당신은 주제를 찾고 있습니까 “w5gi mystery antenna – W5GI Mystery antenna multiband cz.2 vs. Bazooka Dipol HF20A Multiband HF porównanie test“? 다음 카테고리의 웹사이트 https://ppa.charoenmotorcycles.com 에서 귀하의 모든 질문에 답변해 드립니다: ppa.charoenmotorcycles.com/blog. 바로 아래에서 답을 찾을 수 있습니다. 작성자 Robert SP2ROB 이(가) 작성한 기사에는 조회수 2,279회 및 좋아요 25개 개의 좋아요가 있습니다.
w5gi mystery antenna 주제에 대한 동영상 보기
여기에서 이 주제에 대한 비디오를 시청하십시오. 주의 깊게 살펴보고 읽고 있는 내용에 대한 피드백을 제공하세요!
d여기에서 W5GI Mystery antenna multiband cz.2 vs. Bazooka Dipol HF20A Multiband HF porównanie test – w5gi mystery antenna 주제에 대한 세부정보를 참조하세요
Test porównawczy 4 anten Double Bazooka , W5GI , Dipola oraz HF20BM (HF20A) BigMama. Dlaczego BigMama bo jest wielka sprawna i opiekuńcza jak prawdziwa rodzicielka 🙂 Daje wszystko co krótkofalowcowi potrzeba.
Na poważnie to na tapetę trafiła w końcu W5GI taki sobie mały klon , który nieźle namieszał.
Obejrzyjcie cały film przewijanie i fragmentacja jest bez sensu nie da się zrozumieć i wyciągnąć wniosków .
73 i dobrej zabawy.
Podsumowanie subiektywne w kolejności najsilniejsza najsłabsza pasmo 80m lokalnie Polska.
1.Bazooka (Double Bazooka)
2.W5GI
3.Dipol
4.HF20BM (HF20A)
https://t.me/joinchat/JRksRRVtER4mfwDrJihIjQ
w5gi mystery antenna 주제에 대한 자세한 내용은 여기를 참조하세요.
W5GI Mystery Antenna – IW5EDI Simone – Ham-Radio
The W5GI Multi-band Mystery Antenna is a fundamentally a collinear antenna comprising three half waves in-phase on 20 meters with a half-wave 20 meter line …
Source: www.iw5edi.com
Date Published: 4/11/2022
View: 9865
De-mystifying the W5GI Mystery Antenna – owenduffy.net
W5GI acknowledges an article by W2OZH as inspiration for the W5GI Mystery Antenna, and describes it The W5GI Multi-band Mystery Antenna is a fundamentally a …
Source: owenduffy.net
Date Published: 12/5/2022
View: 6441
W5GI Mystery Antenna – Resource Detail – The DXZone.com
W5GI Mystery Antenna is a multi-band wire antenna that performs exceptionally well even though it confounds antenna modeling software. This antenna covers …
Source: www.dxzone.com
Date Published: 5/26/2021
View: 8186
HF W5GI Mystery Multi Band Antenna
The W5GI Multi-band Mystery Antenna is a fundamentally a collinear antenna comprising three half waves in-phase on 20 meters with a half-wave 20 meter line …
Source: www.wireantennas.co.uk
Date Published: 1/28/2022
View: 9876
W5GI Mystery Antenna – K4TR Antenna Mfg & Wireman
Description: Design by John W5GI. This antenna is a collinear array and resembles a G5RV with lots of gain on 20m. Works on the low bands with a …
Source: www.eham.net
Date Published: 11/19/2021
View: 6975
W5GI “Mystery Antenna” – HB9ID
W5GI’s “Mystery Antenna” gets a lot of attention. Possibly because of its daft name. It looks like a G5RV, but W5GI (now SK).
Source: www.hb9id.ch
Date Published: 12/21/2021
View: 774
W5GI-Multiband-Antenna – Ham-Radio – Pinterest
A multi-band wire antenna that performs exceptionally well even though it confounds antenna modeling software Article by W5GI ( SK ) The design of the Mystery …
Source: www.pinterest.com
Date Published: 5/3/2021
View: 902
884D-W5GI Multi-Band Antenna (Fully Assembled)
The now famous “Mystery” antenna introduced in CQ Amateur Radio in July 2003. Created by John Basilotto, W5GI. It is about 100 feet long, works 80 through 6 …
Source: thewireman.com
Date Published: 6/21/2022
View: 652
주제와 관련된 이미지 w5gi mystery antenna
주제와 관련된 더 많은 사진을 참조하십시오 W5GI Mystery antenna multiband cz.2 vs. Bazooka Dipol HF20A Multiband HF porównanie test. 댓글에서 더 많은 관련 이미지를 보거나 필요한 경우 더 많은 관련 기사를 볼 수 있습니다.
주제에 대한 기사 평가 w5gi mystery antenna
- Author: Robert SP2ROB
- Views: 조회수 2,279회
- Likes: 좋아요 25개
- Date Published: 2019. 11. 10.
- Video Url link: https://www.youtube.com/watch?v=vVdr32-eO6k
W5GI Mystery Antenna
A multi-band wire antenna that performs exceptionally well even though it confounds antenna modeling software
Article by W5GI ( SK )
The design of the Mystery antenna was inspired by an article written by James E. Taylor, W2OZH, in which he described a low profile collinear coaxial array. This antenna covers 80 to 6 meters with low feed point impedance and will work with most radios, with or without an antenna tuner. It is approximately 100 feet long, can handle the legal limit, and is easy and inexpensive to build. It’s similar to a G5RV but a much better performer especially on 20 meters.
The W5GI Mystery antenna, erected at various heights and configurations, is currently being used by thousands of amateurs throughout the world. Feedback from users indicates that the antenna has met or exceeded all performance criteria. The “mystery” part of the antenna comes from the fact that it is difficult, if not impossible, to model and explain why the antenna works as well as it does. The antenna is especially well suited to hams who are unable to erect towers and rotating arrays. All that’s needed is two vertical supports (trees work well) about 130 feet apart to permit installation of wire antennas at about 25 feet above ground.
The W5GI Multi-band Mystery Antenna is a fundamentally a collinear antenna comprising three half waves in-phase on 20 meters with a half-wave 20 meter line transformer. It may sound and look like a G5RV but it is a substantially different antenna on 20 meters. Louis Varney’s antenna, although three half waves long, was an out-of-phase aerial. Mr. Varney had two specific reasons for selecting a 3 half waves on 20… he wanted a four-lobe radiation pattern, at least unity gain and a low feed point impedance. The Mystery antenna, on the other hand, presents a six-lobe pattern on 20 meters, gain broadside to the antenna, and also low feed point impedance to simplify matching the antenna to the rig. Additionally, the Mystery antenna is designed to work at least as well, on the other HF bands as a G5RV. In short, the Mystery antenna is a sky wire that incorporates the advantages of a 3 element collinear and the G5RV antenna.
In its standard configuration, a collinear antenna uses phase reversing stubs added at the ends of a center fed dipole. These stubs put the instantaneous RF current in the end elements in phase with that in the center element. You can make these phase reversing stubs from open wire line or coaxial cable. Normally, a shorted quarter-wave stub is used, but an open-ended half wave stub would also work. The problem is that the dangling stubs are unwieldy and or unsightly.
An article written by James E. Taylor, COCOA- A Collinear Coaxial Array, published in 73 Amateur Radio, August 1989, describes a low profile collinear coaxial array.
According to Taylor, when you apply a RF voltage to the center conductor at the open end, the stub causes a voltage phase lag of 180 degrees at the adjacent coax shield. This happens because the RF is delayed by one quarter-cycle as it passes from left to right, inside the coax to the shorted (opposite) end. There’s another quarter-cycle delay as the wave passes back from right to left inside the coax and emerges on the shield at the open end. Add up the delays and you get a total time delay of one-half cycle, or 180 degrees. In essence, the coax section serves two purposes: it provides the necessary delay and provides part of the radiating element in a collinear array.
The first prototypes of the Mystery antenna used the Taylor formulas, which which called for cutting the wires to a quarter wave length using the formula 234/f(Mhz) and the coax, using the same formula, but applying an appropriate velocity factor. The first version of my antenna worked well on 20 meters but failed as a multi-band antenna.
The second antenna was built with constructed with the coax cut to the same length as the wire. This was done with the belief that perhaps the coax didn’t behave like coax and therefore the velocity factor wasn’t applicable. Surprisingly, the new antenna performed exceptionally well on 20 meters, had low SWR and performed just as well on the other HF bands and 6 meters as my G5RV reference antenna.
Step-by-Step Construction
The W5GI Multi-band Mystery Antenna looks like a plain dipole (see figure1 and photo A below) and is very simple to build.
Builders of the Mystery antenna will need the following materials:
3 wish bone insulators
About 70 feet of wire (14 gauge household electrical wire works well,)
Sufficient twin lead or open wire to make a half wave section on 20 meters. Window-type 18 gauge 300 ohm ribbon works best. The Wireman is an excellent source for antenna wire and 300 ohm line.
About 70 feet of wire (14 gauge household electrical wire works well,) Sufficient twin lead or open wire to make a half wave section on 20 meters. Window-type 18 gauge 300 ohm ribbon works best. The Wireman is an excellent source for antenna wire and 300 ohm line. 34 feet of RG8X mini-coax
An electrical connector, available from most electrical parts stores, to connect the twin lead and coax
Shrink tubing to cover the exposed coax joints
The antenna can be built in less than an hour when you have the above materials. When you’re ready to proceed, perform the following steps:
Cut the electrical wire into four equal lengths of 17 feet. Cut the two lengths of coax to 16’6 each. Cut a 20 meter half-wave section of twin lead. This piece needs to be adjusted by its velocity factor. If 300 ohm window type line is used with a VF of .91, the total length will be 30 ft. Alternatively, 450 ohm, solid 300 ohm or homemade open-wire line can be used provided the electrical length is on-half wave on 20 meters. Actual length will vary, typically between 27 and 35 ft., depending on type and velocity factor. Trim two inches of braid from one end of both lengths of coax (Item A). Trim one inch of braid and center insulator from the opposite end of both coax sections (Item B). Build a 20-meter dipole without end insulators. Note: The next two steps 7 and 8 of the construction process involve connecting only the “inner” end section of the coax section to one end of the dipole; the shield is not connected to anything here. At the other end of the coax section both the coax shield and second wire section are connected to the coax center conductor. Connect one end of the dipole to the center conductor of the coax (Item A) and cover with shrink tubing as shown in photo B below. Connect the opposite end of the coax (Item B) to braid AND quarter wave wire section, cover with shrink tubing, and connect to end insulator as shown in Photo C below. Install the twin lead through the holes of the center insulator (you may have to enlarge the holes) and solder to antenna wire as shown in photo D below. Connect the opposite side of the twin lead to the coax as shown in photo E below. Almost any type of connection will work provided the connection is stable and sealed properly. Install the antenna with the center conductor at least 25 feet high. Mine is installed in a horizontal plane; however, others have installed the W5GI antenna as an inverted-vee and are getting excellent results.
On-the-Air Performance
On 20 meters, you should expect 3-6 dB gain over a dipole and a 6-lobe radiation pattern with an elongated figure 8 pattern perpendicular to the plane of the antenna. This is typical of a 3 element collinear array. For a simple explanation of collinear arrays read “Troubleshooting Antennas and Feed lines” by Ralph Tyrrell, W1TF. On all other bands the antenna performs like a G5RV, which is really a random length dipole on all but 20 meters. M. Walter Maxwell, in “Reflections II, Transmission Lines and Antennas”, aptly describes this phenomenon. Several users report it is possible to use the antenna on 160 meters but you will need to connect the twin lead together at the point where it connects to the coax. On 160, the antenna performs like a Marconi. Those who have used the antenna on 160 say the W5GI Mystery antenna is a quieter receiving aerial compared to other 160-meter antennas.
As for the theory of operation, it remains a mystery. At least three experts tried computer modeling the antenna. All three rendered completely different findings.
You will enjoy building a W5GI Multi-band Mystery Antenna! Many hams has done so and find it to have been a fun project and an excellent performer.
Notes:
(1) Information on this page has been taken from an article published in the July, 2003 issue of CQ magazine. You can download a copy of the article in Adobe Acrobat format by clicking HERE.
(2) W5GI will build an antenna for a nominal fee. Discount prices start at $65.00, plus shipping, for the W5Gi multi-bander. Mono band antennas cost more because a 4:1 balun is used.
(3) For additional information, or to order an antenna, please call or send an mail.
(4) Dimensions for the mono-band antenna:
AND Inside wire Coax Outside wire Overall length 10.1 23′ 10″ 23′ 4″ 23′ 6″ 141 ft 4 inches 14.18 17′ 2″ 16′ 8″ 16′ 10″ 101 ft 4 inches 18.13 13′ 7″ 13′ 1″ 13′ 3″ 79 ft 10 inches 21.25 11′ 9″ 11′ 3″ 11′ 5″ 68 ft 10 inches 24.9 10′ 1″ 9′ 7″ 9′ 9″ 58 ft 10 inches 28.5 8′ 11″ 8′ 5″ 8′ 7″ 51 ft 10 inches 50.125 7′ 10 “ 7′ 4″ 7′ 6″ 45 ft 4 inches The above dimensions are for a dipole hung in the horizontal plane. They were calculated by using the formula 234/freq (MHz) plus additional length for attaching to connectors/insulators.
If the antenna is to be installed an Inverted V, increase all lengths by 5%.
Any of the above antennas can easily be used as multi band antennas by eliminating the 4:1 balun and using open wire/twin lead directly to an antenna tuner
(4) Dimensions for the multi-band antenna:
Inside wire Coax Outside wire Overall length 17′ 2″ 16′ 8″ 16′ 10″ 101 ft 4″
This antenna uses a twin lead matching stub instead of a 4:1 balun.
Use only 300 ribbon line for the matching stub. Start with 34 ft 7″, trim as necessary to obtain lowest SWR.
Mono-banders with either a voltage or current (preferred) 4:1 balun.
This antenna exhibit significant gain only on 20 meters. On all other bands the antenna performs like a G5RV.
FAQ
Can RG-58 [or any other coax] be substituted for RG-8X (mini)?
Theoretically it should work, at least electrically. The main concern is the strength of the smaller wire. A portable Mystery Antenna using RG-174 is in the planning stage. If anyone has tried using different cables, please pass along your thoughts and observations for posting on this website.
[Note: disregard velocity factor (VF) of coax-it is not applicable in my design]Can I use twin lead or open wire line directly to an antenna tuner in lieu of coax and a twin lead stub?
Absolutely. The twin lead stub is only necessary to give the antenna its multi-band characteristics.
How can I determine the twin lead Velocity Factor?
The best way to determine velocity factor is to ask the distributor or manufacturer. It is very important that the correct VF be used in calculating the length of the twin lead. 300 ohm ribbon is a good choice. There are numerous types available. The VF range from 80 to 90 percent-for 300 ohm line, which means the half wave line could be anywhere from 26.4Ft to 29.7FT. 450 ohm ribbon line typically has a VF of 95%, which means the length should be 31.35 FT. The ARRL Antenna book list VF for different lines.
[Note: Use 33 feet as the 20 m half wavelength for the above calculations.]Should I use a balun?
A balun is unnecessary and will only degrade performance. A line isolator between the end of the twin lead and the coax is recommended. It helps minimize feed line radiation and stray RF, which can cause problems in the shack.
[Note: The original article recommends the use of a 4:1 balun for a mono-band version of the Mystery Antenna; however, a balun is no longer recommended. Instead, try a quarter wave 75 Ohm matching transformer. RG59 (Beldon 8241) is a good choice. A section of 75 ohm cable cut for 20 meters 10.89 feet can be used with the the multiband antenna. It will lower the SWR on 20 m to close to 1:1 and is transparent on the others bands.]I get higher SWR readings than appeared in your article, am I doing something wrong?
Probably not. SWR is a function of several variables to include wire and cable type, height above ground, etc. The best measure to ensure the antenna is constructed correctly is the 20m SWR. It should be under 2:1 across the entire 20 m band, and if you use a 75- OHM match transformer (see above) closer to 1:1.
Can I install the Mystery Antenna as an Inverted V?
Absolutely. There are thousands of Mystery Antennas in use in many different configurations. Feedback from builders indicates that the antenna is very forgiving and will work under almost any condition to include indoors and with the ends bend.
Where can I buy a Mystery Antenna?
The W5GI Mystery antenna is available as a kit from the Wireman or, if you prefer, direct from W5GI ready to install for $100 shipped within the U.S. W5GI can also build mono-band antennas for any band 40 to meters. Call or email for a cost estimate.
PS be informed that article, text and pictures are Copy Right by W5GI now SK
De-mystifying the W5GI Mystery Antenna
De-mystifying the W5GI Mystery Antenna
The W5GI Mystery Antenna is described by its designer as A multi-band wire antenna that performs exceptionally well even though it confounds antenna modeling software (Basilotto 2004).
Notwithstanding that, this article is a quantitative analysis of the W5GI Mystery Antenna in an inverted V configuration using an NEC model of a typical installation.
W5GI’s Mystery Antenna is available for direct purchase, his website (Basilotto 2004) contains the offer W5GI will build an antenna for a nominal fee. Discount prices start at $65.00, plus shipping, for the W5Gi multi-bander. Mono band antennas cost more because a 4:1 balun is used.
Overview
W5GI acknowledges an article by W2OZH as inspiration for the W5GI Mystery Antenna, and describes it The W5GI Multi-band Mystery Antenna is a fundamentally a collinear antenna comprising three half waves in-phase on 20 meters with a half-wave 20 meter line transformer . He goes on to claim that the antenna covers 80 to 6 meters with low feed point impedance and will work with most radios, with or without an antenna tuner .
The antenna is a centre fed dipole of length 15.1m a side, with the middle third of each leg comprising a section of RG8X coax connected as a s/c stub that is electrically inserted at one third of the length from the centre. It is fed by a matching section of 300 ohm feed line that is an electrical half wave at 14.2MHz, then an arbitrary length of 50 ohm coax to the ATU / transceiver. The model used for this article uses sufficient RG213 coax to make a total of 25m of feed line to model feedline losses in a realistic installation.
The stub and the feed line elements are modelled using the techniques described at RF Transmission Line Loss Calculator. Analysis is based on calculation of the stub impedance, then the feed point impedance from an NEC model of the dipole, computed every 0.1MHz from 1MHz to 30MHz. The real performance of transmission line elements in terms of impedance transformation and loss, and a practical L-match tuner network components and loss are calculated to form a view of the overall losses in the feed arrangement from transmitter to dipole centre.
Table 1 sets out the design parameters that are common to all of the configurations modelled in this article.
Table 1: Common design parameters Item Value Design frequency 14.2MHz Height of centre 10.0m Height of ends 10.0m Length of half dipole 15.1m Included angle 180° Antenna conductor 2mm diameter copper Ground “real” ground (σ=0.005S, ε=13) Matching section line type 300 ohm open wire (1mm/8mm) Length of “matching” section 9.64m Length of coax feed line 15.4m
Table 2 sets out assumptions underlying the models.
Table 2 Assumptions Antenna is erected over “real” ground (σ=0.005S, ε=13). Ideal balun is used, and that common mode feedline current is insignificant. L-match tuner used to transform load to 50+j0 Ω to suit a transmitter. Total transmission line from antenna centre to transmitter is 25m.
The results given here, and the associated discussion are of the model as described. Different models, and in particular, real implementations will be different to some extent.
Note that this model does not pretend to model exactly W5GI’s implementation, his article does not detail the height of the dipole. The length of coax used or required is not quite clear at one point in the article, he states he used 34′ of RG8X coax, though if the antenna is designed to have low VSWR(50), the length of coax should not be critical. Though he gives a table of VSWR and impedances, the impedances are highly dependent on the length of coax feed line and therefore of limited value if other lengths or types of coax are used. The model is also senstive to variables like ground parameters, the built environment, vegetation etc. Rather, the model used here gives an expectation of what might be expected in a typical application, and serves as a framework to review some of the performance claims.
Analysis
Antenna system input impedance / VSWR(50)
Fig 1: Impedance at input to 15.4m of RG213 feed line
Figure 1 is a plot of the R and X values at input to 15.4m of RG213 feed line against frequency. The plot is cropped to show only the low R and X ranges, values off the plot will have unacceptable losses with practical lengths of coax line. The impedance seen by an ATU or transceiver is of course dependent on the length of coax used.
Fig 2: VSWR at input to 15.4m of RG213 feed line
Figure 2 is a plot of the VSWR on the coax at the base of the matching section. The plot is cropped to show VSWR<10, values off the plot will have unacceptable losses with practical lengths of coax line. Longer coax sections or lossier coax will reduce the VSWR. This VSWR results from the model do not support the designer's claim that the "antenna covers 80 to 6 meters with low feed point impedance and will work with most radios, with or without an antenna tuner" whatever "work" actually means. In this case, VSWR is below 2:1 in only two regions, but none of them are inside an amateur band. It may be possible with a little tuning to get less than 2:1 in part of the 15m and 12m bands. The input impedances provided by the model suggest that not only will this antenna require an ATU on ALL HF bands, but it is probably beyond the limited range of many internal ATUs and a wider range external ATU will be necessary to comply with the load specification of most modern transceivers. Quarter wave transformer In a side note to the 20m impedance figures in his web article, W5GI says "A electrical quarter wavelength of 75 ohm cable will reduce SWR to 1:1 and will not have any affect on other bands". It is not clear where this line section would be deployed, but in the absence of specific instructions, I assume that it goes in front of the antenna system as described, ie between ATU and 50 ohm coax section. Three half waves on 20m W5GI claims that the antenna is three half waves in-phase on 20m. Fig 3: Current magnitude and phase at 14.2MHz The currents calculated in the NEC model do not support the claim that the three half waves are in phase on 20m, see Figure 3. Fig 4: Azimuth radiation pattern at 30° elevation at 14.2MHz Figure 4 shows the model azimuth radiation pattern at 30° elevation at 14.2MHz with six lobes, characteristic of three half waves out of phase. The pattern does not show the dominant broadside lobe in the +Y/-Y directions that would be expected from three half waves in phase. The antenna delivers maximum gain at 30° elevation, at which the four broader minor lobes are only 1.5dB less gain than the two narrow broadside lobes. The designer claims a 3-6dB gain over a dipole and a six-lobe radiation pattern with an elongated figure-8 pattern perpendicular to the plane of the antenna , though he gives no evidence to support this. Two key points emerge: This NEC model indicates a 6 lobe pattern on 20m at the elevation where maximum gain occurs, and is consistent with W5GI's claimed pattern; W5GI's claimed 6 lobe pattern questions whether the antenna is actually three half waves in phase on 20m. Antenna system loss Fig 5: 15.4m RG213 - tuner Figure 5 shows antenna system loss from the model. Loss in the copper conductor forming the dipole, and losses within the coaxial stubs are included in the "Dipole" category. The "Line" category includes loss in the 300 ohm matching section, and the 15.4m RG213 to the ATU. "Tuner" losses are for a practical L match. The L match used for tuner loss is in general, the most efficient way to transform the load impedance. Using the loss of a practical L-match tends to underestimate the loss in any other tuner configuration. Note the large peak in "Dipole" loss at 12.3MHz. This coincides with the quarter wave resonance of the stubs, at which point they offer a very high resistive component that converts a large part of the RF power to heat. Not a big issue since there is not amateur band within the main peak, but it shows that transmission line elements aren't lossless, and they demand careful design consideration. The stubs do not provide very much inductive loading on the lowest frequencies, do not provide the phase reversal claimed and in-phase pattern, eat power, offer more wind resistance, and are probably weaker than practical HDC antenna wire, the antenna is probably better without them. Most of the "Line" loss is due to loss in the RG213 feed line. Use of lossier grades would exacerbate the problem. Eliminating coax operating at high VSWR will improve efficiency of the antenna system. The loss curve has some narrow sweet spots that coincide roughly with many of the lower HF bands, the challenge with a real antenna is whether those sweet spots are in the relevant bands, or adjustment so that they are so. Model of classic cophased three half waves collinear A model of a classic cophased three half waves collinear using wire phasing sections was constructed at 15MHz a height of 10m over average ground. Fig 6: Figure 6 shows the structure and current distribution. The feed point impedance at resonance is 265+j0Ω. The high feedpoint R is due to high radiation resistance, due in turn to the high current moment of the three half waves in phase. W5GI reports measured impedance for his antenna and VSWR, though he does not give the height of the antenna, or length of coaxial feed line to the measurement point. Nevertheless, the impedance seen at the source end of his half wave of 300 ohm line should be in the range of 250Ω to 350Ω, which would cause VSWR of 5 to 7 at the load end of the coax, a little lower at the source end. W5GI's measured VSWR=1.5 at 14.2 (where he claims three half waves in phase) is inconsistent with the higher impedance expected of in-phase operation. Note that W5GI does not use a balun on his multiband Mystery Antenna, so common mode feed line current will somewhat modify feed point impedances. Fig 7: Figure 7 shows the radiation patter at maximum gain for the classic model. This is clearly a two lobed broadside pattern, and is the pattern expected of three half waves in phase, the minor lobes are more than 20dB down on the two major lobes. Possible improvements The coax stub sections: do not achieve the phase reversal claimed; are lossy; are subject to ingress of water; have higher wind resistance; and are lower in strength than practical antenna wire (eg 2mm HDC). The stubs could be replaced with plain conductors without degrading the antenna overall. What you then have is essentially, a G5RV. For further information, see: Eham reviews Fig 8: Figure 8 shows a summary of 31 eHam reviews of the W5GI Mystery Antenna at 14/07/2009 (Eham). The average score is 4.4, so most users seem very happy with it, even though it works quite differently to the designer's representations. That might speak more of modern ham's quiet acceptance of the designer's claims and the commercialisation of antennas than objective assessment, and possibly of the reliability of eHam reviews. Update 25/10/2013: The eHam reviews link has only 14 reviews at this date whereas there were 31 entries at 14/07/2009 summarised above. at this time of the 14 reviews, 13 are 5/5 which is way better than 2009. It does look like there is something dodgy with eHam reviews disappearing resulting in a better overall review, confirming suspicions of the reliability of eHam reviews! Fig 9: Figure 9 is a screen shot of the reviews in early 2009. Patents (Dube nd) claims It is the ONLY "W5GI Mystery Antenna" that is registered with the United States Patent and Trademark Office Registration Number 3,805,488 . A US patent search on 19/09/11 returns an entry for patent 3,805,488 issued in 1974 for a "capper chuck device", nothing to do with the W5GI Mystery Antenna... more mystery! Searches for ttl/"Mystery Antenna", in/Basilotto, and an/Basilotto returned no hits. A search for trade mark registration does turn up registration of W5GI MYSTERY ANTENNA to Dube in 2009. Conclusions Inconsistencies between the W5GI Mystery Antenna at 14.2MHz and a classic Three Half Waves Cophased Collinear include: feed point impedance implied by the reported VSWR measurement; and reported 6 lobe radiation pattern. The use of the coaxial sections provides very little loading, and the expense of: loss; added expense; increased weight; higher wind resistance; and lower strength. Analyses that ignore or incorrectly size stub loss or transmission line loss are incomplete and unreliable. A system view provides a complete picture of performance . Model VSWR is not less than 2 in any amateur bands which: drives coax loss; and needs ATU for development of rated power from modern transceivers. The model loss curve has some narrow sweet spots that coincide roughly with many of the lower HF bands, the challenge with a real antenna is whether those sweet spots are in the relevant bands, or adjustment so that they are so. Links / References How was it done? The analysis is based on an NEC model of the radiator, using 4NEC2. A PERL script was written to calculate the stub impedance at frequencies from 1MHz to 30MHz in 0.1MHz steps, and to construct and run NEC models. Another PERL script parsed the NEC output and summarised the data as input to a spreadsheet for presentation development. Transmission line parameters come from the Transmission Line Loss Calculator and Two Wire Transmission Line Loss Calculator. (Note that none of the results depend on approximations based on VSWR, in fact VSWR is calculated during the analysis for presentation, but not used as an intermediate value... ie nothing is calculated from VSWR.) Changes Version Date Description 1.01 30/03/09 Initial Use at your own risk, not warranted for any purpose. Do not depend on any results without independent verification. © Copyright: Owen Duffy 1995, 2021. All rights reserved. Disclaimer.
HF W5GI Mystery Multi Band Antenna
The design of the Mystery antenna was inspired by an article written by James E. Taylor, W2OZH, in which he described a low profile collinear coaxial array. This antenna covers 80 to 6 meters with low feed point impedance and will work with most radios, with or without an antenna tuner. .Any length of 50-Ohm coax to shack. SO 239.
It is approximately 100 feet long, can handle the legal limit, and is easy and erect. It’s similar to a G5RV but a much better performer especially on 20 meters.
The W5GI Mystery antenna, erected at various heights and configurations, is currently being used by thousands of amateurs throughout the world. The “mystery” part of the antenna comes from the fact that it is difficult, if not impossible, to model and explain why the antenna works as well as it does. The antenna is especially well suited to hams who are unable to erect towers and rotating arrays. All that’s needed is two vertical supports (trees work well) about 130 feet apart to permit installation of wire antennas at about 25 feet above ground.
The W5GI Multi-band Mystery Antenna is a fundamentally a collinear antenna comprising three half waves in-phase on 20 meters with a half-wave 20 meter line transformer. It may sound and look like a G5RV but it is a substantially different antenna on 20 meters. The Mystery antenna presents a six-lobe pattern on 20 meters, gain broadside to the antenna, and also low feed point impedance to simplify matching the antenna to the rig. Additionally, the Mystery antenna is designed to work at least as well, on the other HF bands as a G5RV. In short, the Mystery antenna is a sky wire that incorporates the advantages of a 3 element collinear.An article written by James E. Taylor, COCOA- A Collinear Coaxial Array, published in 73 Amateur Radio, August 1989, describes a low profile collinear coaxial array.
According to Taylor, when you apply a RF voltage to the center conductor at the open end, the stub causes a voltage phase lag of 180 degrees at the adjacent coax shield. This happens because the RF is delayed by one quarter-cycle as it passes from left to right, inside the coax to the shorted (opposite) end. There’s another quarter-cycle delay as the wave passes back from right to left inside the coax and emerges on the shield at the open end. Add up the delays and you get a total time delay of one-half cycle, or 180 degrees. In essence, the coax section serves two purposes: it provides the necessary delay and provides part of the radiating element in a collinear array.
eHam.net
KI5IO Rating: 2022-06-28 Great Antenna !! UPDATED Review Time Owned: more than 12 months. This is just an update on the W5GI Mystery Antenna that I’ve now had in use since 2010. It has worn very well in our hot Texas sun and I’ve not had to do any repairs or maintenance to the antenna.
I’ve had a number of conversations with K4TR and his support in answering my questions have always been just excellent.
The cost for the antenna is also well within a tight budget and Joe Dube (K4TR) has a number of other antenna options to choose from to suit an OM’s needs.
As I’ve noted the W5GI Mystery Antenna is working very well for me in a limited suburban lot and at weird angles due to same.
I can heartily recommend this antenna and the support from Joe Dube (K4TR) is simply excellent.
73 – ki5io
Nolan K
Plano, TX
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I’ve had the W5GI Mystery Antenna (from K4TR) in use for almost two years and am very pleased with its performance.
I have a limited suburban lot with ‘no’ trees so have put up fiberglass mast sections to create the supports at each end and middle. Middle support is clamped to my chimney giving me all of about 30′ over grade.
Antenna tunes without any problem (I use an LDG AT-200Pro with my FT2000D) and I have received many comments about good copy.
It was worn well in the Texas heat for two years ‘in the sun’.
It is well built and works well. A very good investment … AND … support from K4TR is superb.
Don’t hesitate to look into this antenna and install it at your QTH.
73,
Nolan Kienitz
KI5IO
Plano, TX
W2AAT Rating: 2018-10-27 he W5GI really works Time Owned: more than 12 months. Years ago I was looking for an antenna to install in the woods behind my house. I should note that I live in a HOA, so the antenna had to be somewhat stealth. I came across Joe’s web page and gave him a call. After about a half hour discussion, Joe suggested the W5GI. BOY, was he on the mark. I had used dipoles and a G5RV. The W5GI out performed these as well as other antennas.
I used the antenna for several years, then a tropical storm took the antenna down. Being an old timer, I decided to build my own.. Just like Joe’s… Been using the W5GI ever since.
Important note: There those out there that say the antenna is bad because it can’t be modeled. It may not model well, but it sure doesn’t have a problem working the world. Also,with the nodes, the antenna is almost omni directional.I communicate in all directions…
K3DFL Rating: 2018-08-13 Amazing antenna Time Owned: more than 12 months. I was able to earn my WAS (digital) and DXCC (digital) with this antenna at about 25′ and an old Kenwood TS-140S running 50w (with Kenwood AT-250 Tuner). Indeed, the ladder line is draped over my wooden fence as I an unable to get it up higher.
I was even able to get about 30 states on 160MHz with this antenna.
Overall an amazing antenna.
I am now running an IC-7300 and this antenna continues work extremely well.
K4DFH Rating: 2018-05-30 UNBeatable Antenna! Time Owned: 0 to 3 months. I must say that till now I have never actually bought an antenna. K4TR changed that. I had been off the air for several years, and when I went to go on air again, I had no junk box to build out of. I have never used anything but an 80m dipole with a tuner, and was really pretty happy with the set up. Getting back on the air, I decided to do a look-about to see what others were using, and their results. The W5GI just kept floating to the top of the list. I looked it up and started costing it out. Between parts and materials, with shipping, it was not a cheap proposition. Then I came across W4KTR’s website with the W5GI. It turned out I could buy the antenna already assembled for not much more than the total of my materials list (with shipping). Certainly not enough more to justify ordering, waiting for parts and materials, and then building it.
My K4TR, 80/6 W5GI is now hung flat-top at about 17′. I don’t get over 2.5:1 SWR at any portion of any band I have tried it on, but I have an MFJ 939, so why not use it… SWR is negligible wherever I tune. With the tuner, I can even work 160 with it. Performance is very good, even with the spring, 2018 propagation. I have made numerous DX contacts on 40 with it, and routinely get S7 to S9 reports from Europe to Russia. Not bad for 100 Watts and a wire.
I am impressed with K4TR’s materials and construction. Materials appear to be first rate, and all joints are cleanly and solidly soldered. This is a VERY well made antenna. I expect, barring accidents of nature, this will be my last antenna.
W8BBM Rating: 2017-10-24 Simply Outstanding Time Owned: more than 12 months. I was looking for an antenna to put up at my cottage station and I build this antenna 11 years ago on a whim from an article in the old CQ magazine. To my pleasant surprise this antenna performed incredibly well. I worked DX regularly on ALL BANDS including 160 meters. The antenna has been durable and has survived 11 wind blown summers and winters on the shores of Lake Huron without a single issue. Unfortunately I recently had to take it down as Ash Bore took out all of the Ash trees I had in the back yard leaving me short of areas to tie it off. I am now going to figure out how to put it exact same antenna back up. It looks no worse for the wear.
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Earlier 5-star review posted by W8BBM on 2012-12-17
I found the original article from CQ some 5 years ago on this antenna and decided to build it as the primary antenna to my cottage station and it did not fail to impress. I have built and used many antennas in the past but in short, this antenna perfoms exceptionally well and had decent 2:1 or lower SWR on all bands except 17 and 30 but was still very usable there with a tuner. I have worked tons of DX with it and even some nice 160 meter DX on phone with the leads shorted as suggested. I am located on Lake Huron with very high winds being a regular occurance and the antenna has always stayed together just fine. Don’t get me wrong, I am not saying it would rival a beam but for $50 dollars in material and ability to work pretty much anything I can hear using only 100 watts, I struggle to find anything that could compete for the money. Build it and enjoy!!!
KD6SX Rating: 2017-05-03 Excellent wire antenna Time Owned: more than 12 months. I have had this antenna for over a year now and am very happy with it. I have it installed as an inverted vee with the top at 40 feet and the ends at about 15 feet.
The SWR is 3:1 or less on all bands except on 30 and 17 meters where it is considerably higher. But my rig’s internal tuner tunes it just fine on all bands. I was surprised and pleased to discover that it is at least a couple of S units better than my 32 foot vertical on 40 meters and at least as good as my 132 foot doublet on 80 meters. It is very good, of course, on 20 meters since it was primarily designed for that band. It does a very adequate job on the rest of the bands also.
I had to experiment a little to get the right coax length to keep my rig’s tuner happy. I ended up adding 8 feet to my initial coax length and that did the trick.
It’s nice to have one wire antenna that works well on all the bands on which I operate–and without needing to keep tuning an external antenna tuner when I change bands.
Good antenna.
73,
KD6SX
HB9EGO Rating: 2016-02-19 New world Time Owned: 0 to 3 months. I’ve had the W5GI Mystery Antenna from K4TR for almost two years somewhere in the shack waiting to being used! Last week I found the W5GI Antenna in a plastic bag and decided to make a last effort!
My QTH is surrounded by buildings and heavily wooded hills. A headache are the neighborhood and my lovely XYL! My most preferred equipment is the Drake TR7 line.
Till now I worked with OCD and end fed Antennas with various UNUNS and configurations. Contacts with the US or Asia was more than a dream.
With the W5GI I entered in a new world of Ham Radio.
For the first time I made QSO with US and Far East even with moderate propagation.
I would like to point out the good Service, Quality and quick delivery time of K4TR.
73
KC8RGV Rating: 2015-12-12 Great Antenna Time Owned: more than 12 months. I Bought The W5GI Mystery Antenna SR 160/6 And What A Awesome Antenna It Is My Lot Is 100/75 Feet And On My ROAM 45 G Tower At 50 Feet At The APEX It Fit Right In With No Problem And Looks Good To For A Wire I Am Having A Lot Of Fun On 160 With It Getting Good Reports On 80/40 Also But I Have The 80/6 Also And Get Good Reports On 80/6 On It As Well. What A Great Set Of Antennas They Are The Best Money I Have Spent For The Space That I Have. Awesome Antennas.
KT4XP Rating: 2015-07-02 Great 80 thru 6 antenna Time Owned: 0 to 3 months. I have had this up for one month.I have used this on 80,40,30,20,17,15 and 6.(band condx on 12 and 10 seemed not good) all with good results.Today I worked Market Reef on 17 meter CW,I wont say it was easy with 100W and a wire antenna,but after a few calls and two or three repeats,I got through.17 meters is not that great a match on this antenna(a decent amount of SWR)but my ic-746 pro auto-tuner had no problems on any band.20 meters is the best performer for this antenna,(phase reversing stubs come into play on 20 meters)using the optional matching stub(20m) very low SWR.This antenna replaced a Carolina Windom in the same exact location,and I believe it beats it in performance Hands Down,No line radiation,etc.If your considering one of those antennas I would recommend the W5GI,and the line isolator for 20m from K4TR Joe Dube.Great service and fast shipping.The only mods I did was to replace the silicone sealant with polyurethane sealant and tightly over wrap the wire where it is wrapped at the end insulators with super 33 electrical tape(I get nervous when I cant solder that connection).It is configured as a flat top,the height is about 40 feet.
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