开云体育

Hi JR,

Hmmm.....if i knew earlier the Kyle KOLR design would have a higher
noise floor, i would opt for your Pre-amp design which i choose not to
earlier as i thought Kyle's circuit looks more 'sophisticated'.....

nevertheless, i will also try out your Pre-amp and see what happens.....

oh...great, now i've to order a toroid for the transformer.....

best regards,

Alan Wong.




"jr_dakota" <SG2112@...>
Sent by: loopantennas@...
07/11/2007 08:04 AM
Please respond to loopantennas

To: loopantennas@...
cc:
Subject: [loopantennas] Re: Remote_Tuned_Loop By Portstevos


In the files section there is a file called Loop Circuit.rtf .... The
left schematic is what I used, I used a single varactor simply because
the signal levels are so small that it's really not necessary to do
the series/parallel thing with 4 of them (But you DO need them that
way to tune a whip or 'longwire' which will have voltage spikes from
noise not present in the magnetic field loop)

I don't use that preamp anymore but opted for a lower noise, higher
gain, more gain range low impedance RF amp shown in file
Lo_Imp_Loop_Preamp

The main drawback to my system (well for most people) is that you need
to run seperate wires for controlling the tuning, amp gain, and to
supply power but IMO this is the best way to go, feeding a coax so the
RF has to ride a DC voltage is almost always noisier than seperate
feeds for the DC voltages

My loop is made from a piece of 1/2" O.D. (Yes O.D. it's refrigeration
copper I get for free) soft copper tubing 10 foot long and mounted on
my roof with a cheap Channel Master rotor and I use a coax shielded
(balanced) pickup loop .... It'll be 3 years in September since I
mounted it and other than changing the preamp to the new style, it's
never been touched or had a problem ... The preamp has enough gain
that I can pickup up a lot of AM BCB stations even though the loop
itself only tunes down to ~5 Mhz ...

I'm interested to see what my bulletproof RF amplified untuned loop (
a Sickbrook clone with MY OWN ORIGINAL CIRCUITRY)) will compare to it

JR

The ONLY real advantage a Wellbrook (or any other amplifiied untuned
loop) has over a tuned loop is a wide range of operating frequencies
and a tuned loop has several advantages over an untuned loop as long
as you stay in the frequency range the loop is designed for, for
instance a tuned loop has some filtering capabilities not present in
any untuned loop, it also tends to have a more stable output impedence
making the preamp design easier to do effectively or not even having
to use a preamp in some cases

The down side is to tune from LF up to the upper end of the HF range
you need several tuned loops whereas one untuned loop will do the same
job **if** you have a well designed wideband RF preamp/impedance
converter to go with it

I'm working on an untuned amplified loop with a high IP2/IP3 preamp
but I don't get much done in the shop during the summer months and I
didn't get my antenna analyzer (AmQRP Antenna Analyst "AA-908"),
spectrum analyzer (KangaUS kit of Wes Hayward's design) and misc. gear
for IP2/IP3 testing done until late spring


--- In loopantennas@..., aimo ruoho <aimounto@...> wrote:

Would this new system be as good or even better than the very costly

(excessively expencive) Badbrook antennas?

If so, I for 1 would be very much interested to build 1 or more of

them!

Aimo

dldorrance <dldorrance@...> wrote:
Hi Alan,

In the files section there is a file called Loop Circuit.rtf .... The
left schematic is what I used, I used a single varactor simply because
the signal levels are so small that it's really not necessary to do
the series/parallel thing with 4 of them (But you DO need them that
way to tune a whip or 'longwire' which will have voltage spikes from
noise not present in the magnetic field loop)

I don't use that preamp anymore but opted for a lower noise, higher
gain, more gain range low impedance RF amp shown in file
Lo_Imp_Loop_Preamp

The main drawback to my system (well for most people) is that you need
to run seperate wires for controlling the tuning, amp gain, and to
supply power but IMO this is the best way to go, feeding a coax so the
RF has to ride a DC voltage is almost always noisier than seperate
feeds for the DC voltages

My loop is made from a piece of 1/2" O.D. (Yes O.D. it's refrigeration
copper I get for free) soft copper tubing 10 foot long and mounted on
my roof with a cheap Channel Master rotor and I use a coax shielded
(balanced) pickup loop .... It'll be 3 years in September since I
mounted it and other than changing the preamp to the new style, it's
never been touched or had a problem ... The preamp has enough gain
that I can pickup up a lot of AM BCB stations even though the loop
itself only tunes down to ~5 Mhz ...

I'm interested to see what my bulletproof RF amplified untuned loop (
a Sickbrook clone with MY OWN ORIGINAL CIRCUITRY)) will compare to it

JR

Would this new system be as good or even better than the very costly (excessively expencive) Badbrook antennas?
If so, I for 1 would be very much interested to build 1 or more of them!
Aimo

dldorrance <dldorrance@...> wrote:
Hi Alan,

You are not the only one who is confused.

I am at a disadvantage, as I am not able to read the text which
accompanies some of his diagrams (too small). However, looking at the
two amplifier diagrams, the schematic in Preamp2.jpg is to amplify the
signal coming out of a traditional small loop antenna, which contains
a main loop tuned with a traditional variable capacitor and a sense
loop. The preamplifier simply boosts the signal received by the sense
loop. It is situated between the sense loop and the transmission line
coax. It has no tuning function.

The other preamp, see Looppreamp1.jpg, attaches to the main loop in
place of the variable capacitor (I think). It contains back-to-back
varactor diodes, which replace the tuning capacitor and can tune the
main loop by altering the voltage applied to the varactor diodes.
With this setup no sense loop is needed.

Most of the amplified remotely tuned small loops I have seen use a
preamplifier as in looppreamp1.jpg, which is attached to the main loop
and works without a sense loop.

So you need to make some choices. First choice is to build a
traditional small loop with a variable capacitor and a sense loop.
There are literally hundreds of websites outlining this method. That
would give you a feel for how small loops work. Second, you could add
a preamp between the sense loop and the coax. See the diagram in
Preamp2.jpg. Third you could build a remotely tuned loop with
varactor diodes attached to a preamplifier (no need for a sense loop)
see Looppreamp1.jpg.

That is a rough outline. The details follow from what you want to
build. I hope this helps (and I hope I got it right).

Dave

--- In loopantennas@..., mwwong@... wrote:

Hi Dave,

please correct me if i'm wrong as i'm just a beginner in loop

antennas....

in summary, if i were to build a remote tuned loop based on Kyle KOLR
design, the tuning & preamp circuit board will be attached to the main
loop while i still need another smaller coupling loop (ie. as what
Portstevos
has illustrated in his phots) as a feedline into my receiver......

if this is so, do i need another preamp to be connected to the coupling
loop?

as alternative, could i just feed into my receiver from the main loop
without
the use of any coupling loop similar to the WL1030 design?....

please forgive if my above queries sounds a bit silly as i'm still
grasping around
on antennas designs....

best regards,

Alan Wong






"dldorrance" <dldorrance@...>
Sent by: loopantennas@...
07/07/2007 03:48 AM
Please respond to loopantennas

To: loopantennas@...
cc:
Subject: [loopantennas] Re: Remote_Tuned_Loop By

Portstevos

Hi Alan,

Please see inline responses.

Dave WA6YSO

--- In loopantennas@..., "alamdamai1" <mwwong@> wrote:

Hi,

I'm currently in the process of purchasing parts for fabricating the
loop that Portstevos had posted in the Files Section whereby i would
like to seek members further knowledge on the original Kyle KOLR
Remote-tuned Loop Pre-amp design....

May i enquire is the loop as indicated in Kyle's schematic is
referring to the main loop or the smaller coupling loop? (pls refer
to filename loopdiagram1 for the schematic....)

The pre-amp is placed on the main loop. The main loop (inductor) and
capacitor (here a varactor setup) forms a parallel resonant (tuned)
circuit. In a small loop, the coupling loop is half of a transformer,
converting the low impedance of the main loop (well under 1 ohm) up to
50 ohms, (the standard input for the radio) which achieves maximum
power transfer.

Reason being i would like to try out Kyle's design of using varactor
(tuning) diodes as a tuning capacitor for the main loop...

However, if the loop in the schematic is referring to the main loop,
then i'm a bit confused at which point in the Pre-amp circuit board
do i solder the coupling loop feedline for signal pre-amplification
before going out to the receiver.

No tuning loop is needed with the pre-amp. The output of the
amplifier (the emitter follower) is set for the maximum power
transfer to the receiver.

best regards,

Alan Wong

---------------------------------
We won't tell. Get more on shows you hate to love
(and love to hate): Yahoo! TV's Guilty Pleasures list.

Hi Alan,

You are not the only one who is confused.

I am at a disadvantage, as I am not able to read the text which
accompanies some of his diagrams (too small). However, looking at the
two amplifier diagrams, the schematic in Preamp2.jpg is to amplify the
signal coming out of a traditional small loop antenna, which contains
a main loop tuned with a traditional variable capacitor and a sense
loop. The preamplifier simply boosts the signal received by the sense
loop. It is situated between the sense loop and the transmission line
coax. It has no tuning function.

The other preamp, see Looppreamp1.jpg, attaches to the main loop in
place of the variable capacitor (I think). It contains back-to-back
varactor diodes, which replace the tuning capacitor and can tune the
main loop by altering the voltage applied to the varactor diodes.
With this setup no sense loop is needed.

Most of the amplified remotely tuned small loops I have seen use a
preamplifier as in looppreamp1.jpg, which is attached to the main loop
and works without a sense loop.

So you need to make some choices. First choice is to build a
traditional small loop with a variable capacitor and a sense loop.
There are literally hundreds of websites outlining this method. That
would give you a feel for how small loops work. Second, you could add
a preamp between the sense loop and the coax. See the diagram in
Preamp2.jpg. Third you could build a remotely tuned loop with
varactor diodes attached to a preamplifier (no need for a sense loop)
see Looppreamp1.jpg.

That is a rough outline. The details follow from what you want to
build. I hope this helps (and I hope I got it right).

Dave



--- In loopantennas@..., mwwong@... wrote:

Hi Dave,

please correct me if i'm wrong as i'm just a beginner in loop

antennas....

in summary, if i were to build a remote tuned loop based on Kyle KOLR
design, the tuning & preamp circuit board will be attached to the main
loop while i still need another smaller coupling loop (ie. as what
Portstevos
has illustrated in his phots) as a feedline into my receiver......

if this is so, do i need another preamp to be connected to the coupling
loop?

as alternative, could i just feed into my receiver from the main loop
without
the use of any coupling loop similar to the WL1030 design?....

please forgive if my above queries sounds a bit silly as i'm still
grasping around
on antennas designs....

best regards,

Alan Wong






"dldorrance" <dldorrance@...>
Sent by: loopantennas@...
07/07/2007 03:48 AM
Please respond to loopantennas

To: loopantennas@...
cc:
Subject: [loopantennas] Re: Remote_Tuned_Loop By

Portstevos

Hi Alan,

Please see inline responses.

Dave WA6YSO

--- In loopantennas@..., "alamdamai1" <mwwong@> wrote:

Hi,

I'm currently in the process of purchasing parts for fabricating the
loop that Portstevos had posted in the Files Section whereby i would
like to seek members further knowledge on the original Kyle KOLR
Remote-tuned Loop Pre-amp design....

May i enquire is the loop as indicated in Kyle's schematic is
referring to the main loop or the smaller coupling loop? (pls refer
to filename loopdiagram1 for the schematic....)

The pre-amp is placed on the main loop. The main loop (inductor) and
capacitor (here a varactor setup) forms a parallel resonant (tuned)
circuit. In a small loop, the coupling loop is half of a transformer,
converting the low impedance of the main loop (well under 1 ohm) up to
50 ohms, (the standard input for the radio) which achieves maximum
power transfer.

Reason being i would like to try out Kyle's design of using varactor
(tuning) diodes as a tuning capacitor for the main loop...

However, if the loop in the schematic is referring to the main loop,
then i'm a bit confused at which point in the Pre-amp circuit board
do i solder the coupling loop feedline for signal pre-amplification
before going out to the receiver.

No tuning loop is needed with the pre-amp. The output of the
amplifier (the emitter follower) is set for the maximum power
transfer to the receiver.

best regards,

Alan Wong

Hi Dave,

please correct me if i'm wrong as i'm just a beginner in loop antennas....

in summary, if i were to build a remote tuned loop based on Kyle KOLR
design, the tuning & preamp circuit board will be attached to the main
loop while i still need another smaller coupling loop (ie. as what
Portstevos
has illustrated in his phots) as a feedline into my receiver......

if this is so, do i need another preamp to be connected to the coupling
loop?

as alternative, could i just feed into my receiver from the main loop
without
the use of any coupling loop similar to the WL1030 design?....

please forgive if my above queries sounds a bit silly as i'm still
grasping around
on antennas designs....

best regards,

Alan Wong






"dldorrance" <dldorrance@...>
Sent by: loopantennas@...
07/07/2007 03:48 AM
Please respond to loopantennas

To: loopantennas@...
cc:
Subject: [loopantennas] Re: Remote_Tuned_Loop By Portstevos


Hi Alan,

Please see inline responses.

Dave WA6YSO

--- In loopantennas@..., "alamdamai1" <mwwong@...> wrote:

Hi,

I'm currently in the process of purchasing parts for fabricating the
loop that Portstevos had posted in the Files Section whereby i would
like to seek members further knowledge on the original Kyle KOLR
Remote-tuned Loop Pre-amp design....

May i enquire is the loop as indicated in Kyle's schematic is
referring to the main loop or the smaller coupling loop? (pls refer
to filename loopdiagram1 for the schematic....)

The pre-amp is placed on the main loop. The main loop (inductor) and
capacitor (here a varactor setup) forms a parallel resonant (tuned)
circuit. In a small loop, the coupling loop is half of a transformer,
converting the low impedance of the main loop (well under 1 ohm) up to
50 ohms, (the standard input for the radio) which achieves maximum
power transfer.

Reason being i would like to try out Kyle's design of using varactor
(tuning) diodes as a tuning capacitor for the main loop...

However, if the loop in the schematic is referring to the main loop,
then i'm a bit confused at which point in the Pre-amp circuit board
do i solder the coupling loop feedline for signal pre-amplification
before going out to the receiver.

No tuning loop is needed with the pre-amp. The output of the
amplifier (the emitter follower) is set for the maximum power
transfer to the receiver.

best regards,

Alan Wong

At 12:49 pm ((PDT)) Fri Jul 6, 2007, dldorrance wrote:

[snip]
The pre-amp is placed on the main loop.

Across a tuned loop if it is a high-input-impedance pre-amp
(i.e. a JFET-input amplifier); or in series with the loop and
its tuning capacitor (if any) for a very-low-impedance pre-amp;
otherwise use a matching transformation (not necessarily
a wound transformer).

The main loop (inductor) and
capacitor (here a varactor setup) forms a parallel resonant (tuned)
circuit.

So it is very high impedance.

In a small loop,

For an electrically small receiving loop, where the length of the
conductor is typically one-tenth wavelength or less, the loop will
consist of a single turn or a small number of turns, except at VLF.

the coupling loop is half of a transformer,

With the main loop forming the primary having a few turns or
one turn; and the coupling loop forming the secondary with one
turn or one reduced-area turn.

So it is an impedance step-down ratio transformer.

converting the low impedance of the main loop (well under 1 ohm)

No - you have said it is parallel-resonant so it is high impedance.
For a series-resonant loop, the impedance is the radiation
resistance plus the RF resistance of the loop which basically
depends on how much copper you can afford to put into it.

up to

No - it's definitely a step-down transformer.

50 ohms, (the standard input for the radio)

That depends on the radio (my HF-150 has 50 ohm,
600 ohm and high-impedance for a whip) and on the
feeder you use to connect to it - which may be what
is to hand rather than what you would have chosen..

Radio coax is commonly 50 ohms but TV coax is 75 ohms.

Twin feeder is typically 300, 450 or 600-ish ohms.

Basically, if you want the matching to be independent of
frequency and feeder length, you match to the characteristic
impedance of the feeder and, if necessary, match the feeder
to the radio at the other end.


Regards, LenW
--
From Yahoo! Groups Help: ... trim all the irrelevant quoted text
out of your message (as a courtesy to the other members of
the group to make the digest easier to read).

Hi Alan,

Please see inline responses.

Dave WA6YSO

--- In loopantennas@..., "alamdamai1" <mwwong@...> wrote:

Hi,

I'm currently in the process of purchasing parts for fabricating the
loop that Portstevos had posted in the Files Section whereby i would
like to seek members further knowledge on the original Kyle KOLR
Remote-tuned Loop Pre-amp design....

May i enquire is the loop as indicated in Kyle's schematic is
referring to the main loop or the smaller coupling loop? (pls refer
to filename loopdiagram1 for the schematic....)

The pre-amp is placed on the main loop. The main loop (inductor) and
capacitor (here a varactor setup) forms a parallel resonant (tuned)
circuit. In a small loop, the coupling loop is half of a transformer,
converting the low impedance of the main loop (well under 1 ohm) up to
50 ohms, (the standard input for the radio) which achieves maximum
power transfer.

Reason being i would like to try out Kyle's design of using varactor
(tuning) diodes as a tuning capacitor for the main loop...

However, if the loop in the schematic is referring to the main loop,
then i'm a bit confused at which point in the Pre-amp circuit board
do i solder the coupling loop feedline for signal pre-amplification
before going out to the receiver.

No tuning loop is needed with the pre-amp. The output of the
amplifier (the emitter follower) is set for the maximum power
transfer to the receiver.

best regards,

Alan Wong

Howday Mate.....

thanks Michael for sharing with us on what you went through....

well, my MVAM108 has yet to arrive from the States and once i've
assemble the board, will definately post it in this Group on its
outcome....

Alan Wong.




"portstevos" <portstevos@...>
Sent by: loopantennas@...
07/05/2007 06:40 PM
Please respond to loopantennas

To: loopantennas@...
cc:
Subject: [loopantennas] Re: Remote_Tuned_Loop By Portstevos


--- In loopantennas@..., "alamdamai1" <mwwong@...> wrote:

Hi,

I'm currently in the process of purchasing parts for fabricating the
loop that Portstevos had posted in the Files Section whereby i would
like to seek members further knowledge on the original Kyle KOLR
Remote-tuned Loop Pre-amp design....

May i enquire is the loop as indicated in Kyle's schematic is
referring to the main loop or the smaller coupling loop? (pls refer
to filename loopdiagram1 for the schematic....)

Reason being i would like to try out Kyle's design of using varactor
(tuning) diodes as a tuning capacitor for the main loop...

However, if the loop in the schematic is referring to the main loop,
then i'm a bit confused at which point in the Pre-amp circuit board
do i solder the coupling loop feedline for signal pre-amplification
before going out to the receiver?

best regards,

Alan Wong

Hello, The Kyle schematic is for the main loop because when using
varicaps with Kyle's design then there is no coupling loop. I have
tried various experiments and variations of design such as varicaps
onto the main loop with and without the pre-amp, I also tried using
the varicaps to tune the main loop while using a coupling loop with
and without the pre-amp and I have tried varicaps and pre-amp coming
from the coupling loop.

I don't know if I used the incorrect type of varicaps or if there are
any better types available but I could not get anywhere near the same
sensitivity and signal to noise ratio, peaking, bandwidth or 'Q' from
any of the designs using varicaps in comparison to an old fashioned
tuning gang on the main loop and the pre-amp on the coupling loop, it
just seem's to be a magic combination for me and has proved to be
reliable with excellant sensitivity and signal to noise ratio right
across the frequencies it tunes which is from 2.3 up to 18 MHz (tuning
to the lower frequencies below 4.7 MHz with the help of a remote
switching relay to pull in extra capacitance across the main tuning gang!)

I have also tried an old fashioned tuning gang on the main loop
without a coupling loop with and without a pre-amp but the best
performance still comes down to the design that has been posted.

Best wishes from down under where it is freezing tonight!

Michael S

--- In loopantennas@..., "alamdamai1" <mwwong@...> wrote:

Hi,

I'm currently in the process of purchasing parts for fabricating the
loop that Portstevos had posted in the Files Section whereby i would
like to seek members further knowledge on the original Kyle KOLR
Remote-tuned Loop Pre-amp design....

May i enquire is the loop as indicated in Kyle's schematic is
referring to the main loop or the smaller coupling loop? (pls refer
to filename loopdiagram1 for the schematic....)

Reason being i would like to try out Kyle's design of using varactor
(tuning) diodes as a tuning capacitor for the main loop...

However, if the loop in the schematic is referring to the main loop,
then i'm a bit confused at which point in the Pre-amp circuit board
do i solder the coupling loop feedline for signal pre-amplification
before going out to the receiver?

best regards,

Alan Wong

Hello, The Kyle schematic is for the main loop because when using
varicaps with Kyle's design then there is no coupling loop. I have
tried various experiments and variations of design such as varicaps
onto the main loop with and without the pre-amp, I also tried using
the varicaps to tune the main loop while using a coupling loop with
and without the pre-amp and I have tried varicaps and pre-amp coming
from the coupling loop.

I don't know if I used the incorrect type of varicaps or if there are
any better types available but I could not get anywhere near the same
sensitivity and signal to noise ratio, peaking, bandwidth or 'Q' from
any of the designs using varicaps in comparison to an old fashioned
tuning gang on the main loop and the pre-amp on the coupling loop, it
just seem's to be a magic combination for me and has proved to be
reliable with excellant sensitivity and signal to noise ratio right
across the frequencies it tunes which is from 2.3 up to 18 MHz (tuning
to the lower frequencies below 4.7 MHz with the help of a remote
switching relay to pull in extra capacitance across the main tuning gang!)

I have also tried an old fashioned tuning gang on the main loop
without a coupling loop with and without a pre-amp but the best
performance still comes down to the design that has been posted.

Best wishes from down under where it is freezing tonight!

Michael S

Hi,

I'm currently in the process of purchasing parts for fabricating the
loop that Portstevos had posted in the Files Section whereby i would
like to seek members further knowledge on the original Kyle KOLR
Remote-tuned Loop Pre-amp design....

May i enquire is the loop as indicated in Kyle's schematic is
referring to the main loop or the smaller coupling loop? (pls refer
to filename loopdiagram1 for the schematic....)

Reason being i would like to try out Kyle's design of using varactor
(tuning) diodes as a tuning capacitor for the main loop...

However, if the loop in the schematic is referring to the main loop,
then i'm a bit confused at which point in the Pre-amp circuit board
do i solder the coupling loop feedline for signal pre-amplification
before going out to the receiver?

best regards,

Alan Wong

Hi Scott,

About a year ago I put up a 204ft G5RV from the roof of my rancher
to 2 trees in a vee 102ft long about 65ft apart. The heighth is about
20feet. This worked pretty well on most bands. About four months back
I added copper wire across the ends by the trees and another about
twenty feet from the house, making it a closed loop. This made a big
difference in the quieting down of noise and in return signals were
clearer. Even though this is in not a rectangle it is a closed loop
proving to me they are quieter.
Ed Dawson

Antena Software.

I have made a list (6 months old ;-) that collects all software that works for linux. Once you've setup a linux box with debian/ ubuntu, installing is a matter of clicking. (installing linux too ;-)


Of course, the antenna software isn't that simple ... sometimes it runs in shell, (DOS like)... sometimes you need to give a lot of variables ...
I would like somebody that explains all this stuff to me. Location (near the brewery ;-)

Marc

other pages:
loop calculator in CM (meters)


pictures of loops:


--
--
Shortwave transmissions in English, Francais, Nederlands, Deutsch, Suid-Afrikaans, Chinese, Dansk, Urdu, Cantonese, Greek, Spanish, Portuguese, ...
Updated every month or so ...

Hi, Scott

While I am not an expert on horizontally-oriented loops (or any
loops, for that matter - hi), I have also been researching them and
have found a few web sites that have good designs. I guess I should
disclaim any connection with these websites and any responsibility
for the material they present. Having gotten that out of the way,
here are the websites that might be useful and I am sure there are
more (ARRL and W4RNL for example):

Great site - an antenna master

Good details







I hope this helps.

Happy Independence Day and 73,
Jim K9RII




--- In loopantennas@..., "ka7nwq" <ka7nwq@...> wrote:

--- In loopantennas@..., "peterzel" <wa4fki@> wrote:

--- In loopantennas@..., "ka7nwq" <ka7nwq@> wrote:

Hey all. I had a few questions that I hope that some of you

may

be

able to answer. I am itching to put up a loop, mainly for the

low

noise feature that the loop has. I at minimum have 45 feet

across by

maybe 150 or so long to hang this thing. Further, height,

trees,

towers and blackberry vines are an issue. Anyone have

experience with

low hanging loops? Any information would be greatly

appreciated.

73's and dx

scott
KA7NWQ

HELLO Scott, interesting about your antenna, what band do you

plan

on

using it on? I am experimenting with LOOP antennas for 160

meters,

do

the design on an antenna program on the computer...

73's
Bill
WA4FKI

thanks for the reply. I would love to cut it for 80 meters,
however, probably going to have to stick with 40 on up. I
understand about the cloudwarmer effect and the higher the better,
so I guess we will just have to play with it a bit. Are you aware
of any dummy proof ant programs on the internet that would help?

I

have played with the EZNEC demo program and I am not familar

enough

with that one to make it work. thanks again

HI, if you have the demo EZNEX program (free to use) I will send you a EZNEC fille you can put into your program and it will display some of the loop antennas in question....

I suggest you try a K9AY antenna, it is not a loop but a triangle, I used for a receiving (cannot transmit on it) for several years, it is very good, when I first connected to my receiver (Drake R4B) thought something in the receiver was not working, there was hardly any noise... Check the Internet for construction.

Bill
WA4FKI

--- In loopantennas@..., Jim Dunstan <jdunstan@...>
wrote:

At 01:15 PM 7/4/2007 +0000, you wrote:

Hey all. I had a few questions that I hope that some of you may be
able to answer. I am itching to put up a loop, mainly for the low
noise feature that the loop has. I at minimum have 45 feet across

by

maybe 150 or so long to hang this thing. Further, height, trees,
towers and blackberry vines are an issue. Anyone have experience

with

low hanging loops? Any information would be greatly appreciated.

73's and dx

scott
KA7NWQ

Hi Scott,

Generally speaking low horizontally polarized antennas ... loops

or dipoles

are cloud burners .... That doesn't mean you won't hear some

distant

stations when conditions are really good ... and even work a

few ... but

the bulk of the power radiated and signals received will be at a

high

angle. However, such low strung antennas are the antenna of

choice for

close HF communications. For example HF communications for

trappers and

hunters in the north (frequencies in the 5Mhz range) work very

well out to

about 100 miles (30-50mi are the norm) with SSB transceivers

running 2 to 5

watts using dipoles up as little as 10-20 ft.

If you want to work out further on a consistent basis with a

horizontally

oriented antenna there really is no substitute for height. For a

dipole

the ideal is 1 wavelength in height while a loop will do as well

at a

slightly lower height .... especially if you make the loop 2

wavelengths in

circumference. Cebik has some really good articles on loop

performance on

the internet.

Jim, VE3CI

thanks for your reply. I would love an 80 meter, however, will
probably have to go with a 40 meter loop. I cant decide wether or
not to go horizontal plane or vertical. I would really like to hear
better than I am right now. Cloudwarmer for sure, especially at the
low height......thanks again

--- In loopantennas@..., "peterzel" <wa4fki@...> wrote:

--- In loopantennas@..., "ka7nwq" <ka7nwq@> wrote:

Hey all. I had a few questions that I hope that some of you may

be

able to answer. I am itching to put up a loop, mainly for the

low

noise feature that the loop has. I at minimum have 45 feet

across by

maybe 150 or so long to hang this thing. Further, height,

trees,

towers and blackberry vines are an issue. Anyone have

experience with

low hanging loops? Any information would be greatly appreciated.

73's and dx

scott
KA7NWQ

HELLO Scott, interesting about your antenna, what band do you plan

on

using it on? I am experimenting with LOOP antennas for 160 meters,

do

the design on an antenna program on the computer...

73's
Bill
WA4FKI

thanks for the reply. I would love to cut it for 80 meters,
however, probably going to have to stick with 40 on up. I
understand about the cloudwarmer effect and the higher the better,
so I guess we will just have to play with it a bit. Are you aware
of any dummy proof ant programs on the internet that would help? I
have played with the EZNEC demo program and I am not familar enough
with that one to make it work. thanks again

Jim, thanks for the feedback but I differ with your comments, first EZNEC antenna modeling program precicts a take off angle between 18 and 26 degrees. This loop or loops will only be used for receiving.. While the conventional thinking is the higher the better look at the Half Square antenna, low angle of radiation in the 22 degree area, it thrives on low to the ground elements. My 40 meter and 20 meter Half Square antenna is only 10 feet off the ground, with QRP I have worked WAC in a short time... Great antenas....

Back to the loops, two small loops in phase provide about -35 db gain has a fine front to back ratio and hear very well. As an example, this station in Florida can now hear stations that others who have long Beverage antennas..

Thanks...

73's
Bill
WA4FKI

At 01:15 PM 7/4/2007 +0000, you wrote:

Hey all. I had a few questions that I hope that some of you may be
able to answer. I am itching to put up a loop, mainly for the low
noise feature that the loop has. I at minimum have 45 feet across by
maybe 150 or so long to hang this thing. Further, height, trees,
towers and blackberry vines are an issue. Anyone have experience with
low hanging loops? Any information would be greatly appreciated.

73's and dx

scott
KA7NWQ

Hi Scott,

Generally speaking low horizontally polarized antennas ... loops or dipoles are cloud burners .... That doesn't mean you won't hear some distant stations when conditions are really good ... and even work a few ... but the bulk of the power radiated and signals received will be at a high angle. However, such low strung antennas are the antenna of choice for close HF communications. For example HF communications for trappers and hunters in the north (frequencies in the 5Mhz range) work very well out to about 100 miles (30-50mi are the norm) with SSB transceivers running 2 to 5 watts using dipoles up as little as 10-20 ft.

If you want to work out further on a consistent basis with a horizontally oriented antenna there really is no substitute for height. For a dipole the ideal is 1 wavelength in height while a loop will do as well at a slightly lower height .... especially if you make the loop 2 wavelengths in circumference. Cebik has some really good articles on loop performance on the internet.

Jim, VE3CI

--- In loopantennas@..., "ka7nwq" <ka7nwq@...> wrote:

Hey all. I had a few questions that I hope that some of you may be
able to answer. I am itching to put up a loop, mainly for the low
noise feature that the loop has. I at minimum have 45 feet across by
maybe 150 or so long to hang this thing. Further, height, trees,
towers and blackberry vines are an issue. Anyone have experience with
low hanging loops? Any information would be greatly appreciated.

73's and dx

scott
KA7NWQ

HELLO Scott, interesting about your antenna, what band do you plan on
using it on? I am experimenting with LOOP antennas for 160 meters, do
the design on an antenna program on the computer...

73's
Bill
WA4FKI