After doing a bit of reading decided to give building a quadrifilar helix qfh antenna a try. This helps in noise reduction and elimination of null spots. Noaa weather satellite image reception adam zeloof. May 11, 2015 a software defined radio is a radio communications system where components that have typically been implemented in hardware e. However, there have been descriptions in the magazine of the group for earth observation geo of how to build a qfh using easily available copper pipe. It works even better if you add reflectors below the vdipole.
So i decided to build a qfh antenna to ble able to receive noaa apt signals. This antenna, which is very forgiving in tolerances, is an ideal feed for offset fed parabolic reflector. This link is listed in our web site directory since monday oct 29 2007, and till today quadrifilar helicoidal calculator has been followed for a total of 1921 times. Once relatively anonymous, this incredible tool has gained. The design of our qfh is largely based on the assembly manual written by paul hayes and on the software made by g4unu and recalled by. This paper proposes a novel method to investigate radiation pattern measurements such as half power beam width hpbw and fronttoback ratio of quadrifilar helix antenna qha using usrp2 and gnu radio. Aug 04, 2019 using software defined radio techniques, you can use these antennas to pull off weather satellite images and other space signals. Building a quadrifilar helix antenna qfh for noaa satellite. This article describes how to make a quadrifilar helix qfh antenna easily, from inexpensive materials. Description of the construction of a quadrifilar helicoidal antenna. Antenna, ve3sqb ham radio antenna design software programs. The figure1 depicts typical qfh antenna designed with larger loop and smaller loop.
A qfh antenna for the weather satellite band with images. A qfh antenna for the weather satellite band this article describes how to make a quadrifilar helix qfh antenna easily, from inexpensive materials. I used a 40mm pipe for the center rod and 16mm cable duct for the arms. Design, construction and performance analysis of helical antenna operating at 5. The antenna i went for is called a qfh quadrifilar helix and appears to be only commercially available in expensive marine or professional versions. John coppens on6jclw3haz describes how to make a quadrifilar helicoidal antenna taming the qfh antenna by bill sykes g2hcg and bob cobey. Quadrifilar helicoidal antenna javascript online calculator. The other antenna was made by antenna specialist who are still in business and may still produce the super scanner. Design, construction and performance analysis of helical. How to build a qfh quadrifilar helix antenna to download.
I have a r820t2 stick that i have bought from ebay. This antenna, which is very forgiving in tolerances, is an ideal. By using relays, a single feed line could be switched to 1 of 3 elements or to all for an omni position. Eznec proprietary software program that performs analysis of antenna systems based on the. A discounted kit comprising a passive vhf qfh antenna for uplink, an amplified uhf qfh antenna for the downlink, and a bias tee. By bob and jann koepke when we think of ground stations for satellites, large antenna arrays and dishes immediately come to mind, along with a lot of expensive electronics. Qfhquadrifilar helix antenna basics,qfh antenna calculator.
We have made many loops with different diameters and, for example, an 8 mm pipe diameter antenna shows an impedance of about 21 ohm, whereas a 15 mm antenna is about 30 ohms impedance. Pvc pipe, copper wires or thin tubing, coaxial cable and bnc connectors are used in its construction. A quadrifilar helix antenna for 7 mhz by george goodroe, kf4cpj. The quadrifilar helix antenna qha is a simple and inexpensive solution to the problem of nongeosynchronous satellite research. The grabcad library offers millions of free cad designs, cad files, and 3d models. This model is for meteorological satellites, but a calculator is provided to adapt measure to. John coppens qfh antenna online calculator thank you very much. Building a quadrifilar helix antenna for undergraduate. The two qhas are completely independent, but the 70 cm qha is built inside the 2 m qha.
Qfh antenna for receiving satellite images using rtlsdr. The resource is currently listed in in 2 categories. Measurement of radiation pattern of quadrifilar helix. Ive had one of these for months, and havent really done anything cool with it. More importantly, it changes the impedance of the antenna. I am building a qfh antenna following this tutorial.
Trees and buildings block the signal from the satellite. It is therefore logical that it should otherwise work the same as the original, but have opposite lefthand polarization. I have mounted this qfh about 25 feet off the ground. It does not generate qha dimensions for your design frequencyfor that youll want to use john coppenss. This site is for all those interested in monitoring the weather satellites it includes a ilustrated step by step guide to making your own qfh, international wxsat imaging competition, links to decoding and tracking software such as, wxtoim, wxsat, satsignal, wxrack, u. This antenna is unique in its simplicity of design and powerful performance compared with standard directional receivers. Measurement of radiation pattern of quadrifilar helix antenna. Jan 25, 2016 so in my last post i was playing with my rtlsdr with an intel edison. Resources listed under quadrifilar helix antenna category belongs to antennas main collection, and get. The main category is antenna design calculators that is about antenna design calculators. This antenna works like a charm on noaa, meteorm2 and iss. The quality is even higher using this software than other software packages. The satellites of interest are noaa 15, 18, and 19.
Although, it seems that the qfh antenna is designed to be 50 ohm. The first post discusses antennas that are useful for noaa satellite reception, and shows how to build a homemade turnstile and qfh antenna. But you can receive transmissions from many satellites using very inexpensive equipment. Pdf image data acquisition for noaa 18 and noaa 19 weather. Is sensitive in all directions only to righthand polarised em waves.
Mahesh vhatkay vu2iia has used his amsatuk funcube dongle sdr to receive weather satellite images of the indian subcontinent as well as the funcube dongle software defined radio his station comprised a qfh antenna with 7 mhz preamp homebrew, wxtoim free version and spectravue you can see the images at. Mar 08, 2014 this problem can be solved by using universal software radio peripheral usrp2 and open source software gnu radio. I took a sheet of paper and cut out a 40mm wide strip. The qfh antenna consists of two types of loops in the design. Feb 16, 2017 a qfh antenna for the weather satellite band. Using software defined radio techniques, you can use these antennas to pull off weather satellite images and other space signals. Noaa satellite signals with a pvc qfh antenna and laptop. The antenna is run through a lna lownoise amplifier and into a rtlsdr software defined radio. So youve got an sdr, and want to try something new. Qfh antennas provides circular polarization and a near hemispherical coverage. The antenna i made was a qfh quadrifilar helix antenna tuned to 7. How to build a qfh antenna for noaa weather satellite reception. No bending and soldering of copper pipe is required. Since the 2 m antenna is resonant also on 70 cm, i was worried the outer antenna might shield the inner one, or at least change.
The second row, where both the twist direction and the feedpoint have been mirrored, is a complete mirror image of the entire antenna. So my question is, which coax cable i should use to build the antenna. The tv antenna is a highly directional piece of hardware which is pointing toward green bay where most of the tv broadcasts are located. After i became a licensed amateur radio operator in august of 1995, i received a qst magazine which had an article that explained it was possible with the right antenna, the quadrifilar helix antenna qha, to receive the 7 mhz weather satellite transmissions. I think, from what i have read that this stick has a 75 ohm receiver.
Designing an openended quadrifilar helix dassault systemes. Sep 10, 2017 the antenna i made was a qfh quadrifilar helix antenna tuned to 7. For the top of the antenna you are going to have to drill 4 holes at right angles to one another. Nov 30, 2018 if you want to build an antenna to receive signals from a weather satellite, you will need a special kind of circular polarized antenna known as a quadrifilar helix antenna. Pdf image data acquisition for noaa 18 and noaa 19. Whilst the calculations using the calculator seemed to work well, instead of the intended 7. Join the grabcad community today to gain access and download. For the reception of polar orbiting satellites therefore, it is desirable to have an antenna which.
Currently an airspy mini is used with software by lucas teskes open satellite project to decode high rate information transmission emergency managers weather information network hritemwin from noaas goes16 satellite geostationary operational environmental satellites. So in my last post i was playing with my rtlsdr with an intel edison. An antenna often, but not always, center fed with two halves along the same line. Quadrifilar helicoidal calculator resource detail the.
Changing the diameter changes the resonant frequency only a little. Used in conjunction with a rtlsdr usb radio dongle and software, images of each satellites pass can be recorded. About quadrifilar helicoidal calculator the resource is currently listed in in 2 categories. Qfh antenna for receiving satellite images using rtlsdr there is an incredibly popular lowcost software defined radio, known as the rtlsdr. Mahesh vhatkay vu2iia has used his amsatuk funcube dongle sdr to receive weather satellite images of the indian subcontinent as well as the funcube dongle software defined radio his station comprised a qfh antenna with 7 mhz preamp homebrew, wxtoim free version and spectravue.
The ublox gps module lea5t has options specifically for timing which i intend to use. Uhf circularly polarized directional antenna estimated cost. Often a reference antenna and also used as an element of multielement arrays. If i will go outside and rotate the antenn i can then get an ok signal. The qhf qfh antenna is another interesting teardown. Requirements such as sturdy construction and low weight are of less importance in terrestrial antennas. This version of the 5mhz quadrifilar antenna for apt reception is an adaptation from bill sykes and bob cobeys article taming the qfh which appeared in the march 1997 rig magazine. If something goes wrong, carrying out repairs is a minor problem. Mar 25, 2015 qfh antenna for receiving satellite images using rtlsdr there is an incredibly popular lowcost software defined radio, known as the rtlsdr. This is a quadrifilar helicoidal antenna structure serving as a base for building a 7mhz noaa satellite reception antenna. Other qhas ive built the quadrifilar helical antenna qha, or qfh if you prefer has two defining properties. Used in conjunction with a rtlsdr usb radio dongle and software.
My analyzer of the time didnt go to uhf, but the radio was happy enough with the antenna. Simulation of quadrifilar helical antennas of uuki oh2gvb. On the pc, free private use software is now available called wxsat. This instructable covers everything youll need to get started in being able to receive the apt automatic picture transmission signals from the noaa satellites noaa15, 18, and 19 flying overhead and can be a foundation for listening to other. This problem can be solved by using universal software radio peripheral usrp2 and open source software gnu radio. These noaa weather satellites broadcast a apt signal with about 5 to 8 watts at 2m band, and considering how low this power is, it might suprise you that these signals arrive pretty strong at earth surface. In this case the description and design info for a helix antenna. The designed antenna figure 4 is a qfh antenna is a. An inexpensive rtlsdr software defined radio usb dongle and an omnidirectional antenna is a. Construction is cheap, and materials are easily available.
If you want to build an antenna to receive signals from a weather satellite, you will need a special kind of circular polarized antenna known as a quadrifilar helix antenna. Building a simple and inexpensive satellite ground station. I have just completed my first hand wired gps module and diy qfh backfire antenna for 1575 mhz, and thought id share my project and sources. The antenna looks a bit like a corkscrew and can be either lhcp left hand circular polarisation or rhcp right hand circular polarisation. Using values from online calculator, measure top and bottom arm distances, center support arm distances for both bottom and top. This will require you to make two templates, one for the top of the pipe and one for the bottom. In particular at the horizon, the antenna must be rhcp requirement 6. This is extra crummy bc i use the scope to roughly tune my magnetic loop antenna, not happening in this software.
Inexpensive noaa apt ground station utilizing the rtlsdr. This too is then exported to cst studio suite and simulated. There is an incredibly popular lowcost software defined radio, known as the rtlsdr. Quadrifilar helix antenna 7 mhz for noaa weather satellites. The coax jumpers made the other 2 unactive elements. If you have been put off making one of these highly effective antennas because you thought it was difficult, that you needed to be a timeserved plumber, or that the antenna wont work unless. Quadrifilar antenna tuned for picking up 7mhz signals from noaa weather satellites. The antenna can be designed without entering any design objective values or only specifying some objectives. I calculated the measurements for both qhas using john coppenss quadrifilar online calculator. Often refers to an antenna with a length equal to half an electrical wavelength.
The kit allows you to configure some of the antenna characteristics polarization, vhf connector and cable lengths. How to build a qfh antenna for noaa weather satellite. In order to receive anything of quality a satellite would need to be located in the sky exactly where my tv antenna is pointed. I chose to use 8mm pipe, and the design by bill sykes g2hcg and bob cobey g0hpo. This model is for meteorological satellites, but a calculator is provided to adapt measure to other frequencies. Please practice handwashing and social distancing, and. Files from the hritemwin stream are made available in aws s3. In this video, well go through the theory and practice behind how to build a qfh antenna. The antenna i went for is called a qfh quadrifilar helix and. The qfh or quadrifilar helixm besides being a very nice postmodern sculpture for the inexperienced, is an antenna that suits excellently to the reception of signals from satellites or from aircrafts without the need of pointing. This antenna beams into three quadrants without the use of a rotator. Ive also notice that if i move the antenna such as leaning it or pointing the top of it at the horizon the reception is better. Antenna magus suggests the shortcircuited quadrifilar helix antenna. Recently ive seen a lot of people on the rtlsdr reddit building quadrifilar helix qfh antennas to receive images from satellites using automatic picture transmission apt.
Exhibits a radiation pattern in the upper hemisphere, which matches the pattern shown in figure 2. It still has some noise in it but its a night and day difference. Tbd a less common type that are circularly polarized. The swr minimum of the 2 m qha was close enough according to my antenna analyzer, and the impedance was quite close to 50 ohms.
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