenna Element and using the Radio Shack's
Ground.
- Why - The First 50 Feet of the Antenna is close
to the House and Noise and the other 50 Feet
is relatively Noise Free.
Moderate Signal & Less Noise Antenna Design :
A 50 Foot Coax Cable feed-in-line going out away
from the House 40 Feet that is coupled via a
Matching Transformer to a 15V/60H Foot Inverted
"L" Antenna Element and using a Matching
Transformer and a remotely located Ground Rod
at the base of the Antenna.
- Why - The First 25 Feet of the Antenna is close
to the House and Noise and the other 50 Feet
is relatively Noise Free.
Moderate Signal & Very Low Noise Antenna Design :
A 110 Foot Coax Cable feed-in-line going out away
from the House with 100 Feet Buried that is coupled
to an a Far-End-Fed 15V/50H Foot Inverted "L" Antenna
Element and using a Matching Transformer and a
remotely located Ground Rod at the base of the Antenna.
- Why - The Entire 65 Feet of the Antenna is away
from the House by 50 Feet and is relatively Noise Free.
The-Bottom-Line - Use the Available Space to position
the Wire Antenna Element away from Sources of Noise
and let the Signal Levels take care of themselves when
the Length of the Wire Antenna Element is beyond
35 Feet.
at least that is the way i see it - iane ~ RHF
.
Shortwave Listener Antennas => http://tinyurl.com/ogvcf
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/
SWL Antenna Group => http://tinyurl.com/ogvcf
.
The Shortwave Listener's Blessing :
SWL BLESSING => http://tinyurl.com/s2bjm
May You Never Tire of Listening to the Radio and Always
have Strong Signals and Noise Free Reception ~ RHF {ibid}
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/message/9233
.
|
|
|
/ \
.......!.......
mumbl...@gmail.com
This whole debate is nuts. I have a 150 foot longwire behind my house.
It allows me to hear stations that are nowhere to be found using a 16
foot reel antenna. Period! Any theory that denies this is bunkum.
dxAce
Dale Parfitt wrote:
Yes indeed.
dxAce
Michigan
USA
RHF
Yes once you get past the first 64 Feet of the 150 Foot
Long Wire the Signals have a lot less Noise from the
last 65-150 Feet : Then the 16 Foot Reel Antenna -
Relative to your House being the primary Source of
Local Noise.
The Better Long Wire Antenna :
You may find that you would get even better Radio
Reception with a 50 Foot Coax Cable out to 50 Feet
and a 100 Foot Wire Antenna Element from 51-150
Feet.
Add - A MatchingTransformer between the Wire
Antenna Element and the Coax Cable.
Install - A remote Ground Rod at the 50 Foot point
where the MatchingTransformer, Wire Antenna
Element and the Coax Cable all come together.
Plus - Get the Wire Antenna Element Up-in-the-Air
about 15-25 Feet - So that it is not a Ground
Tripping Hazard or a ClothesLine type Hazard.
Rig - The Wire Antenna Element as a Short
Vertical-Up-Leg with a Long Horizontal-Out-Arm
- - - Lets call it an Inverted "L" {Shape} Antenna :o)
something to think about - iane ~ RHF
.
Shortwave Listener Antennas => http://tinyurl.com/ogvcf
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/
SWL Antenna Group => http://tinyurl.com/ogvcf
.
The Shortwave Listener's Blessing :
SWL BLESSING => http://tinyurl.com/s2bjm
May You Never Tire of Listening to the Radio and Always
have Strong Signals and Noise Free Reception ~ RHF {ibid}
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/message/9233
.
|
|
|
/ \
.......!.......
mumbl...@gmail.com
RHF wrote:
> Mumbler,
>
> Yes once you get past the first 64 Feet of the 150 Foot
> Long Wire the Signals have a lot less Noise from the
> last 65-150 Feet : Then the 16 Foot Reel Antenna -
> Relative to your House being the primary Source of
> Local Noise.
>
Actually, if I take both antennas into the deep woods, I will still
hear stations on the 150 foot wire that are not detectable on the reel
antenna. Not as many, but some. And I won't hear any stations on the
reel that I couldn't hear better on the longer wire. Haven't you guys
ever tried this yourselves?
Dale Parfitt
<mumbl...@gmail.com> wrote in message
news:1151408718.2...@i40g2000cwc.googlegroups.com...
will be surprised how well it will p/u HF (in the woods, away from noise).
Dale W4OP
Greg
"Dale Parfitt" <p...@parelectronics.com> wrote:
Dale, excuse my ignorance, but what is a simple Z converter?
Greg
Michael Lawson
"Greg" <gfi...@yourpantstampabay.rr.com> wrote in message
news:gfight-448186....@news-server2.tampabay.rr.com...
Impedance converter, called by some an un:un or
a 9:1 (or 10:1) converter.
--Mike L.
cuh...@webtv.net
them tick?
cuhulin
cuh...@webtv.net
cuhulin
RHF
stuck in the Deep Woods :o) ~ RHF
.
.
. .
Dale Parfitt
>> Probably not a fair test- add a simple Z converter to the 16' wire and
you
>> will be surprised how well it will p/u HF (in the woods, away from
>> noise).
>>
>> Dale W4OP
>
> Dale, excuse my ignorance, but what is a simple Z converter?
>
> Greg
Hi Greg,
Because a short antenna has a very hi Z (almost entirely capacitive
reactive) it presents a poor match to 50 Ohm input receivers.
Either a hi turns ratio transformer or simple FET input preamp will do the
job nicely.
The Lowe HF-150 has a "whip preamp" built in- this is a Z transformer- and
other receivers may have the same.
The Lowe 20" whip does an absolutely outstanding job when combined with the
whip preamp.
The combination of the 2 are essentially an active antenna.
73,
Dale W4OP
David
Greg
"Dale Parfitt" <p...@parelectronics.com> wrote:
Got it. Thanks Dale, and Michael.
Greg
Joe Analssandrini
No one other than Andy Ikin, the designer and manufacturer, actually
knows what is inside the "electronics" portion of the Wellbrook ALA
330S and/or any of the other Wellbrook loop antennas. The electronics
are embedded in a substance that destroys the innards if someone
attempts to "reverse-engineer" them. I don't blame Andy Ikin for doing
this. There is obviously a very small market for such antennas and he
put a lot of his time and his effort in designing the antenna and the
circuitry so why should he make it "easy" for someone to copy what he
did?
Frankly, though his antennas appear relatively costly, they are far
less expensive than the radios for which they are intended. Remember
that the "best" antenna is really the cheapest - a LONG wire, but this
is wholly impractical for most people and, even if one has the physical
space to erect one of these, local electrical noise may overwhelm the
signals the antenna picks up. Sure a Beverage is a low-noise passive
antenna, but, for OPTIMUM results, say, on 49 meters, the antenna
should be 49 meters long - 160 feet. While that's not too bad, figure
out what it would be for MW! (At least 300 feet!) Most Beverages are
even longer (MUCH longer) and, really, few of us have the space on our
properties. And Beverages are highly directional; how are you going to
rotate one when you want to listen to a particular station and/or null
another one? Rotate a 150 - 1000-foot antenna? Forget it! So we're left
with passive wire antennas (longwires, dipoles, slopers, etc.) which
may prove unsatisfactory due to the "noise" issue, or we buy a
Wellbrook!
Wellbrooks are also very low-noise (being loops, they are sensitive to
the magnetic portion of the radio signal while being less sensitive to
the electrical portion, where the noise is. And they are also highly
directional - but it's easy to rotate a 3-foot loop! Just mount it on
an inexpensive Radio Shack TV-antenna rotator and turn the knob when
necessary.That' what I've done. Also, since the antenna can be mounted
low, such as on a fence-post or deck railing, you can even rotate it by
hand.
And they have Andy Ikin's proprietary electronics.
Due to the great increase in the population in my town-house community
over the years, with computers, fluorescent lights, high-pressure
sodium and/or mercury arc-vapor lights, Christmas lights, etc., etc.,
etc., I would have had to abandon the hobby had I not, being desperate,
tried the Wellbrook ALA 330S based on its review in PASSPORT. Let me
tell you - they are right on the mark. This antenna is, for me, almost
unbelievable - really a "miracle." I bought it for use with my AOR
AR7030 Plus; I tried it also with my Grundig Satellit 800 and it made
such a difference with that radio that I bought a SECOND Wellbrook ALA
330S! (You can even use it with a Sony ICF-SW7600GR - I've done it -
though buying a Wellbrook specifically for a portable radio is a bit of
"overkill," in my estimation.)
I'm certainly not telling you or anyone else how to spend your money.
It may be that you don't have the particular problems at your location
which the Wellbrook can overcome (limited space, lots of local
electrical noise) and even the summertime increase in atmospheric noise
may not bother you, depending on your listening habits - these are the
conditions in which the Wellbrook(s) excel. Or the antenna may be
beyond your financial abilities at the present time. I can only tell
you my own experience and I will suggest that, if one has the major
problems at his/her location such that I have described, and that
person sincerely wants to minimize them so as to be able to hear
shortwave broadcasts with a "top" receiver (tube or transistor), then
the Wellbrook loop antennas can offer a level of performance
unavailable with any other antenna, at least in my personal experience.
Best,
Joe
cuh...@webtv.net
interested in trying to reverse engineer them.I wouldn't know what I was
doing anyway.I was only wondering what makes them so good.Wouldn't be
any trick for me to reverse my non working Tiny Tenna though.All of the
parts are right there in plain sight.
cuhulin
mi...@sushi.com
cuh...@webtv.net wrote:
> Anybody ever dug into the guts of a Wellbrook antenna? Caledonia,just
> what makes your hard head so harrddd,,,,,,,? Buck Privates movie is on
> Radio tv now.
> cuhulin
The amplifier is potted to er um make it really really weather-proof.
Oh, that does make it hard to reverse engineer too. ;-)
mi...@sushi.com
Steve wrote:
> I fired off a message to Andy Ikin asking him whether the ALA 100 would
> have a real edge over the 330S on SW, given its larger aperture. He
> replied that he has an ALA 100 attached to a 25m wire Delta loop. This
> antenna at HF gives approx. 17-20dB higher gain than the ALA330S and
> the ALA1530. That's pretty impressive.
>
> Steve
If you have a dialog going with the designer, see if he will tell you
what was changed when they went from positive ground to negative ground
on the amps.
Is there some advantage to a delta loop over a square loop?
I have a loop frame that allows for single turn up to 4 turns on an
8ft diagonal square. This uses the ALA-100 in the middle, so you have
two wires that have to be tilted at they need to reach the center of
the loop.
This is mostly a prototyping system to see how many turns you can use
without losing the top end (i.e. around 30Mhz). If the loop windings
are too close together, you lose gain at high frequencies, probably due
to capacitance between the wires. I haven't settled on a design yet,
but 3 turns spaced out about 8 inches does a good job. With that
antenna, some local BCB AM forces the 7030 to turn on it's attenuator.
It has enough gain to get AFN out of Hi at noon from the left coast. [I
wanted to hear Ed Schultz on AFN, just to see if the DOD really is
providing equal time.]
Greg
mi...@sushi.com wrote:
I suspect there are people on this newsgroup that get potted to be
weather-proof. Not that there's anything wrong with that...
Greg
Mark Zenier
One example is the Grove Mini-tuner (Tun3). It's pretty useless on HF
with reasonable length random wire, but it makes a OK indoor antenna
with about 10-15 feet of wire. Good during thunderstorm weather.
Or for getting anything at all on longwaves on a 50 foot wire.
Mark Zenier mze...@eskimo.com
Googleproofaddress(account:mzenier provider:eskimo domain:com)
Steve
One of these days I might actually break down and buy the ALA 100. The
fact that it gives you the freedom to design your own loop is a huge
plus in my view. When I bought my ALA 330S, I was so short on space
that experimenting with loops was pretty much out of the question. The
330S's small size was a big selling point. Now that my circumstances
have changed, the ALA 100 is starting to look good. Of course, I could
also try one of those mini-whips discussed recently, if only because
the purchase price comes to less than $60.
cuh...@webtv.net
the time.She isn't studying any fire plugs.
Cell Phones Cook An Egg. www.rense.com
Set up an egg in a porcelain cup and two cell phones on either side of
the egg.Phone both cell phones and keep them going.About 25 minutes
later,the egg starts getting hot.
Everywhere I go when I go out shopping and even my neighbors constantly
have those cell phones (egg cookers) glued to their ears.Imagaine what
that is doing to those dummies heads!
Red Fox,,,, ,boy!,now what did I tell you about that cell phone!
I had a cell phone about seven years ago,I almost never used it or took
it anywhere with me.It was only a novelty thingy for me.I am glad I let
my two years cell phone contract with Bell South drop.
cuhulin
cuh...@webtv.net
has it backwards.
cuhulin
mi...@sushi.com
I'm sure you think you are entertaining, but really I'm getting tired
of your nonsense.
For those who are really interested, the older generation Wellbrooks
used a positive ground, while the later generation uses a negative
ground. It may be that the first generation circuitry used jfets, while
the second generation use SiGe.
mi...@sushi.com
Flat against the window puts the null to the glass. No wonder it didn't
work well.
gravity
"Joe Analssandrini" <analssa...@yahoo.com> wrote in message
news:1151459256....@y41g2000cwy.googlegroups.com...
>Remember
> that the "best" antenna is really the cheapest - a LONG wire, but this
> is wholly impractical for most people and, even if one has the physical
> space to erect one of these, local electrical noise may overwhelm the
> signals the antenna picks up.
i would say beams and logs are better than long wires. of course, high gain
rhombics are nice.
> Sure a Beverage is a low-noise passive
> antenna, but, for OPTIMUM results, say, on 49 meters, the antenna
> should be 49 meters long - 160 feet.
well, 2 waves is a typical beverage. that's about 1000 feet on 160 meters.
optimally, you would have two spaced Beverages.
> While that's not too bad, figure
> out what it would be for MW! (At least 300 feet!)
>Most Beverages are
> even longer (MUCH longer) and, really, few of us have the space on our
> properties. And Beverages are highly directional; how are you going to
> rotate one when you want to listen to a particular station and/or null
> another one?
most people who use Beverages aim one at Europe and other areas of interest.
you can't rotate them, but sometimes you can steer the null.
> Rotate a 150 - 1000-foot antenna? Forget it! So we're left
> with passive wire antennas (longwires, dipoles, slopers, etc.) which
> may prove unsatisfactory due to the "noise" issue, or we buy a
> Wellbrook!
log periodics are big on 49 meters, but mechanically possible.
Gravity
gravity
> the magnetic portion of the radio signal while being less sensitive to
> the electrical portion
that's ONLY true in the nearfield.
Gravity
Joe Analssandrini
Best,
Joe
rne...@vcn.bc.ca
I just received my second ALA100.
One was not enough!
Fabulous product.
/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/
www.dxer.ca Canada's original radio resource
Co-creator of the DX Podcast
\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\
cuh...@webtv.net
cuhulin
mi...@sushi.com
See if the polarity has changed. If it has, use some caution that you
don't accidentally short the bnc connectors between at the amplifiers
together.
My ALA 100 is serial number 16.
Telamon
"gravity" <gravity...@yahoo.com> wrote:
The Wellbrook electrically small shielded loops are only sensitive to
the magnetic field component near or far field.
Far field signals and noise are EM waves where that essentially have the
same energy in the electric and magnetic fields and that's why signal to
noise on the far fields is not improved over electric field sensitive
antennas like dipoles.
Nearby noise sources tend to have their electric induction fields spread
out farther than the magnetic induction fields so generally a small loop
will pick up less local noise than a small dipole.
--
Telamon
Ventura, California
RHF
Yes - The Grove Mini-Tuner "TUN3" does make a good
Antenna Turner for those bad weather days with a
relatively 'short' indoor Antenna.
A Mini-Slinky {Metal Spring Thingee} Dipole Antenna
12-Foot-to-the-side (24 Ft. T2T) that is set-up in the
Corner of a Room works well with the Grove TUN3
Mini-Tuner.
SOURCE - 3 Pack Metal Springs (For Ages 3 and Up)
http://groups.google.com/group/rec.radio.shortwave/msg/6b702fa6fdb773fb
Simple-to-Make : Dual Slinky Dipole Antenna
http://groups.google.com/group/rec.radio.shortwave/msg/a30aacb8e4723daa
Doing the Math - 3 Pack Metal Springs
http://groups.google.com/group/rec.radio.shortwave/msg/b53dac9f07fa3159
jm2cw - iane ~ RHF
.
.
. .
Ron Hardin
> If you have a dialog going with the designer, see if he will tell you
> what was changed when they went from positive ground to negative ground
> on the amps.
There have always been two versions. I special-ordered a neg ground (the UK
version) for the US so that I have only neg ground devices on my radios.
Apparently the wall wart for the US puts out pos ground and so the antenna amp
is wired to expect that, unless you say otherwise and use your own 12 source.
Only the power plug is affected. All versions use neg ground on the coax going
to the loop.
It would more properly be called positive tip in the power plug, since neither
choice is really a ground at that point; it's just a reversal of the wiring of
the plug, which I didn't want floating around in the rat's nest of wires I
maintain.
--
Ron Hardin
rhha...@mindspring.com
On the internet, nobody knows you're a jerk.
mi...@sushi.com
I measured the potential from the ground at the radio to the hot on the
coax going to the amp, and there is no potential difference. I need to
dig up my 12V positive ground cigarette lighter adapter and check the
amp to the frame. I could have sworn I popped a fuse by having the coax
hit the frame.
The Shortwave Shop in the UK didn't give me an option on the polarity.
I noticed this photo has the positive ground:
http://www.astrosurf.com/lombry/Radio/ala-1530-interface.jpg
Also, the diagrams on the website used to have postive ground, but now
are negative ground.
I guess what I'm leading to is I don't think there was an option, but
rather they changed the design and perhaps gave you a choice in which
version to buy.
cuh...@webtv.net
wire with light bulb sockets hanging down from the ceilings.Big
fireplace.My grandaddy and his brother built that house back in the
1910's or before.It was the first house in Carthage to have
electricity.Had indoor pumbing too with tongue and groove wainscoting on
the walls.They don't make them like that anymore.Nowdays the inside
walls are junk you can put your hand through if you lean on them too
much.
cuhulin
RHF
Ron Hardin wrote:
> mi...@sushi.com wrote:
> > If you have a dialog going with the designer, see if he will tell you
> > what was changed when they went from positive ground to negative ground
> > on the amps.
>
> There have always been two versions.
I special-ordered a neg ground (the UK version) for the US
so that I have only neg ground devices on my radios.
RH - A Wise Choice ~ RHF
Especially if you ever intend going Mobile.
Ron Hardin
I got mine long ago, from wellbrook but via the shortwave shop as far as
the credit card went. No wall wart was included (the US wall wart being
the positive ground culprit, and me having no use for the neg gnd UK 220 wall wart),
and I simply used my own existing 12v power supply, which also powers 30 other
devices, with neg ground.
I think the whole thing was driven by the availability to wellbrook of US wall
warts that they considered suitable, there being no other advantage to positive
ground.
And as I say, it isn't really positive ground if you use the wall wart, just
a matter of which way the plug is wired, neither side being ground at all in fact.
You don't want mixed polarity plugs roaming around, though.
cuh...@webtv.net
grounded.
(I have known that since the early 1950's) Pecan trees? Pecan trees are
ground grounded.At least those two Pecan tree stumps that are left over
from last Monday are.The one in my front yard is just the perfect height
for me to sit on,which I do,do so once in a while,while doggy is doing
her ''business'' in the front yard.
cuhulin
mi...@sushi.com
Yeah, this is the one item that needs the special power cord for mobile
use. It's really a pain. What I do is put that cord in a zip lock bag
with the rest of the set-up. However, I had the cord (12V connector)
break in the field and had no spare. Had it been negative ground, I
would have plenty of spares.