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Re: Wellbrook construction
Patrick Reynaert
Hi,
the wellbrook is not a shielded antenna, the Aluminium tube is the actual antenna. Shielding (with a gap of course) a loop only shields it from electrical noise at very low frequecies, i.e. at frequencies where the shield thickness is less than the skin depth. At higher frequencies, where the shield is thicker than the skin depth, the shield only helps to get a better balance, and hence a better 'null' in the reception pattern. Patrick. Hue Miller <kargo_cult@...> wrote: Wellbrook antenna: is the loop shielded? I am guessing maybe not, since its performance still seems to be good into the VHF range. IF not - will shielding such a loop, be worthwhile to diminish electrical field noise? I am thinking a "Hula Hoop" toy might be a basis for a homemade loop. Cut open the loop, feed wire thru it, and glue back together. Maybe with aluminum foil wrapped around the thing, for shielding, and amplifier module attached right to the loop. WL1030 page - i very much look forward to reading the material there. I just wonder why it is necessary to "register". What is the thinking behind that? -Hue Miller If you've got links, post them in the Links section! Post files here. If the file comes from a website, please put it in the Links rather than uploading the file. 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. And please trim all this when replying! Yahoo! Groups Links --------------------------------- Food fight? Enjoy some healthy debate in the Yahoo! Answers Food & Drink Q&A. |
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Re: Wellbrook construction
In a message dated 14/05/2007 21:08:36 GMT Daylight Time,
christrask@... writes: Patrick is absolutely correct in stating that the aluminum shield (aka the outer conductor)is the actual antenna. This is the manner in which shielded loops function at their operating frequency. At very low frequencies where most electrical field noise exists, the currents and voltages of both arms of the outer conductor are equal in both potential and polarity (provided the gap is at the exact centre), with the currents being the same on both surfaces of the outer conductor material and zero at the gap. The currents that are coupled to the inner conductor(s) cancel so that there is no net noise current delivered to the receiver. ------------------------------------- Hi Chris The Wellbrook isn't a shielded loop antenna. There no gap in this loop, other than inside the housing at the bottom where it connects to the amp. regards Nigel GM8PZR |
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Re: Wellbrook construction
In a message dated 14/05/2007 20:21:50 GMT Daylight Time,
rmoore5@... writes: You are wrong that the Aluminim is the actual antenna. There are wires inside of it and it is only there as a mechanical support. I know this because I've removed the potting material from one of these to find out. This can also be verified by examining the 5030. It is a semi-ridgid version of the ALA-1530. Rob ---------------------------------- Hi Rob Are you sure re the 1530? Certainly it's true for the 5030 as that's got a plastic tube, and I can hear the wire rattling around inside it as I'd expect, but I've never heard anything rattling inside the 1530. I would expect that you'd see wires going to the potted amp, even if the tube is the antenna, as the tube will likely mechanically terminate inside the plastic entry tubes on the electrical junction box used as a housing with perhaps a screw and solder tag connection at the ends. regards Nigel GM8PZR |
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Re: RF Systems DX-One Pro MkII - Bi-Loop or not ?
Fraser
--- In loopantennas@..., "Steve Ratzlaff"
<steveratz@...> wrote: DX-1 Pro, and the receiver coupler/supply.circuit is an exact clone of the old Ralph Burhans circuit he published backin the 1980's, using 100% negative feedback.(SNIPPED) Hi Steve, Many thanks for that superb description of the DX-1. You have made my day as I have been scratching my head about this antennas design for ages. When I X-Rayed the mast section it had four wires interconnecting the various 'loop' arms but I couldn't be sure how they were connected. They certainly are not all wired in parallel in the MKII. I was wondering if they had wired the 'loop' arms in series to effectively compress a long whip into a small space. This bit of the design still eludes me. As for the amplifier... your information is invaluable. The MKII amplifier is stated as providing 10dB gain whereas the MKI was spec'ed at 6dB gain. The issue of input capacitance is very interesting indeed. I have some NOS Motorola high power jFETs (or tFETS ?) that were used in some Watkins Johnson amplifiers that I maintained. I suspect that these will also exhibit higher than desirable input capacitance so I will re think using them in any antenna designs that I build. Thank you for your excellent help with this question Steve. It does, however, lead me to wonder about RF Systems performance claims. RFS make the MLB1 and this has caused much discussion both positive and negative. I like their AA-150 that was built for the Lowe HF-150 but it may be no better than any other active whip on the market. It is well built though. The DX-10 is basically an AA-150 in a different shell. As for the passive HF magnetic whips and some of their other exotic designs, I am not sure that these are not just well engineered 'snake oil' antennas. I own an RF Systems DX-500 which is beautifully constructed and claims to work upto 500 MHz. I have found that it needs an excellent groundplane for HF work and is really just an RF probe (it has an extremely short active element). Oh well.... it looks like the DX-1 is just an exotic & expensive active whip pretending to be a loop then :-( Thanks to everyone for their input on this topic. I'm off to start saving for a Wellbrook ALA1530+. Fraser |
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Re: RF Systems DX-One Pro MkII - Bi-Loop or not ?
Steve Ratzlaff
As a postscript to the RF Systems DX-1 Pro active whip antenna comments I made, WRTH did an extensive review of various active whip antennas perhaps 5 or more years ago. The DX-1 Pro was clearly identified as an active whip antenna then, and was one of the antennas reviewed--it had a good review rating. The newer "MK II" apparently is a recent variation of that same active whip antenna. Perhaps the addition of a common-mode choke on the output of the whipamp is the only change, as I suggested in my previous post.
73, Steve |
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Re: RF Systems DX-One Pro MkII - Bi-Loop or not ?
Steve Ratzlaff
Hi,
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I'm familiar with the circuits used in the head end of the older DX-1 Pro, and the receiver coupler/supply. The head end is a basic high-impedance active whip antenna. The circuit is an exact clone of the old Ralph Burhans circuit he published back in the 1980's, using 100% negative feedback. That would account for one of the transformers noted by Fraser. The other transformer is very likely a common-mode choke on the output. My older unit did not have that common-mode choke; it only had the one feedback transformer. I'm guessing the "MK II" means the common-mode choke addition was the only improvement from the original DX-1 Pro. The active power jfet device RF Systems is using has significant gate-source capacitance, which acts to shunt signals to ground the higher you go in frequency, and loss in sensitivity begins from about 12 MHz and up. They devised the very elaborate "egg beater" cage whip antenna in an attempt to improve the antenna capacitance, to offset the active device shunting effect. The bit in the advertising about reducing polarization effects is purely smoke and mirrors nonsense, and has no effect whatsoever on various signal polarization being received better with that cage whip antenna. There is no voltage gain for this active amplifier circuit, only overall loss from input to output. The receiver coupler's "+10dB" input position is also a piece of fiction. That position directly couples the antenna's output through the various other parts (switchable BCB filter and dual-output splitter) to the output to the receiver. The other positions, "0" to "-40" are all switched attenuators before going to the BCB filter and splitter, with the "0" position being either -3 dB or -6 dB attenuation ( I forget which). The BCB filter is not designed for the NA BCB frequency range but for Europe. The active device is very similar to the Crystalonics CP650 power jfet device that Dallas Lankford first discovered would work well in the old Burhans active whip circuit--it too has significant gate-source input capacitance. (This is the device the AMRAD active whip is using; they got their circuit from Dallas Lankford, who was never given proper credit in the article.) I have been building and experimenting with active whip antennas for a number of years now; I've tested just about every commercially available antenna on the market, from either a hobby standpoint or from when my old company was building active antennas as a Defense Contractor. The DX-1 Pro is the only commercially available antenna that I've tried that I would recommend, despite its increasing loss of sensitivity as you go up the HF frequency range. However, it's very expensive for most hobbyists to even consider purchasing one. And any active antenna performs only as well as the local noise environment it's used in, and of course must be used externally from any dwelling with AC power. The farther from AC power you can mount such an antenna, either horizontal or vertical distance from AC power, the better it can work without being limited by local AC noise. 73, Steve ----- Original Message -----
From: "Fraser" <fraser.castle@...> To: <loopantennas@...> Sent: Sunday, May 13, 2007 4:29 AM Subject: [loopantennas] RF Systems DX-One Pro MkII - Bi-Loop or not ? Hi All, |
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Wellbrook construction
Wellbrook antenna: is the loop shielded? I am guessing maybe not,
since its performance still seems to be good into the VHF range. IF not - will shielding such a loop, be worthwhile to diminish electrical field noise? I am thinking a "Hula Hoop" toy might be a basis for a homemade loop. Cut open the loop, feed wire thru it, and glue back together. Maybe with aluminum foil wrapped around the thing, for shielding, and amplifier module attached right to the loop. WL1030 page - i very much look forward to reading the material there. I just wonder why it is necessary to "register". What is the thinking behind that? -Hue Miller |
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Re: RF Systems DX-One Pro MkII - Bi-Loop or not ?
Dear Fraser
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In this case for direct feedthru I guess I un-tract my retraction (LOL again) smells like a Norton amp with this gain range ie 8 to 12 although with higher turns can get to near 20 however 10 is a clue to the noiseless Norton amp in my opinion (not to say other configurations will not end up something like this, such as a grounded base bipolar perhaps optimized for low noise) xrays might prove interesting best Paul ----- Original Message ----
From: Fraser <fraser.castle@...> To: loopantennas@... Sent: Sunday, May 13, 2007 4:09:03 PM Subject: [loopantennas] Re: RF Systems DX-One Pro MkII - Bi-Loop or not ? --- In loopantennas@ yahoogroups. com, Paul Birke <nonlinear@. ..> wrote: Hi Fraser and All sorry scratch all that I just transmitted the 10 dB is the antenna alone LOL oh well Paul Hi Paul, Thanks for the input. The DX-One base unit has unusual calibrations on the attenuator. Instead of just showing the inserted attenuation it shows the system gain. The +10dB position is a straight through connection and is described as +10dB because the antenna head is stated as having a gain of 10 dB. The 0dB position on the base unit is actually an insertion of 10dB attenuation. Theoreticaly in this position the input to the receiver splitter is the same as the signal strength at the antenna elements without any gain. This does not take account of feeder losses though. The base unit is a work of art. It's a very solid affair and contains a low noise 28 Volt d.c regulated power supply, a calibrated stepped attenuator, A MW filter and a high quality splitter. I bought a couple of extra base units from Lowe(UK) last year for ?20 each. They are easy to convert to 12V output and work very well with any phantom powered active antennas. I will have to look out the X-Rays that I took of the Head unit electronics as they may be of interest. I note that the review that I refered to states that the DX-One requires an excellent ground plane. I have the DX-One MKII and the only groundplane requirement detailed in the instructions is for static discharge purposes. The same is not true of my RFS DX-500 which requires an excellent groundplane to perform well. Fraser <!-- #ygrp-mlmsg {font-size:13px;font-family:arial, helvetica, clean, sans-serif;} #ygrp-mlmsg table {font-size:inherit;font:100%;} #ygrp-mlmsg select, input, textarea {font:99% arial, helvetica, clean, sans-serif;} #ygrp-mlmsg pre, code {font:115% monospace;} #ygrp-mlmsg * {line-height:1.22em;} #ygrp-text{ font-family:Georgia; } #ygrp-text p{ margin:0 0 1em 0;} #ygrp-tpmsgs{ font-family:Arial; clear:both;} #ygrp-vitnav{ padding-top:10px;font-family:Verdana;font-size:77%;margin:0;} #ygrp-vitnav a{ padding:0 1px;} #ygrp-actbar{ clear:both;margin:25px 0;white-space:nowrap;color:#666;text-align:right;} #ygrp-actbar .left{ float:left;white-space:nowrap;} .bld{font-weight:bold;} #ygrp-grft{ font-family:Verdana;font-size:77%;padding:15px 0;} #ygrp-ft{ font-family:verdana;font-size:77%;border-top:1px solid #666; padding:5px 0; } #ygrp-mlmsg #logo{ padding-bottom:10px;} #ygrp-vital{ background-color:#e0ecee;margin-bottom:20px;padding:2px 0 8px 8px;} #ygrp-vital #vithd{ font-size:77%;font-family:Verdana;font-weight:bold;color:#333;text-transform:uppercase;} #ygrp-vital ul{ padding:0;margin:2px 0;} #ygrp-vital ul li{ list-style-type:none;clear:both;border:1px solid #e0ecee; } #ygrp-vital ul li .ct{ font-weight:bold;color:#ff7900;float:right;width:2em;text-align:right;padding-right:.5em;} #ygrp-vital ul li .cat{ font-weight:bold;} #ygrp-vital a { text-decoration:none;} #ygrp-vital a:hover{ text-decoration:underline;} #ygrp-sponsor #hd{ color:#999;font-size:77%;} #ygrp-sponsor #ov{ padding:6px 13px;background-color:#e0ecee;margin-bottom:20px;} #ygrp-sponsor #ov ul{ padding:0 0 0 8px;margin:0;} #ygrp-sponsor #ov li{ list-style-type:square;padding:6px 0;font-size:77%;} #ygrp-sponsor #ov li a{ text-decoration:none;font-size:130%;} #ygrp-sponsor #nc { background-color:#eee;margin-bottom:20px;padding:0 8px;} #ygrp-sponsor .ad{ padding:8px 0;} #ygrp-sponsor .ad #hd1{ font-family:Arial;font-weight:bold;color:#628c2a;font-size:100%;line-height:122%;} #ygrp-sponsor .ad a{ text-decoration:none;} #ygrp-sponsor .ad a:hover{ text-decoration:underline;} #ygrp-sponsor .ad p{ margin:0;} o {font-size:0;} .MsoNormal { margin:0 0 0 0;} #ygrp-text tt{ font-size:120%;} blockquote{margin:0 0 0 4px;} .replbq {margin:4;} --> [Non-text portions of this message have been removed] |
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Re: RF Systems DX-One Pro MkII - Bi-Loop or not ?
Fraser
--- In loopantennas@..., Paul Birke <nonlinear@...> wrote:
Hi Paul, Thanks for the input. The DX-One base unit has unusual calibrations on the attenuator. Instead of just showing the inserted attenuation it shows the system gain. The +10dB position is a straight through connection and is described as +10dB because the antenna head is stated as having a gain of 10 dB. The 0dB position on the base unit is actually an insertion of 10dB attenuation. Theoreticaly in this position the input to the receiver splitter is the same as the signal strength at the antenna elements without any gain. This does not take account of feeder losses though. The base unit is a work of art. It's a very solid affair and contains a low noise 28 Volt d.c regulated power supply, a calibrated stepped attenuator, A MW filter and a high quality splitter. I bought a couple of extra base units from Lowe(UK) last year for ?20 each. They are easy to convert to 12V output and work very well with any phantom powered active antennas. I will have to look out the X-Rays that I took of the Head unit electronics as they may be of interest. I note that the review that I refered to states that the DX-One requires an excellent ground plane. I have the DX-One MKII and the only groundplane requirement detailed in the instructions is for static discharge purposes. The same is not true of my RFS DX-500 which requires an excellent groundplane to perform well. Fraser |
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Re: RF Systems DX-One Pro MkII - Bi-Loop or not ?
Hi Fraser and All
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sorry scratch all that I just transmitted the 10 dB is the antenna alone LOL oh well Paul ----- Original Message ----
From: Paul Birke <nonlinear@...> To: loopantennas@... Sent: Sunday, May 13, 2007 12:00:04 PM Subject: Re: [loopantennas] Re: RF Systems DX-One Pro MkII - Bi-Loop or not ? Dear Fraser had a look and look at the specs I think there is a big clue in the gain as it is only 10 dB to me that indicates a David Norton Noiseless Amplifier and likely very close to what Dallas Lankford laid down in early 1990s the transformers here should be three [1] a centre-tapped input [2] the norton transformer [3] the output transformer one of these transformers is a toroid for sure ie the norton although this could be made as a binocular however either of [1] or [3] could be a mini-circuits plastic block just my take Paul V Birke PEng Guelph ON Canada ----- Original Message ---- From: Fraser <fraser.castle@ virgin.net> To: loopantennas@ yahoogroups. com Sent: Sunday, May 13, 2007 7:56:16 AM Subject: [loopantennas] Re: RF Systems DX-One Pro MkII - Bi-Loop or not ? CORRECTION.. ... --- In loopantennas@ yahoogroups. com, "Fraser" <fraser.castle@ ...> wrote: Ref the DX-One and "what is it" I see that Universal sell it so there web site gives a good view of it. I will upload the PDF instructions and specs to the files area for Group comment. Cheers Fraser OOOOPs, I forgot the url for Universal ! Here are some urls related to the DX-1 and a review :-) l-radio.com/ catalog/sw_ ant/1246. html systems.nl/ DX-one.html . at/DX_One. php and a review here.... . info/equipment/ dx1pro.dx fraser <!-- #ygrp-mlmsg {font-size:13px; font-family: arial, helvetica, clean, sans-serif;} #ygrp-mlmsg table {font-size:inherit; font:100% ;} #ygrp-mlmsg select, input, textarea {font:99% arial, helvetica, clean, sans-serif;} #ygrp-mlmsg pre, code {font:115% monospace;} #ygrp-mlmsg * {line-height: 1.22em;} #ygrp-text{ font-family: Georgia; } #ygrp-text p{ margin:0 0 1em 0;} #ygrp-tpmsgs{ font-family: Arial; clear:both;} #ygrp-vitnav{ padding-top: 10px;font- family:Verdana; font-size: 77%;margin: 0;} #ygrp-vitnav a{ padding:0 1px;} #ygrp-actbar{ clear:both;margin: 25px 0;white-space: nowrap;color: #666;text- align:right; } #ygrp-actbar .left{ float:left;white- space:nowrap; } .bld{font-weight: bold;} #ygrp-grft{ font-family: Verdana;font- size:77%; padding:15px 0;} #ygrp-ft{ font-family: verdana;font- size:77%; border-top: 1px solid #666; padding:5px 0; } #ygrp-mlmsg #logo{ padding-bottom: 10px;} #ygrp-vital{ background-color: #e0ecee;margin- bottom:20px; padding:2px 0 8px 8px;} #ygrp-vital #vithd{ font-size:77% ;font-family: Verdana;font- weight:bold; color:#333; text-transform: uppercase; } #ygrp-vital ul{ padding:0;margin: 2px 0;} #ygrp-vital ul li{ list-style-type: none;clear: both;border: 1px solid #e0ecee; } #ygrp-vital ul li .ct{ font-weight: bold;color: #ff7900;float: right;width: 2em;text- align:right; padding-right: .5em;} #ygrp-vital ul li .cat{ font-weight: bold;} #ygrp-vital a { text-decoration: none;} #ygrp-vital a:hover{ text-decoration: underline; } #ygrp-sponsor #hd{ color:#999;font- size:77%; } #ygrp-sponsor #ov{ padding:6px 13px;background- color:#e0ecee; margin-bottom: 20px;} #ygrp-sponsor #ov ul{ padding:0 0 0 8px;margin:0; } #ygrp-sponsor #ov li{ list-style-type: square;padding: 6px 0;font-size: 77%;} #ygrp-sponsor #ov li a{ text-decoration: none;font- size:130% ;} #ygrp-sponsor #nc { background-color: #eee;margin- bottom:20px; padding:0 8px;} #ygrp-sponsor .ad{ padding:8px 0;} #ygrp-sponsor .ad #hd1{ font-family: Arial;font- weight:bold; color:#628c2a; font-size: 100%;line- height:122% ;} #ygrp-sponsor .ad a{ text-decoration: none;} #ygrp-sponsor .ad a:hover{ text-decoration: underline; } #ygrp-sponsor .ad p{ margin:0;} o {font-size:0; } .MsoNormal { margin:0 0 0 0;} #ygrp-text tt{ font-size:120% ;} blockquote{margin: 0 0 0 4px;} .replbq {margin:4;} --> <!-- #ygrp-mlmsg {font-size:13px;font-family:arial, helvetica, clean, sans-serif;} #ygrp-mlmsg table {font-size:inherit;font:100%;} #ygrp-mlmsg select, input, textarea {font:99% arial, helvetica, clean, sans-serif;} #ygrp-mlmsg pre, code {font:115% monospace;} #ygrp-mlmsg * {line-height:1.22em;} #ygrp-text{ font-family:Georgia; } #ygrp-text p{ margin:0 0 1em 0;} #ygrp-tpmsgs{ font-family:Arial; clear:both;} #ygrp-vitnav{ padding-top:10px;font-family:Verdana;font-size:77%;margin:0;} #ygrp-vitnav a{ padding:0 1px;} #ygrp-actbar{ clear:both;margin:25px 0;white-space:nowrap;color:#666;text-align:right;} #ygrp-actbar .left{ float:left;white-space:nowrap;} .bld{font-weight:bold;} #ygrp-grft{ font-family:Verdana;font-size:77%;padding:15px 0;} #ygrp-ft{ font-family:verdana;font-size:77%;border-top:1px solid #666; padding:5px 0; } #ygrp-mlmsg #logo{ padding-bottom:10px;} #ygrp-vital{ background-color:#e0ecee;margin-bottom:20px;padding:2px 0 8px 8px;} #ygrp-vital #vithd{ font-size:77%;font-family:Verdana;font-weight:bold;color:#333;text-transform:uppercase;} #ygrp-vital ul{ padding:0;margin:2px 0;} #ygrp-vital ul li{ list-style-type:none;clear:both;border:1px solid #e0ecee; } #ygrp-vital ul li .ct{ font-weight:bold;color:#ff7900;float:right;width:2em;text-align:right;padding-right:.5em;} #ygrp-vital ul li .cat{ font-weight:bold;} #ygrp-vital a { text-decoration:none;} #ygrp-vital a:hover{ text-decoration:underline;} #ygrp-sponsor #hd{ color:#999;font-size:77%;} #ygrp-sponsor #ov{ padding:6px 13px;background-color:#e0ecee;margin-bottom:20px;} #ygrp-sponsor #ov ul{ padding:0 0 0 8px;margin:0;} #ygrp-sponsor #ov li{ list-style-type:square;padding:6px 0;font-size:77%;} #ygrp-sponsor #ov li a{ text-decoration:none;font-size:130%;} #ygrp-sponsor #nc { background-color:#eee;margin-bottom:20px;padding:0 8px;} #ygrp-sponsor .ad{ padding:8px 0;} #ygrp-sponsor .ad #hd1{ font-family:Arial;font-weight:bold;color:#628c2a;font-size:100%;line-height:122%;} #ygrp-sponsor .ad a{ text-decoration:none;} #ygrp-sponsor .ad a:hover{ text-decoration:underline;} #ygrp-sponsor .ad p{ margin:0;} o {font-size:0;} .MsoNormal { margin:0 0 0 0;} #ygrp-text tt{ font-size:120%;} blockquote{margin:0 0 0 4px;} .replbq {margin:4;} --> |
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Re: RF Systems DX-One Pro MkII - Bi-Loop or not ?
n2chi
Hi Fraser,
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I hadn't thought "polarization fading" to be a big problem, although a real phenomenom, else every antenna since Marconi would have been egg- shaped I'm thinking. I'm no expert, however. I'd guess the low noise comes from the quiet electronics and/or the loop aspect of the antenna, if it is a loop. Universal's write-up calls the antenna omnidirectional without regard to frequency, so that doesn't sound like a loop. The manufacturer's write up says their antenna is a "....combination of 2 loops, radials and a vertical receiving element." If the antenna is simply a vertical, I could imagine the loops performing a Yagi-like reflector function. But I don't think they would affect the polarization or phase. I guess that like most antennas, one has to A/B it with another to compare. Bring it over to my deck and we'll try it against my Wellbrook. Dave --- In loopantennas@..., "Fraser" <fraser.castle@...> wrote:
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Re: RF Systems DX-One Pro MkII - Bi-Loop or not ?
n2chi
Hi Fraser,
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Show quoted text
I hadn't thought "polarization fading" to be a big problem, although a real phenomenom, else every antenna since Marconi would have been egg- shaped I'm thinking. I'm no expert, however. I'd guess the low noise comes from the quiet electronics and/or the loop aspect of the antenna, if it is a loop. Universal's write-up calls the antenna omnidirectional without regard to frequency, so that doesn't sound like a loop. The manufacturer's write up says their antenna is a "....combination of 2 loops, radials and a vertical receiving element." If the antenna is simply a vertical, I could imagine the loops performing a Yagi-like reflector function. But I don't think they would affect the polarization or phase. I guess that like most antennas, one has to A/B it with another to compare. Bring it over to my deck and we'll try it against my Wellbrook. Dave --- In loopantennas@..., "Fraser" <fraser.castle@...> wrote:
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Re: RF Systems DX-One Pro MkII - Bi-Loop or not ?
Dear Fraser
toggle quoted message
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had a look and look at the specs I think there is a big clue in the gain as it is only 10 dB to me that indicates a David Norton Noiseless Amplifier and likely very close to what Dallas Lankford laid down in early 1990s the transformers here should be three [1] a centre-tapped input [2] the norton transformer [3] the output transformer one of these transformers is a toroid for sure ie the norton although this could be made as a binocular however either of [1] or [3] could be a mini-circuits plastic block just my take Paul V Birke PEng Guelph ON Canada ----- Original Message ----
From: Fraser <fraser.castle@...> To: loopantennas@... Sent: Sunday, May 13, 2007 7:56:16 AM Subject: [loopantennas] Re: RF Systems DX-One Pro MkII - Bi-Loop or not ? CORRECTION.. ... --- In loopantennas@ yahoogroups. com, "Fraser" <fraser.castle@ ...> wrote: Ref the DX-One and "what is it" I see that Universal sell it so there web site gives a good view ofit. I will upload the PDF instructions and specs to the files area for Group comment. Cheers Fraser OOOOPs, I forgot the url for Universal ! Here are some urls related to the DX-1 and a review :-) l-radio.com/ catalog/sw_ ant/1246. html systems.nl/ DX-one.html . at/DX_One. php and a review here.... . info/equipment/ dx1pro.dx fraser <!-- #ygrp-mlmsg {font-size:13px;font-family:arial, helvetica, clean, sans-serif;} #ygrp-mlmsg table {font-size:inherit;font:100%;} #ygrp-mlmsg select, input, textarea {font:99% arial, helvetica, clean, sans-serif;} #ygrp-mlmsg pre, code {font:115% monospace;} #ygrp-mlmsg * {line-height:1.22em;} #ygrp-text{ font-family:Georgia; } #ygrp-text p{ margin:0 0 1em 0;} #ygrp-tpmsgs{ font-family:Arial; clear:both;} #ygrp-vitnav{ padding-top:10px;font-family:Verdana;font-size:77%;margin:0;} #ygrp-vitnav a{ padding:0 1px;} #ygrp-actbar{ clear:both;margin:25px 0;white-space:nowrap;color:#666;text-align:right;} #ygrp-actbar .left{ float:left;white-space:nowrap;} .bld{font-weight:bold;} #ygrp-grft{ font-family:Verdana;font-size:77%;padding:15px 0;} #ygrp-ft{ font-family:verdana;font-size:77%;border-top:1px solid #666; padding:5px 0; } #ygrp-mlmsg #logo{ padding-bottom:10px;} #ygrp-vital{ background-color:#e0ecee;margin-bottom:20px;padding:2px 0 8px 8px;} #ygrp-vital #vithd{ font-size:77%;font-family:Verdana;font-weight:bold;color:#333;text-transform:uppercase;} #ygrp-vital ul{ padding:0;margin:2px 0;} #ygrp-vital ul li{ list-style-type:none;clear:both;border:1px solid #e0ecee; } #ygrp-vital ul li .ct{ font-weight:bold;color:#ff7900;float:right;width:2em;text-align:right;padding-right:.5em;} #ygrp-vital ul li .cat{ font-weight:bold;} #ygrp-vital a { text-decoration:none;} #ygrp-vital a:hover{ text-decoration:underline;} #ygrp-sponsor #hd{ color:#999;font-size:77%;} #ygrp-sponsor #ov{ padding:6px 13px;background-color:#e0ecee;margin-bottom:20px;} #ygrp-sponsor #ov ul{ padding:0 0 0 8px;margin:0;} #ygrp-sponsor #ov li{ list-style-type:square;padding:6px 0;font-size:77%;} #ygrp-sponsor #ov li a{ text-decoration:none;font-size:130%;} #ygrp-sponsor #nc { background-color:#eee;margin-bottom:20px;padding:0 8px;} #ygrp-sponsor .ad{ padding:8px 0;} #ygrp-sponsor .ad #hd1{ font-family:Arial;font-weight:bold;color:#628c2a;font-size:100%;line-height:122%;} #ygrp-sponsor .ad a{ text-decoration:none;} #ygrp-sponsor .ad a:hover{ text-decoration:underline;} #ygrp-sponsor .ad p{ margin:0;} o {font-size:0;} .MsoNormal { margin:0 0 0 0;} #ygrp-text tt{ font-size:120%;} blockquote{margin:0 0 0 4px;} .replbq {margin:4;} --> |
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Re: RF Systems DX-One Pro MkII - Bi-Loop or not ?
Fraser
CORRECTION.....
--- In loopantennas@..., "Fraser" <fraser.castle@...> wrote: it.
OOOOPs, I forgot the url for Universal ! Here are some urls related to the DX-1 and a review :-) and a review here.... fraser |
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New file uploaded to loopantennas
Hello,
This email message is a notification to let you know that a file has been uploaded to the Files area of the loopantennas group. File : /dx1.pdf Uploaded by : frasercastle <fraser.castle@...> Description : RF Systems DX-One manual & specs You can access this file at the URL: To learn more about file sharing for your group, please visit: Regards, frasercastle <fraser.castle@...> |
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RF Systems DX-One Pro MkII - Bi-Loop or not ?
Fraser
Hi All,
A new question to ponder for the Group. I own an RF Systems DX-ONE Pro MKII and have tried to establish exactly what it is from the manufacturer.... they are staying silent :-( For those not familiar with the DX-One, it looks like a giant egg beater and if you believe the sales blurb it uses a high performance, very low noise overload resistant amplifier designed for the Dutch Military. Yet another mystery amplifier design !!!! I can vouch for the low noise element of the claim and it does perform very well at my rural UK location with good rejection of the house noise field. What still mystifies me is exactly what it is in terms of antenna type. It looks like the Bellini Tosi crossed loop DF antennas that I used to use on ships so I wondered if it is a crossed Bi-Loop to give omnidirectional covereage ? I suggested this to the manufacturer and received no response. It could be a compound monopole (folded up into the diamond shape) but the antenna is ground independant and requires only a safety ground for it's inbuilt ESD protection. I have gone as far as X-Raying the antenna "guts" but that did not reveal it's secret. there is a complex amplifier and several torroids. One appears to connect to the "loop arms" and another is at the output connector end of the amp. I should be grateful for any comment that this groups members may have on this antenna and it's design principle. Loop or Not Loop antenna, that is the question :-) I will post a picture of the DX-One in the photos area of this group for those who do not know of it. Fraser |
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Re: WL1030 amplifier diagram
At 14:03 07/05/12, Digest Number 813 wrote:
Posted by: "Steve Ratzlaff" steveratz@... steveratzClick! (and save web page) The higher-resolution image obtained then zooms quite well in Irfanview - it looks a bit blue-fringed, like a slightly out-of-focus scan of a ballpoint pen original, but quite readable. Regards, LenW -- Content of a follow-up post should exceed quoted content. (rfc1855) |
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Re: Wellbrook ALA1530
At 14:03 07/05/12, Digest Number 813 wrote:
Posted by: "n2chi" davidgriffin@... n2chiAllegation of involvement in a conspiracy is not what I would call "civil" - more like "civil-actionable". How fortunate for Mr Ikin that he put his allegation into a private email and not publicly to the group! (And would most of you learn to trim so that your comment is not dwarfed by your huge quote?) Regards, LenW -- If you are sending a reply to a message... be sure you summarize the original at the top of the message, or include just enough text of the original to give a context. This will make sure readers under- stand when they start to read your response.... Giving context helps everyone. But do not include the entire original! (rfc1855) |
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