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Re: WELLBROOK DIY

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  • iv3zbl
    ... Try Google wl1030 and let us know how your project goes on. 73 Andy IV3ZBL
    Message 1 of 20 , Jan 18, 2011
      >
      > Also a schematic for an amp to match that performance quality, or a
      > commercially available one ?
      >

      Try Google "wl1030" and let us know how your project goes on.

      73 Andy IV3ZBL
    • dx11
      See also: Wideband Loop Antenna Amplifier RevA.pdf in the files section of this group. Regards, Cor Beijersbergen
      Message 2 of 20 , Jan 18, 2011
        See also: "Wideband Loop Antenna Amplifier RevA.pdf " in the files
        section of this group.

        Regards,

        Cor Beijersbergen
      • dx11
        And: http://www.lz1aq.signacor.com/docs/wsml/wideband-active-sm-loop-antenna.htm Regards, Cor Beijersbergen
        Message 3 of 20 , Jan 18, 2011
        • dx11
          And another one: http://www.pm.keirle.com/3_radio/hf_loop_ant/hf_loop_ant.htm Cor Beijersbergen
          Message 4 of 20 , Jan 18, 2011
          • skyspeed77
            ... Thank you Andy and the others who responded to my request regarding the Wellbrook Loop. I ve learned some key elements from those links. Truthfully I m
            Message 5 of 20 , Jan 19, 2011
              --- In loopantennas@yahoogroups.com, "iv3zbl" <iv3zbl@...> wrote:
              >
              > >
              > > Also a schematic for an amp to match that performance quality, or a
              > > commercially available one ?
              > >
              >
              > Try Google "wl1030" and let us know how your project goes on.
              >
              > 73 Andy IV3ZBL
              >

              Thank you Andy and the others who responded to my request regarding the
              Wellbrook Loop. I've learned some key elements from those links.

              Truthfully I'm good with mechanics, BUT my confidence to scratch build
              an antenna amp is missing.
              Are their any amps available for purchase to match the performance of
              the
              Wellbrook one, from MFJ or another company ?
              In kit form would work.

              Changing the subject a bit, I have a 23-inch embroidery hoop to build a
              wire loop with. Is Litz wire the best to use for this or will stranded
              or solid work almost as well ?
              I bought a 381-pf variable cap; will that cover the whole 520-1700 khz
              range,
              or do I need to have an added switched-in additional fixed or variable
              cap ?

              Is it OK to use a soft copper 1/2" pipe for the coupling coil of a
              multi-turn wire
              loop ?

              Corky
            • Schick, David
              The key performance parameter of all of these wideband loops, in my opinion, is the nonlinearity performance. Does anyone have a simple way to test the
              Message 6 of 20 , Jan 19, 2011
                The key performance parameter of all of these wideband loops, in my opinion,
                is the nonlinearity performance.

                Does anyone have a simple way to test the nonlinearity performance of a
                wideband receiving loop? The challenge arises from the fact that the
                antenna really must be in the circuit in order to match the amplifier's
                input impedance across many frequencies.

                One thing that occurs to me is to have a measuring receiver and antenna
                which would dynamically measure the field strength of shortwave AM carriers
                and then use that information to measure the second and third order
                intermodulation products on the test device?

                Dave

                On Wed, Jan 19, 2011 at 15:16, skyspeed77 <skyspeed77@...> wrote:

                >
                > --- In loopantennas@yahoogroups.com, "iv3zbl" <iv3zbl@...> wrote:
                > >
                > > >
                > > > Also a schematic for an amp to match that performance quality, or a
                > > > commercially available one ?
                > > >
                > >
                > > Try Google "wl1030" and let us know how your project goes on.
                > >
                > > 73 Andy IV3ZBL
                > >
                >
                > Thank you Andy and the others who responded to my request regarding the
                > Wellbrook Loop. I've learned some key elements from those links.
                >
                > Truthfully I'm good with mechanics, BUT my confidence to scratch build
                > an antenna amp is missing.
                > Are their any amps available for purchase to match the performance of
                > the
                > Wellbrook one, from MFJ or another company ?
                > In kit form would work.
                >
                > Changing the subject a bit, I have a 23-inch embroidery hoop to build a
                > wire loop with. Is Litz wire the best to use for this or will stranded
                > or solid work almost as well ?
                > I bought a 381-pf variable cap; will that cover the whole 520-1700 khz
                > range,
                > or do I need to have an added switched-in additional fixed or variable
                > cap ?
                >
                > Is it OK to use a soft copper 1/2" pipe for the coupling coil of a
                > multi-turn wire
                > loop ?
                >
                > Corky
                >
                >
                >
                >
                > ------------------------------------
                >
                > If you've got links, post them in the Links section!
                > http://groups.yahoo.com/group/loopantennas/links
                >
                > Post files here. If the file comes from a website, please put it in the
                > Links rather than uploading the file.
                > http://groups.yahoo.com/group/loopantennas/files
                >
                > You can now view images at higher resolution in Photos. Upload JPG and GIF
                > into Photos. Please convert BMP or TIF to JPG or GIF before uploading.
                > http://ph.groups.yahoo.com/group/loopantennas/photos
                >
                > And please trim all this when replying!Yahoo! Groups Links
                >
                >
                >
                >


                [Non-text portions of this message have been removed]
              • Ray Phillips
                Corky, To tune across the whole extended AM band you need a tuning capacitor with a minimum to maximum ratio of nearly 1:11. This means that your 381pF
                Message 7 of 20 , Jan 19, 2011
                  Corky,

                  To tune across the whole extended AM band you need a tuning capacitor with a minimum to maximum ratio of nearly 1:11.
                  This means that your 381pF capacitor needs to have a minimum of 34pF or less. This presumes that your loop has the perfect inductance of 246uH.
                  As your loop will be wound in complete turns, a perfect inductance is unlikely and so you would need a lower minimum capacitor value so you have a bit of leeway, if you want a single capacitor.

                  Experiment with the number of turns until the loop tunes OK at the 1700kHz end of the band with the capacitor completely open (plates unmeshed). Use complete turns for coarse adjustment and then manipulate the turn spacing for the fine adjustment. Moving turns apart will raise the frequency and vice-versa. When the upper end is lined up, close the capacitor and check the frequency. If it is not 520kHZ or less, you will need to switch in an additional capacitor when tuning the low end of the band. Bear in mind that any conductor in the near field of the loop will affect its frequency and so you need to have your pick up winding(s) in place before winding on the tuning loop itself and that any capacitor switching arrangement will introduce stray capacitance and stray inductance that will also affect loop tuning.

                  If I was building it, I wouldn't try to make a perfect loop. I would build one loop that catches one end of the band to at least the middle of the band and a second loop that catches the other end to the middle. So there's a bit of unwanted tuning range - not the end of the world. Use a changeover switch or banana plugs to connect them.

                  In a small, multi-turn loop, the "Q" or efficiency (for want of a better term) is not at the pinnacle of loop Q's. This means that you don't have to be too fussy about the pick up loop. The half inch copper pipe should work fine but is overkill and is a pain to bend to shape. Just use the same wire as the loop. Make the length of the pickup loop about one tenth to one fifth of the tuning loop length. If you have to wind more than one turn then so be it.

                  I once made an AM loop that was more art than technology. Stood about three feet high. The loop was shaped like the sails of a polynesian boat with the base shaped like a stylised polynesian multi-hull proa (I said it was art). It had 11 turns for the tuning loop and one for the pickup loop. I started out with a guess of 13 turns and removed them one at a time until I was happy with the inductance. None of this copper wire business either; I used fine galvanised iron wire. In the middle of the day it would take an unreadable 2KW station 150 miles away and tune so that the station audio was nearly perfect and almost completely noise free - quite acceptable listening quality. Of course its performance could have been improved but it did its job well enough and was arty-farty enough to not incur the wrath of "her indoors".

                  Nicely working small loops are easy-peasy - it's perfecting them that makes things hard. Make your first loop with confidence but with the knowledge that it may not be exactly what you want and that you will learn a lot that will enable you to build a better loop next time. But, be warned, trying to improve your loop can become addictive.


                  All the best,
                  Ray vk5ugs


                  To: loopantennas@yahoogroups.com
                  From: skyspeed77@...
                  Date: Wed, 19 Jan 2011 20:16:02 +0000
                  Subject: [loopantennas] Re: WELLBROOK DIY






























                  --- In loopantennas@yahoogroups.com, "iv3zbl" <iv3zbl@...> wrote:

                  >

                  > >

                  > > Also a schematic for an amp to match that performance quality, or a

                  > > commercially available one ?

                  > >

                  >

                  > Try Google "wl1030" and let us know how your project goes on.

                  >

                  > 73 Andy IV3ZBL

                  >



                  Thank you Andy and the others who responded to my request regarding the

                  Wellbrook Loop. I've learned some key elements from those links.



                  Truthfully I'm good with mechanics, BUT my confidence to scratch build

                  an antenna amp is missing.

                  Are their any amps available for purchase to match the performance of

                  the

                  Wellbrook one, from MFJ or another company ?

                  In kit form would work.



                  Changing the subject a bit, I have a 23-inch embroidery hoop to build a

                  wire loop with. Is Litz wire the best to use for this or will stranded

                  or solid work almost as well ?

                  I bought a 381-pf variable cap; will that cover the whole 520-1700 khz

                  range,

                  or do I need to have an added switched-in additional fixed or variable

                  cap ?



                  Is it OK to use a soft copper 1/2" pipe for the coupling coil of a

                  multi-turn wire

                  loop ?



                  Corky


















                  [Non-text portions of this message have been removed]
                • Steve Ellington
                  Ray: Your use of the idiom arty-farty drove me to Google. Now that I know the meaning, I m am seriously considering some form of ornamental loop for the front
                  Message 8 of 20 , Jan 19, 2011
                    Ray:
                    Your use of the idiom arty-farty drove me to Google. Now that I know the
                    meaning, I'm am seriously considering some form of ornamental loop for the
                    front yard.
                    This photo of some loops in Raleigh, NC. make me feel secure about this form
                    of "art" on my property.
                    http://www.flickr.com/photos/bernard-pics/4732970897/


                    Steve
                    N4LQ
                    ----- Original Message -----
                    From: "Ray Phillips" <uggliozzi@...>
                    To: <loopantennas@yahoogroups.com>
                    Sent: Wednesday, January 19, 2011 7:50 PM
                    Subject: RE: [loopantennas] Re: WELLBROOK DIY


                    >
                    > Corky,
                    >
                    > To tune across the whole extended AM band you need a tuning capacitor with
                    > a minimum to maximum ratio of nearly 1:11.
                    > This means that your 381pF capacitor needs to have a minimum of 34pF or
                    > less. This presumes that your loop has the perfect inductance of 246uH.
                    > As your loop will be wound in complete turns, a perfect inductance is
                    > unlikely and so you would need a lower minimum capacitor value so you have
                    > a bit of leeway, if you want a single capacitor.
                    >
                    > Experiment with the number of turns until the loop tunes OK at the 1700kHz
                    > end of the band with the capacitor completely open (plates unmeshed). Use
                    > complete turns for coarse adjustment and then manipulate the turn spacing
                    > for the fine adjustment. Moving turns apart will raise the frequency and
                    > vice-versa. When the upper end is lined up, close the capacitor and check
                    > the frequency. If it is not 520kHZ or less, you will need to switch in an
                    > additional capacitor when tuning the low end of the band. Bear in mind
                    > that any conductor in the near field of the loop will affect its frequency
                    > and so you need to have your pick up winding(s) in place before winding on
                    > the tuning loop itself and that any capacitor switching arrangement will
                    > introduce stray capacitance and stray inductance that will also affect
                    > loop tuning.
                    >
                    > If I was building it, I wouldn't try to make a perfect loop. I would
                    > build one loop that catches one end of the band to at least the middle of
                    > the band and a second loop that catches the other end to the middle. So
                    > there's a bit of unwanted tuning range - not the end of the world. Use a
                    > changeover switch or banana plugs to connect them.
                    >
                    > In a small, multi-turn loop, the "Q" or efficiency (for want of a better
                    > term) is not at the pinnacle of loop Q's. This means that you don't have
                    > to be too fussy about the pick up loop. The half inch copper pipe should
                    > work fine but is overkill and is a pain to bend to shape. Just use the
                    > same wire as the loop. Make the length of the pickup loop about one tenth
                    > to one fifth of the tuning loop length. If you have to wind more than one
                    > turn then so be it.
                    >
                    > I once made an AM loop that was more art than technology. Stood about
                    > three feet high. The loop was shaped like the sails of a polynesian boat
                    > with the base shaped like a stylised polynesian multi-hull proa (I said it
                    > was art). It had 11 turns for the tuning loop and one for the pickup
                    > loop. I started out with a guess of 13 turns and removed them one at a
                    > time until I was happy with the inductance. None of this copper wire
                    > business either; I used fine galvanised iron wire. In the middle of the
                    > day it would take an unreadable 2KW station 150 miles away and tune so
                    > that the station audio was nearly perfect and almost completely noise
                    > free - quite acceptable listening quality. Of course its performance
                    > could have been improved but it did its job well enough and was arty-farty
                    > enough to not incur the wrath of "her indoors".
                    >
                    > Nicely working small loops are easy-peasy - it's perfecting them that
                    > makes things hard. Make your first loop with confidence but with the
                    > knowledge that it may not be exactly what you want and that you will learn
                    > a lot that will enable you to build a better loop next time. But, be
                    > warned, trying to improve your loop can become addictive.
                    >
                    >
                    > All the best,
                    > Ray vk5ugs
                    >
                    >
                    > To: loopantennas@yahoogroups.com
                    > From: skyspeed77@...
                    > Date: Wed, 19 Jan 2011 20:16:02 +0000
                    > Subject: [loopantennas] Re: WELLBROOK DIY
                    >
                    >
                    >
                    >
                    >
                    >
                    >
                    >
                    >
                    >
                    >
                    >
                    >
                    >
                    >
                    >
                    >
                    >
                    >
                    >
                    >
                    >
                    >
                    >
                    >
                    >
                    >
                    >
                    >
                    >
                    > --- In loopantennas@yahoogroups.com, "iv3zbl" <iv3zbl@...> wrote:
                    >
                    >>
                    >
                    >> >
                    >
                    >> > Also a schematic for an amp to match that performance quality, or a
                    >
                    >> > commercially available one ?
                    >
                    >> >
                    >
                    >>
                    >
                    >> Try Google "wl1030" and let us know how your project goes on.
                    >
                    >>
                    >
                    >> 73 Andy IV3ZBL
                    >
                    >>
                    >
                    >
                    >
                    > Thank you Andy and the others who responded to my request regarding the
                    >
                    > Wellbrook Loop. I've learned some key elements from those links.
                    >
                    >
                    >
                    > Truthfully I'm good with mechanics, BUT my confidence to scratch build
                    >
                    > an antenna amp is missing.
                    >
                    > Are their any amps available for purchase to match the performance of
                    >
                    > the
                    >
                    > Wellbrook one, from MFJ or another company ?
                    >
                    > In kit form would work.
                    >
                    >
                    >
                    > Changing the subject a bit, I have a 23-inch embroidery hoop to build a
                    >
                    > wire loop with. Is Litz wire the best to use for this or will stranded
                    >
                    > or solid work almost as well ?
                    >
                    > I bought a 381-pf variable cap; will that cover the whole 520-1700 khz
                    >
                    > range,
                    >
                    > or do I need to have an added switched-in additional fixed or variable
                    >
                    > cap ?
                    >
                    >
                    >
                    > Is it OK to use a soft copper 1/2" pipe for the coupling coil of a
                    >
                    > multi-turn wire
                    >
                    > loop ?
                    >
                    >
                    >
                    > Corky
                    >
                    >
                    >
                    >
                    >
                    >
                    >
                    >
                    >
                    >
                    >
                    >
                    >
                    >
                    >
                    >
                    >
                    >
                    > [Non-text portions of this message have been removed]
                    >
                    >
                    >
                    > ------------------------------------
                    >
                    > If you've got links, post them in the Links section!
                    > http://groups.yahoo.com/group/loopantennas/links
                    >
                    > Post files here. If the file comes from a website, please put it in the
                    > Links rather than uploading the file.
                    > http://groups.yahoo.com/group/loopantennas/files
                    >
                    > You can now view images at higher resolution in Photos. Upload JPG and GIF
                    > into Photos. Please convert BMP or TIF to JPG or GIF before uploading.
                    > http://ph.groups.yahoo.com/group/loopantennas/photos
                    >
                    > And please trim all this when replying!Yahoo! Groups Links
                    >
                    >
                    >
                  • longjohn119
                    Chris Trask has a couple of tuned and untuned loop designs. Don t discount the active short verticals either, unless you have a specific noise source you need
                    Message 9 of 20 , Jan 19, 2011
                      Chris Trask has a couple of tuned and untuned loop designs. Don't discount the active short verticals either, unless you have a specific noise source you need to null they are just as quiet as an active loop if you get them out in the open.

                      http://home.earthlink.net/~christrask/

                      Down at the bottom of the page but don't overlook the other stuff he has there, especially his work on augmented amps and mixers, and the stuff on transistor evaluations.

                      JR

                      --- In loopantennas@yahoogroups.com, "skyspeed77" <skyspeed77@...> wrote:
                      >
                      > Has anyone reverse engineered the Wellbrook Loop and setup a similar
                      > DIY formula for building your own, perhaps of copper tubing ?
                      >
                      > Also a schematic for an amp to match that performance quality, or a
                      > commercially available one ?
                      >
                      > Later I have some questions about wire loops with variable caps, which I've been studying seriously and gathering components.
                      >
                      > I'm an SWL with a current interest in the AM band, but will likely go back to shortwave soon.
                      > My listening location is poor but I haver access to a second story roof. Poor means a building twice the height to the West and main street with lots of visable transformers on the power poles, first floor location, about 100 feet back from the power poles. I'm in L.A.
                      > and also have some interest in DXing the Tropic Bands.
                      >
                    • longjohn119
                      Chris has a newer design too he posted in the file section of the Group that looks promising but I haven t tried it myself yet (Waiting until I need other
                      Message 10 of 20 , Jan 19, 2011
                        Chris has a newer design too he posted in the file section of the Group that looks promising but I haven't tried it myself yet (Waiting until I need other parts to justify ordering the MPS6521 transistors) He uses his patented (literally) augmentation technique on the 4 main transistors.

                        http://groups.yahoo.com/group/loopantennas/files/

                        Last file in the list

                        JR

                        --- In loopantennas@yahoogroups.com, "longjohn119" <some_oil_with_your_teaparty@...> wrote:
                        >
                        > Chris Trask has a couple of tuned and untuned loop designs. Don't discount the active short verticals either, unless you have a specific noise source you need to null they are just as quiet as an active loop if you get them out in the open.
                        >
                        > http://home.earthlink.net/~christrask/
                        >
                        > Down at the bottom of the page but don't overlook the other stuff he has there, especially his work on augmented amps and mixers, and the stuff on transistor evaluations.
                        >
                        > JR
                        >
                        > --- In loopantennas@yahoogroups.com, "skyspeed77" <skyspeed77@> wrote:
                        > >
                        > > Has anyone reverse engineered the Wellbrook Loop and setup a similar
                        > > DIY formula for building your own, perhaps of copper tubing ?
                        > >
                        > > Also a schematic for an amp to match that performance quality, or a
                        > > commercially available one ?
                        > >
                        > > Later I have some questions about wire loops with variable caps, which I've been studying seriously and gathering components.
                        > >
                        > > I'm an SWL with a current interest in the AM band, but will likely go back to shortwave soon.
                        > > My listening location is poor but I haver access to a second story roof. Poor means a building twice the height to the West and main street with lots of visable transformers on the power poles, first floor location, about 100 feet back from the power poles. I'm in L.A.
                        > > and also have some interest in DXing the Tropic Bands.
                        > >
                        >
                      • longjohn119
                        I had problems with stability with that design but I was driving it with a 3/4 OD copper loop. Op Amps simply don t work very well with ultra low impedance
                        Message 11 of 20 , Jan 19, 2011
                          I had problems with stability with that design but I was driving it with a 3/4" OD copper loop. Op Amps simply don't work very well with ultra low impedance input. It may be OK with the recommended wire but I wanted a larger capture area and (slightly) lower noise of the large diameter element.

                          A couple of tweaks though and it's a killer dual amplifier on my IQ Pro VFO to get the level up to drive a pair of +7 DBM's. Very linear and stable in that application since the input source impedance is a much more reasonable 50 ohms rather than just a couple

                          JR

                          --- In loopantennas@yahoogroups.com, "iv3zbl" <iv3zbl@...> wrote:
                          >
                          > >
                          > > Also a schematic for an amp to match that performance quality, or a
                          > > commercially available one ?
                          > >
                          >
                          > Try Google "wl1030" and let us know how your project goes on.
                          >
                          > 73 Andy IV3ZBL
                          >
                        • Notareal Too
                          Hi ! One simple(and cheap) pre-amp is here: http://www.kitsandparts.com/rfamp1.1.php BR ... [Non-text portions of this message have been removed]
                          Message 12 of 20 , Jan 20, 2011
                            Hi !
                            One simple(and cheap) pre-amp is here:

                            http://www.kitsandparts.com/rfamp1.1.php

                            BR


                            > To: loopantennas@yahoogroups.com
                            > From: skyspeed77@...
                            > Date: Wed, 19 Jan 2011 20:16:02 +0000
                            > Subject: [loopantennas] Re: WELLBROOK DIY
                            >
                            >
                            > --- In loopantennas@yahoogroups.com, "iv3zbl" <iv3zbl@...> wrote:
                            > >
                            > > >
                            > > > Also a schematic for an amp to match that performance quality, or a
                            > > > commercially available one ?
                            > > >
                            > >
                            > > Try Google "wl1030" and let us know how your project goes on.
                            > >
                            > > 73 Andy IV3ZBL
                            > >
                            >
                            > Thank you Andy and the others who responded to my request regarding the
                            > Wellbrook Loop. I've learned some key elements from those links.
                            >
                            > Truthfully I'm good with mechanics, BUT my confidence to scratch build
                            > an antenna amp is missing.
                            > Are their any amps available for purchase to match the performance of
                            > the
                            > Wellbrook one, from MFJ or another company ?
                            > In kit form would work.
                            >
                            > Changing the subject a bit, I have a 23-inch embroidery hoop to build a
                            > wire loop with. Is Litz wire the best to use for this or will stranded
                            > or solid work almost as well ?
                            > I bought a 381-pf variable cap; will that cover the whole 520-1700 khz
                            > range,
                            > or do I need to have an added switched-in additional fixed or variable
                            > cap ?
                            >
                            > Is it OK to use a soft copper 1/2" pipe for the coupling coil of a
                            > multi-turn wire
                            > loop ?
                            >
                            > Corky
                            >
                            >
                            >
                            >
                            > ------------------------------------
                            >
                            > If you've got links, post them in the Links section!
                            > http://groups.yahoo.com/group/loopantennas/links
                            >
                            > Post files here. If the file comes from a website, please put it in the Links rather than uploading the file.
                            > http://groups.yahoo.com/group/loopantennas/files
                            >
                            > You can now view images at higher resolution in Photos. Upload JPG and GIF into Photos. Please convert BMP or TIF to JPG or GIF before uploading.
                            > http://ph.groups.yahoo.com/group/loopantennas/photos
                            >
                            > And please trim all this when replying!Yahoo! Groups Links
                            >
                            >
                            >


                            [Non-text portions of this message have been removed]
                          • skyspeed77
                            I saw that onem and did order the kit for it. Thanks. Corky
                            Message 13 of 20 , Jan 24, 2011
                              I saw that onem and did order the kit for it. Thanks.
                              Corky

                              --- In loopantennas@yahoogroups.com, Notareal Too <not_a_real@...> wrote:
                              >
                              >
                              > Hi !
                              > One simple(and cheap) pre-amp is here:
                              >
                              > http://www.kitsandparts.com/rfamp1.1.php
                              >
                              > BR
                              >
                              >
                              > > To: loopantennas@yahoogroups.com
                              > > From: skyspeed77@...
                              > > Date: Wed, 19 Jan 2011 20:16:02 +0000
                              > > Subject: [loopantennas] Re: WELLBROOK DIY
                              > >
                              > >
                              > > --- In loopantennas@yahoogroups.com, "iv3zbl" <iv3zbl@> wrote:
                              > > >
                              > > > >
                              > > > > Also a schematic for an amp to match that performance quality, or a
                              > > > > commercially available one ?
                              > > > >
                              > > >
                              > > > Try Google "wl1030" and let us know how your project goes on.
                              > > >
                              > > > 73 Andy IV3ZBL
                              > > >
                              > >
                              > > Thank you Andy and the others who responded to my request regarding the
                              > > Wellbrook Loop. I've learned some key elements from those links.
                              > >
                              > > Truthfully I'm good with mechanics, BUT my confidence to scratch build
                              > > an antenna amp is missing.
                              > > Are their any amps available for purchase to match the performance of
                              > > the
                              > > Wellbrook one, from MFJ or another company ?
                              > > In kit form would work.
                              > >
                              > > Changing the subject a bit, I have a 23-inch embroidery hoop to build a
                              > > wire loop with. Is Litz wire the best to use for this or will stranded
                              > > or solid work almost as well ?
                              > > I bought a 381-pf variable cap; will that cover the whole 520-1700 khz
                              > > range,
                              > > or do I need to have an added switched-in additional fixed or variable
                              > > cap ?
                              > >
                              > > Is it OK to use a soft copper 1/2" pipe for the coupling coil of a
                              > > multi-turn wire
                              > > loop ?
                              > >
                              > > Corky
                              > >
                              > >
                              > >
                              > >
                              > > ------------------------------------
                              > >
                              > > If you've got links, post them in the Links section!
                              > > http://groups.yahoo.com/group/loopantennas/links
                              > >
                              > > Post files here. If the file comes from a website, please put it in the Links rather than uploading the file.
                              > > http://groups.yahoo.com/group/loopantennas/files
                              > >
                              > > You can now view images at higher resolution in Photos. Upload JPG and GIF into Photos. Please convert BMP or TIF to JPG or GIF before uploading.
                              > > http://ph.groups.yahoo.com/group/loopantennas/photos
                              > >
                              > > And please trim all this when replying!Yahoo! Groups Links
                              > >
                              > >
                              > >
                              >
                              >
                              > [Non-text portions of this message have been removed]
                              >
                            • skyspeed77
                              I do have a very noisy local with conjested apartments and 6 transformers within site of the front of the building. However, I m free to use the building
                              Message 14 of 20 , Jan 24, 2011
                                I do have a very noisy local with conjested apartments and 6 transformers within site of the front of the building.
                                However, I'm free to use the building anyway I want for antennas.
                                Corky

                                --- In loopantennas@yahoogroups.com, "longjohn119" <some_oil_with_your_teaparty@...> wrote:
                                >
                                > Chris has a newer design too he posted in the file section of the Group that looks promising but I haven't tried it myself yet (Waiting until I need other parts to justify ordering the MPS6521 transistors) He uses his patented (literally) augmentation technique on the 4 main transistors.
                                >
                                > http://groups.yahoo.com/group/loopantennas/files/
                                >
                                > Last file in the list
                                >
                                > JR
                                >
                                > --- In loopantennas@yahoogroups.com, "longjohn119" <some_oil_with_your_teaparty@> wrote:
                                > >
                                > > Chris Trask has a couple of tuned and untuned loop designs. Don't discount the active short verticals either, unless you have a specific noise source you need to null they are just as quiet as an active loop if you get them out in the open.
                                > >
                                > > http://home.earthlink.net/~christrask/
                                > >
                                > > Down at the bottom of the page but don't overlook the other stuff he has there, especially his work on augmented amps and mixers, and the stuff on transistor evaluations.
                                > >
                                > > JR
                                > >
                                > > --- In loopantennas@yahoogroups.com, "skyspeed77" <skyspeed77@> wrote:
                                > > >
                                > > > Has anyone reverse engineered the Wellbrook Loop and setup a similar
                                > > > DIY formula for building your own, perhaps of copper tubing ?
                                > > >
                                > > > Also a schematic for an amp to match that performance quality, or a
                                > > > commercially available one ?
                                > > >
                                > > > Later I have some questions about wire loops with variable caps, which I've been studying seriously and gathering components.
                                > > >
                                > > > I'm an SWL with a current interest in the AM band, but will likely go back to shortwave soon.
                                > > > My listening location is poor but I haver access to a second story roof. Poor means a building twice the height to the West and main street with lots of visable transformers on the power poles, first floor location, about 100 feet back from the power poles. I'm in L.A.
                                > > > and also have some interest in DXing the Tropic Bands.
                                > > >
                                > >
                                >
                              • Nota Real
                                Maybe the RH PRO-1A could be easier to reverse engineer ? According to tests it seems to be working better than Wellbrooks. If someone who has this antenna
                                Message 15 of 20 , Mar 4, 2011
                                  Maybe the RH PRO-1A could be easier to reverse engineer ?
                                  According to tests it seems to be working better than Wellbrooks.
                                  If someone who has this antenna could take some photos from inside
                                  the antenna junction box and preamplifier etc ?
                                  How many loop wires is there inside the aluminium tube etc.
                                  BR

                                  > To: loopantennas@yahoogroups.com
                                  > From: skyspeed77@...
                                  > Date: Tue, 18 Jan 2011 04:45:51 +0000
                                  > Subject: [loopantennas] WELLBROOK DIY
                                  >
                                  > Has anyone reverse engineered the Wellbrook Loop and setup a similar
                                  > DIY formula for building your own, perhaps of copper tubing ?
                                  >
                                  > Also a schematic for an amp to match that performance quality, or a
                                  > commercially available one ?
                                  >
                                  > Later I have some questions about wire loops with variable caps, which I've been studying seriously and gathering components.
                                  >
                                  > I'm an SWL with a current interest in the AM band, but will likely go back to shortwave soon.
                                  > My listening location is poor but I haver access to a second story roof. Poor means a building twice the height to the West and main street with lots of visable transformers on the power poles, first floor location, about 100 feet back from the power poles. I'm in L.A.
                                  > and also have some interest in DXing the Tropic Bands.
                                  >
                                  >
                                  >
                                  > ------------------------------------
                                  >
                                  > If you've got links, post them in the Links section!
                                  > http://groups.yahoo.com/group/loopantennas/links
                                  >
                                  > Post files here. If the file comes from a website, please put it in the Links rather than uploading the file.
                                  > http://groups.yahoo.com/group/loopantennas/files
                                  >
                                  > You can now view images at higher resolution in Photos. Upload JPG and GIF into Photos. Please convert BMP or TIF to JPG or GIF before uploading.
                                  > http://ph.groups.yahoo.com/group/loopantennas/photos
                                  >
                                  > And please trim all this when replying!Yahoo! Groups Links
                                  >
                                  >
                                  >


                                  [Non-text portions of this message have been removed]
                                • lexluthor6969
                                  I ve had one of these Pixel beauties for some time and have spent some time looking under the hood. This is definitely not something that is easily reversed
                                  Message 16 of 20 , Mar 8, 2011
                                    I ve had one of these Pixel beauties for some time and have spent some time looking under the hood. This is definitely not something that is easily reversed engineered and not something I would recommend for a DIY project. First of all the 30 dB preamp is very complex and has many transistors, tuning adjustments and exotic hard to get parts in it that are not readily available off the shelf. It has a very low noise figure and world–class intermod specs (OIP3 near 50 dBm and OIP3 over 110 dBm) that are much better than any receiver I've ever seen. There is nothing like this commercially available at a reasonable price. The one I have also has some very expensive Litz wire inside the tubing that is also hard to get. I would recommend that you search the posts by Chris Trask on this board. He has some schematics posted and some plans for a Moebius loop. While you won't get the "Ferrari" performance of the Pixel loop a "Ford" may get you to the same place.


                                    Initially I saw the Pixel antenna demonstrated at a local Ham show and was quite impressed with it. They had it setup indoors under some arc lights that were in the convention hall that also had a metal roof. This was probably the worst place possible to demonstrate an antenna. They did an A/B comparison against an active dipole antenna that MFJ sells. The results were simply amazing. The loop was able to achieve crystal clear reception while the active dipole was swamped with noise from the nearby arc lamps across most bands.

                                    I purchased one and when I got it setup I was not disappointed. It was much more quite than any antenna I have ever tried. (and I have tried many in my restricted location including a k9ay loop). The local noise from my neighbor's plasma TV and the local power line crude were greatly reduced or completely gone. I'm hearing stations I've never heard before. I'm a very happy camper and for $400 I consider it a great value.

                                    Relative to the build quality and weather resistance, I was actually quite impressed (unlike some others.) I pulled off some of the covers on the preamp and loop and it looks like all of the circuit boards and electrical connections are conformal coated and all of the mechanical joints and fittings were hermetically sealed with silicone or rubber gaskets.

                                    The outdoor preamp is in a nice die cast aluminum enclosure and is painted white to reduce solar heating in hot climates. (A nice touch for my location.) Also all of the required hardware, jumpers, adapters and cables for mounting and installation were included. They use rivets to attach and secure the aluminum tubes, but to me they seem very sturdy, electrically sound and mechanically robust.

                                    Lex


                                    --- In loopantennas@yahoogroups.com, Nota Real <not_a_real@...> wrote:
                                    >
                                    >
                                    > Maybe the RH PRO-1A could be easier to reverse engineer ?
                                    > According to tests it seems to be working better than Wellbrooks.
                                    > If someone who has this antenna could take some photos from inside
                                    > the antenna junction box and preamplifier etc ?
                                    > How many loop wires is there inside the aluminium tube etc.
                                    > BR
                                    >
                                    > > To: loopantennas@yahoogroups.com
                                    > > From: skyspeed77@...
                                    > > Date: Tue, 18 Jan 2011 04:45:51 +0000
                                    > > Subject: [loopantennas] WELLBROOK DIY
                                    > >
                                    > > Has anyone reverse engineered the Wellbrook Loop and setup a similar
                                    > > DIY formula for building your own, perhaps of copper tubing ?
                                    > >
                                    > > Also a schematic for an amp to match that performance quality, or a
                                    > > commercially available one ?
                                    > >
                                    > > Later I have some questions about wire loops with variable caps, which I've been studying seriously and gathering components.
                                    > >
                                    > > I'm an SWL with a current interest in the AM band, but will likely go back to shortwave soon.
                                    > > My listening location is poor but I haver access to a second story roof. Poor means a building twice the height to the West and main street with lots of visable transformers on the power poles, first floor location, about 100 feet back from the power poles. I'm in L.A.
                                    > > and also have some interest in DXing the Tropic Bands.
                                    > >
                                    > >
                                    > >
                                    > > ------------------------------------
                                    > >
                                    > > If you've got links, post them in the Links section!
                                    > > http://groups.yahoo.com/group/loopantennas/links
                                    > >
                                    > > Post files here. If the file comes from a website, please put it in the Links rather than uploading the file.
                                    > > http://groups.yahoo.com/group/loopantennas/files
                                    > >
                                    > > You can now view images at higher resolution in Photos. Upload JPG and GIF into Photos. Please convert BMP or TIF to JPG or GIF before uploading.
                                    > > http://ph.groups.yahoo.com/group/loopantennas/photos
                                    > >
                                    > > And please trim all this when replying!Yahoo! Groups Links
                                    > >
                                    > >
                                    > >
                                    >
                                    >
                                    > [Non-text portions of this message have been removed]
                                    >
                                  • Stephan Schaa
                                    This test sounds much like an advertisement. Are you working for or at Pixel Technologies?? Stephan _____ Von: loopantennas@yahoogroups.com
                                    Message 17 of 20 , Mar 9, 2011
                                      This test sounds much like an advertisement. Are you working for or at Pixel
                                      Technologies??

                                      Stephan




                                      _____

                                      Von: loopantennas@yahoogroups.com [mailto:loopantennas@yahoogroups.com] Im
                                      Auftrag von lexluthor6969
                                      Gesendet: Mittwoch, 9. März 2011 01:45
                                      An: loopantennas@yahoogroups.com
                                      Betreff: [loopantennas] Re: WELLBROOK DIY or Pixel Technologies RF PRO-1A




                                      I ve had one of these Pixel beauties for some time and have spent some time
                                      looking under the hood. This is definitely not something that is easily
                                      reversed engineered and not something I would recommend for a DIY project.
                                      First of all the 30 dB preamp is very complex and has many transistors,
                                      tuning adjustments and exotic hard to get parts in it that are not readily
                                      available off the shelf. It has a very low noise figure and world–class
                                      intermod specs (OIP3 near 50 dBm and OIP3 over 110 dBm) that are much better
                                      than any receiver I've ever seen. There is nothing like this commercially
                                      available at a reasonable price. The one I have also has some very expensive
                                      Litz wire inside the tubing that is also hard to get. I would recommend that
                                      you search the posts by Chris Trask on this board. He has some schematics
                                      posted and some plans for a Moebius loop. While you won't get the "Ferrari"
                                      performance of the Pixel loop a "Ford" may get you to the same place.

                                      Initially I saw the Pixel antenna demonstrated at a local Ham show and was
                                      quite impressed with it. They had it setup indoors under some arc lights
                                      that were in the convention hall that also had a metal roof. This was
                                      probably the worst place possible to demonstrate an antenna. They did an A/B
                                      comparison against an active dipole antenna that MFJ sells. The results were
                                      simply amazing. The loop was able to achieve crystal clear reception while
                                      the active dipole was swamped with noise from the nearby arc lamps across
                                      most bands.

                                      I purchased one and when I got it setup I was not disappointed. It was much
                                      more quite than any antenna I have ever tried. (and I have tried many in my
                                      restricted location including a k9ay loop). The local noise from my
                                      neighbor's plasma TV and the local power line crude were greatly reduced or
                                      completely gone. I'm hearing stations I've never heard before. I'm a very
                                      happy camper and for $400 I consider it a great value.

                                      Relative to the build quality and weather resistance, I was actually quite
                                      impressed (unlike some others.) I pulled off some of the covers on the
                                      preamp and loop and it looks like all of the circuit boards and electrical
                                      connections are conformal coated and all of the mechanical joints and
                                      fittings were hermetically sealed with silicone or rubber gaskets.

                                      The outdoor preamp is in a nice die cast aluminum enclosure and is painted
                                      white to reduce solar heating in hot climates. (A nice touch for my
                                      location.) Also all of the required hardware, jumpers, adapters and cables
                                      for mounting and installation were included. They use rivets to attach and
                                      secure the aluminum tubes, but to me they seem very sturdy, electrically
                                      sound and mechanically robust.

                                      Lex

                                      --- In loopantennas@yahoogroups.com <mailto:loopantennas%40yahoogroups.com>
                                      , Nota Real <not_a_real@...> wrote:
                                      >
                                      >
                                      > Maybe the RH PRO-1A could be easier to reverse engineer ?
                                      > According to tests it seems to be working better than Wellbrooks.
                                      > If someone who has this antenna could take some photos from inside
                                      > the antenna junction box and preamplifier etc ?
                                      > How many loop wires is there inside the aluminium tube etc.
                                      > BR
                                      >
                                      > > To: loopantennas@yahoogroups.com <mailto:loopantennas%40yahoogroups.com>

                                      > > From: skyspeed77@...
                                      > > Date: Tue, 18 Jan 2011 04:45:51 +0000
                                      > > Subject: [loopantennas] WELLBROOK DIY
                                      > >
                                      > > Has anyone reverse engineered the Wellbrook Loop and setup a similar
                                      > > DIY formula for building your own, perhaps of copper tubing ?
                                      > >
                                      > > Also a schematic for an amp to match that performance quality, or a
                                      > > commercially available one ?
                                      > >
                                      > > Later I have some questions about wire loops with variable caps, which
                                      I've been studying seriously and gathering components.
                                      > >
                                      > > I'm an SWL with a current interest in the AM band, but will likely go
                                      back to shortwave soon.
                                      > > My listening location is poor but I haver access to a second story roof.
                                      Poor means a building twice the height to the West and main street with lots
                                      of visable transformers on the power poles, first floor location, about 100
                                      feet back from the power poles. I'm in L.A.
                                      > > and also have some interest in DXing the Tropic Bands.
                                      > >
                                      > >
                                      > >
                                      > > ------------------------------------
                                      > >
                                      > > If you've got links, post them in the Links section!
                                      > > http://groups.yahoo.com/group/loopantennas/links
                                      > >
                                      > > Post files here. If the file comes from a website, please put it in the
                                      Links rather than uploading the file.
                                      > > http://groups.yahoo.com/group/loopantennas/files
                                      > >
                                      > > You can now view images at higher resolution in Photos. Upload JPG and
                                      GIF into Photos. Please convert BMP or TIF to JPG or GIF before uploading.
                                      > > http://ph.groups.yahoo.com/group/loopantennas/photos
                                      > >
                                      > > And please trim all this when replying!Yahoo! Groups Links
                                      > >
                                      > >
                                      > >
                                      >
                                      >
                                      > [Non-text portions of this message have been removed]
                                      >




                                      _____


                                      eMail ist virenfrei.
                                      Von AVG überprüft - www.avg.de
                                      Version: 10.0.1204 / Virendatenbank: 1435/3492 - Ausgabedatum: 08.03.2011



                                      [Non-text portions of this message have been removed]
                                    • lexluthor6969
                                      Stephan: i have no affiliation with Pixel. Just a very happy customer. It solved some problems that I haven t been able to solve with any other antenna. You
                                      Message 18 of 20 , Mar 11, 2011
                                        Stephan:
                                        i have no affiliation with Pixel. Just a very happy customer. It solved some problems that I haven't been able to solve with any other antenna. You might want to look at the reviews of this antenna on e-ham.net. Lots of others have found this antenna a great performer as well.

                                        Lex

                                        --- In loopantennas@yahoogroups.com, "Stephan Schaa" <schaa@...> wrote:
                                        >
                                        > This test sounds much like an advertisement. Are you working for or at Pixel
                                        > Technologies??
                                        >
                                        > Stephan
                                        >
                                        >
                                        >
                                        >
                                        > _____
                                        >
                                        > Von: loopantennas@yahoogroups.com [mailto:loopantennas@yahoogroups.com] Im
                                        > Auftrag von lexluthor6969
                                        > Gesendet: Mittwoch, 9. März 2011 01:45
                                        > An: loopantennas@yahoogroups.com
                                        > Betreff: [loopantennas] Re: WELLBROOK DIY or Pixel Technologies RF PRO-1A
                                        >
                                        >
                                        >
                                        >
                                        > I ve had one of these Pixel beauties for some time and have spent some time
                                        > looking under the hood. This is definitely not something that is easily
                                        > reversed engineered and not something I would recommend for a DIY project.
                                        > First of all the 30 dB preamp is very complex and has many transistors,
                                        > tuning adjustments and exotic hard to get parts in it that are not readily
                                        > available off the shelf. It has a very low noise figure and world–class
                                        > intermod specs (OIP3 near 50 dBm and OIP3 over 110 dBm) that are much better
                                        > than any receiver I've ever seen. There is nothing like this commercially
                                        > available at a reasonable price. The one I have also has some very expensive
                                        > Litz wire inside the tubing that is also hard to get. I would recommend that
                                        > you search the posts by Chris Trask on this board. He has some schematics
                                        > posted and some plans for a Moebius loop. While you won't get the "Ferrari"
                                        > performance of the Pixel loop a "Ford" may get you to the same place.
                                        >
                                        > Initially I saw the Pixel antenna demonstrated at a local Ham show and was
                                        > quite impressed with it. They had it setup indoors under some arc lights
                                        > that were in the convention hall that also had a metal roof. This was
                                        > probably the worst place possible to demonstrate an antenna. They did an A/B
                                        > comparison against an active dipole antenna that MFJ sells. The results were
                                        > simply amazing. The loop was able to achieve crystal clear reception while
                                        > the active dipole was swamped with noise from the nearby arc lamps across
                                        > most bands.
                                        >
                                        > I purchased one and when I got it setup I was not disappointed. It was much
                                        > more quite than any antenna I have ever tried. (and I have tried many in my
                                        > restricted location including a k9ay loop). The local noise from my
                                        > neighbor's plasma TV and the local power line crude were greatly reduced or
                                        > completely gone. I'm hearing stations I've never heard before. I'm a very
                                        > happy camper and for $400 I consider it a great value.
                                        >
                                        > Relative to the build quality and weather resistance, I was actually quite
                                        > impressed (unlike some others.) I pulled off some of the covers on the
                                        > preamp and loop and it looks like all of the circuit boards and electrical
                                        > connections are conformal coated and all of the mechanical joints and
                                        > fittings were hermetically sealed with silicone or rubber gaskets.
                                        >
                                        > The outdoor preamp is in a nice die cast aluminum enclosure and is painted
                                        > white to reduce solar heating in hot climates. (A nice touch for my
                                        > location.) Also all of the required hardware, jumpers, adapters and cables
                                        > for mounting and installation were included. They use rivets to attach and
                                        > secure the aluminum tubes, but to me they seem very sturdy, electrically
                                        > sound and mechanically robust.
                                        >
                                        > Lex
                                        >
                                        > --- In loopantennas@yahoogroups.com <mailto:loopantennas%40yahoogroups.com>
                                        > , Nota Real <not_a_real@> wrote:
                                        > >
                                        > >
                                        > > Maybe the RH PRO-1A could be easier to reverse engineer ?
                                        > > According to tests it seems to be working better than Wellbrooks.
                                        > > If someone who has this antenna could take some photos from inside
                                        > > the antenna junction box and preamplifier etc ?
                                        > > How many loop wires is there inside the aluminium tube etc.
                                        > > BR
                                        > >
                                        > > > To: loopantennas@yahoogroups.com <mailto:loopantennas%40yahoogroups.com>
                                        >
                                        > > > From: skyspeed77@
                                        > > > Date: Tue, 18 Jan 2011 04:45:51 +0000
                                        > > > Subject: [loopantennas] WELLBROOK DIY
                                        > > >
                                        > > > Has anyone reverse engineered the Wellbrook Loop and setup a similar
                                        > > > DIY formula for building your own, perhaps of copper tubing ?
                                        > > >
                                        > > > Also a schematic for an amp to match that performance quality, or a
                                        > > > commercially available one ?
                                        > > >
                                        > > > Later I have some questions about wire loops with variable caps, which
                                        > I've been studying seriously and gathering components.
                                        > > >
                                        > > > I'm an SWL with a current interest in the AM band, but will likely go
                                        > back to shortwave soon.
                                        > > > My listening location is poor but I haver access to a second story roof.
                                        > Poor means a building twice the height to the West and main street with lots
                                        > of visable transformers on the power poles, first floor location, about 100
                                        > feet back from the power poles. I'm in L.A.
                                        > > > and also have some interest in DXing the Tropic Bands.
                                        > > >
                                        > > >
                                        > > >
                                        > > > ------------------------------------
                                        > > >
                                        > > > If you've got links, post them in the Links section!
                                        > > > http://groups.yahoo.com/group/loopantennas/links
                                        > > >
                                        > > > Post files here. If the file comes from a website, please put it in the
                                        > Links rather than uploading the file.
                                        > > > http://groups.yahoo.com/group/loopantennas/files
                                        > > >
                                        > > > You can now view images at higher resolution in Photos. Upload JPG and
                                        > GIF into Photos. Please convert BMP or TIF to JPG or GIF before uploading.
                                        > > > http://ph.groups.yahoo.com/group/loopantennas/photos
                                        > > >
                                        > > > And please trim all this when replying!Yahoo! Groups Links
                                        > > >
                                        > > >
                                        > > >
                                        > >
                                        > >
                                        > > [Non-text portions of this message have been removed]
                                        > >
                                        >
                                        >
                                        >
                                        >
                                        > _____
                                        >
                                        >
                                        > eMail ist virenfrei.
                                        > Von AVG überprüft - www.avg.de
                                        > Version: 10.0.1204 / Virendatenbank: 1435/3492 - Ausgabedatum: 08.03.2011
                                        >
                                        >
                                        >
                                        > [Non-text portions of this message have been removed]
                                        >
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