Communication with reflection from the lunar surface (EME) and reflection from meteor traces (MS). Moonlink powerful RA for communication through the moon

The moon is a natural satellite of the Earth. Its diameter is 3476 km, the average distance from the Earth is 384900 km. The angular diameter of the moon when observing the Earth is 33 minutes. The moon moves around the earth in the direction from the west to the east with an angular velocity of 12-13 ° per day, returning to the same position relative to the Earth and the Sun one lunar month, which is 29.53 average sunny day. The orbit of the moon is tilted to the plane of the Earth orbit at an angle of 5 ° 9 '. Due to the inclination of the axis of the earth relative to the plane of its orbit by 27 ° 27 '

The moon from the territory, for example, the European part of Russia is visible at angles from 11 ° to 68 °. The exact angular position of the moon relative to any point on Earth is given in astronomical yearbooks. The surface of the moon has a reflection coefficient for radio waves 0.1. The effective reflecting surface of the moon is a circle of 340 km with a diameter, which is located on the ground surface of the moon. The moon is turned to the ground with the same side. However, due to the vibration phenomenon, we see somewhat greater than half the surface of the moon. As a result of vibration, the position of the most efficiently reflective region on the surface of the moon is constantly changing, which leads to a variable in time the process of interference of reflected waves. This, in turn, leads to fluctuations (by 4-5 dB) the level of the reflected from the moon and adopted on the land of the signal. The signal level decreases to zero only in small time intervals (a few seconds) corresponding to the moments when the direction of vibration changes to the opposite.

The difference in the distance from the center of the most effective part of the reflective surface of the moon to the ground and from its peripheral part to the Earth is about 8 km, which corresponds to the spread time of the radio wave of about 100 μs. This leads to the deformation of the front reflected from the moon of waves, which limits the transmitter modulation band up to 10 kHz. A wave falling on the surface of the moon, when reflected changes the phase. Therefore, when using radio waves with circular polarization, it is necessary to take into account that after reflection, the direction of rotation of the polarized wave changes to the opposite.

The manifestation of the Doppler effect in the reflected signal is required to vibrate the moon. The sign of changes in the Doppler frequency shift when reflected from the two opposite sides of the moon is different. In the range of 2 m, the Doppler shift reaches a plus minus 2 Hz, in the range of 70 cm - plus-minus 6 Hz, in the range of 23 cm - plus-minus 18 Hz.

The time of distribution of the signal from the ground to the moon and back is 2.56 s. During this time, you can carry out manual switching antenna with reception.

The signal during lunar radio communications passes twice through the earth's atmosphere, i.e. Twice refracted in the troposphere and the ionosphere of the Earth. With low angular positions of the moon, the signal even at the normal state of the atmosphere undergoes refraction: in the troposphere - up to 1 °, in the ionosphere - to 0.5 °. With anomalous states of the atmosphere, the reduced refractive angles can be large. In this case, such a situation may occur when radiation from the Earth passes by the moon, and at a high location of the layer, the ionosphere does not leave the surface of the Earth at all.

Radio wave, passing through the atmosphere of the Earth, experiencing the effect of the Doppler effect: in the range of 2 meters, the Doppler change of frequency is 14 Hz, and 70 cm - 3 Hz. The exact value of the Doppler shift is defined both by the angular location of the station and the properties of the atmosphere. Considering that and reflected from the surface of the radio wave moon is subject to Doppler shift, and the change mark is opposite to the change mark due to the influence of the Earth's atmosphere, a situation may occur when the resulting frequency shift will be zero.

Radio wave, passing the Earth Ionosphere, under the action of its magnetic field changes the polarization plane (Faraday effect). Rotate the polarization plane depends on the path length in the ionosphere, i.e. From the angular position of the moon, and is proportional to the square of the frequency. For a 2-meter range with a low position of the moon above the horizon, the rotation of the polarization plane is 3360, that is, is nine full revolutions plus 120 °.

All your conscious life, starting from the 7th grade, I was fond of and working until now on short waves (KV). Already in the 7th grade, I first participated in competitions on short waves. Since then, I have been fascinated by this type of occupation - Competitions. At school (UK1AAN) and at the Institute (UA1KBW-UK1AAA-RZ1AWT), I worked almost in all competitions. VKE for me was not so attractive, because There was no, in my opinion, worthy competitions. And observe the noise, as my familiar OH2BR - YUKKA said, is not very interesting. I must say, in those years, the Glory of UA1MC pulled me to VHF of a field day. We traveled to the south of the Pskov region. Then, repeated connections and stations were allowed in the field day. Field day passed as a sq Contest, with a rather high pace. Working from the mountain of the judgment, we won the zone and also took the first place in the VHF field day.

Then I traveled as part of the UA1MC and UA1ASA team on Pushkin Mountains. Field days were very interesting. In 1989, I met OH2BH - Marty Lainen - a very famous person in the world of radio, traveler in various countries of the world. We were together on the expedition on the island of Small Vysotsky. He suggested that I organize an expedition to the city of Vyborg to work at 50 MHz. Vyborg does not use this frequency of the television channel. From Russia before that no one legally worked on this range. The next year we received permission and in the composition of the Russian-Finnish team successfully worked for 50 MHz.

We liked this range "PILEP" and next year, having received permission again, we left for the election already without Finns. With you, we took an antenna for 2 m (for communication with the city), and FT726R had 50 MHz and 144 MHz. The square of the CR40, from which we worked, was quite rare, so Sergey UV1AS persuaded us to make several meteor ties and ordered "Skatenes". The electronic key allowed us to work at high speed, but there was no tape recorder. We have heard only the "Borsti", but helped Sergey. I liked it, especially hear short "pings" and longer "burles". So, in general, my passion for VHF began. Next year we organized an expedition to 50 MHz under the meadow to the site of our institute. Again received permission, because In the meadow, there is also no i television channel. They made a six-element antenna for 50 MHz and 4 x 9 F9ft for 2 m. The place to work at VHF perfect - far in the forest, no interference, high mountain - 110 m above sea level. At 50 MHz were terrible "Piles". At 144 MHz days for ten, including Persians on August 12, "Squares" were painted, because Our CO48 square was rare.

The tape recorder was presented to us again Sergey UV1AS - the old coil tape recorder, conveyed to record at high speed. "Ping" and "Borsti" marked paper strips, which then fly out when reading. "Sked" was then appointed one hour, but the connection could be made faster. Meteora flew canceled, we got great pleasure. There was a moment when I stayed one for 3-4 days, and "Squares" were painted for several days in a row, barely endured. There were cases when I fell asleep during communication, and the key passed everything. For those who are not familiar with the MS communication procedure, will tell later, since now everything has changed. In 1993, Oleg Rw3tj decided to organize an expedition to the Leningrad region, I proposed to work out of the meadow in hemnides. We have never worked in competitions on meteoric relations. These competitions are organized by the Bavarian Contest Club (BCC) in December of each year during the meteor flow of hemnida (BCC Meteor Scatter Contest). This is a very strong and stable stream.

Competitions take place, as a rule, from 11 to 15 December. Such a deadline is defined by the fact that the time of MS communication from 12.5 minutes to 1 hour. The type of radiation HSCW - high-speed telegraph, was in those years, the WSJT was added in the past 3 years. We perfectly worked the contents of the ua1c call sign, took the first place with a large margin. Since then, this contest has become one of our favorite. We won many times in it and the results in it also grew. In those days, when I have not yet engaged in VHF, I still caused interest in conducting connections through the moon. Through the magazine "Radio", I followed the success of UA1ZCL and asked the glory of UA1MC, when he would communicate through the moon. But, when Glory moved to a new place in the city and put the four on the roof, a strong hurricane broke the antenna. He was not going to put a big antenna, because The gulf place was very thoughtful.

In 1995, I put a mast in the country and did an antenna of 12 elements according to my calculations. It could work "Tropo" or through meteors, but not through the moon. But I really wanted and I made an antenna of 4 x 12 elements and put it on the mast from the pipes. At first, I directed the antenna to the moon manually, and I simply made a small election by the tilt of the mast. And so I heard signals reflected by the moon. These were the strongest stations "Big Ghana": W5un, KB8RQ, K5GW, SM5FRH, F3VS, I2FAK, SM5BSZ and others. They use antenna systems consisting of 16, 32, 36, 48 antennas each. For example, the W5UN antenna system, consisting of 48 antennas for 17 elements, is located on the traverse, supported by three masts that stand on carts with electric motors. Now this design has RN6BN, but from 32 antennas. Sergey Uv1as helped me make an amplifier and in 1995 I made my first links with reflection from the moon. I was struck by enthusiasm, I would say fanatism, many "Lunnikov". Because I was a new correspondent for them, they called me home, passed through other radio amateurs, I appointed me to meet "SKED" s via the moon. Then I put "Uuzh" with the motor at the top, made element using an actuator from airplane aleons. On such a mast, I could already put the antennas more. For the calculations of the antennas, I use YO-653 program, and for checking - yagi-354 with further adjustment of the lengths of the elements in practice. For fastening items, I use a simple, but very effective way that Oleg RW3TJ suggested to me. The element dresses a tube that is removed from the radio frequency cable, and then with the tension inserted into the antenna traverse hole.

I tried a lot of different antennas: 4x12, 4x14 type SM5BSZ, 6x16 RU1AA. Antenna, on which I work now since the cottage (KP40XD), 4x15 Crossyagi - This antenna has 21.5 DBD. On the site http://www.vhfdx.net/ve7bqh.html VE7BQH Lionel brings a list of the best antennas developed by radio amateurs. The "Cross" antenna (cross) -yagi allows you to track the rapid polarization of the reflected signal from the moon. At the reception, I even select the desired polarization after 45 degrees. In principle, you can select any polarization using the SM5BSZ program using the stereo reception and two orthogonal antennas. The "Cross-Yagi" antenna consists of two antennas located on one traverse orthogonally to each other. The orthogonal antenna also includes X-jags, which are made in the form of the letter X. These antennas have an indisputable advantage over antennas with one polarization. Very famous VHF-East Sm2cew Peter wrote that he spent past many years, increasing his antenna system with horizontal polarization until Cross-Yagi did. Polarization can not only change quickly during communication, but also not to change for a very long time. There were cases, for example, in the lunar expedition to the island of Small Vysotsky R1mvz, when the reflected signals were a long time of vertical polarization and sometimes + 45O. Alexander RW1AW and Sergey RX1as did the contest only a few connections, because Arrl EME contest then, because They did not have vertical polarization, we had more than 120 connections. It was also during the ARRL in 2001, only vertical polarization signals came the whole night. More about antennas. Based on its capabilities, you can make an antenna or a group of antennas with different lengths of traverse (boom). It is necessary to know that on the same length of the boom, you can arrange a different number of items and get an antenna with a large or less amplification. I at my time went along the way of designing antennas with great strengthening, narrowband. These antennas are sensitive to weather conditions, in the rain, snow, or with the altitude of ice, the resonant frequency goes down, the KSW (the coefficient of the standing wave) deteriorates. This is due to an increase in the actual diameter of the elements. Broadband antennas have more elements at the same length, less susceptible to weather conditions, but have less amplification. A compromise can serve as the location of the elements in the form of the letter "X", the water is better from them than those located horizontally. If you compare "+" - Cross-Yagi and "X" - it should be said that "X" -Mags as a lack of more complex commutation. So, for the formation of horizontal and vertical polarizations, the adder will be required, and in the second case, the adder and phasigating chain. Unlike the KV contests, Verne of the contest, and the usual days of activity are characteristic of the fact that there are not many stations operating on CQ in the range. The number of such high-profile stations "Big Ghanov" is generally limited, not everyone can build an antenna of huge sizes for various reasons. On the sites http://www.vhfdx.de/gallery.htm and posted photos and descriptions of the largest antennas to work through the moon on different bands. There is even a category in which professional antennas (Commercial Equipment) work. So from Canada through the moon, the VE3ONT club radio station worked, which used parabola 48 meters in diameter. Build an antenna of large sizes and successfully operate in competitions I also wanted, but in the country the conditions do not allow it to do. Therefore, I decided to build an antenna on our site under the meadow (RU1A). At first we made 12x14 Crossyagi, then in 2003 it was redone it in 16x14 Crossyagi. Successfully worked in ARRL, but in December 2003 a strong hurricane threw it. It was a serious test for me and my friends who helped me. We have for this time and so many cases have accumulated at work with the antennas. But nevertheless, we found strength and time in themselves and by October 2004, put almost a new 16x14 antenna, now X-Yaga. Now about the peculiarities of links with reflection from the lunar surface - EME. Through the earth's ionosphere, frequencies start from 50 MHz. True, frequencies below 50 MHz, when there are no reflective from the layers, they also go beyond the land. One American amateur received his echo at 28 MHz. I also tried to do this at the rising of the moon on an antenna 10 m of the range of 4x5 elements, but so far there was only one unsuccessful attempt. Need a mast amplifier directly from the antenna. So, radio amateurs operate on bands 50, 144, 222, 432, 1296,2304,10000 MHz. The most difficult to carry out connections are 50 MHz, 10 GHz and above. By 50 MHz - due to large dimensions of the antennas, and 10 GHz and above - due to the complexity of the equipment. On 47 GHz Sergey Zhurtyaev RW3BP for the first time from all radio amateurs heard his echo. 1296 MHz is considered the most effective range at the necessary power and antenna value, as a rule, parabola. All bands worked and operate with telegraph, and at frequencies since 1296 MHz also use SSB, because Signal levels reach the S9 levels.

Recently, a new type of digital connection is very actively used for EME - WSJT, which has adapted and wrote for radio amateurs a well-known American physicist scientist, Nobel Prize winner and at the same time radio amateur K1JT - Joe Taylor. I happened to communicate with him, she was the second link through the moon. This view allows communication using simple antennas and low power. It has been written a lot of versions of this program http://pulsar.princeeton.edu/~joe/k1jt. . Latest version - 4.7.0, the type of radiation is called JT65. On the 50 MHz range, JT65M is used, 2 m and above, as a rule, JT65B, but by agreement you can use any kind. This program, like a number of other programs, also contains the parameters necessary for the "lunar" ties. According to the coordinates you entered or square, the program in real time shows the coordinates of the Moon: Azimuth and Element; As well as deterioration in the signal-to-noise ratio (degradation), in decibels, which is consisted of cosmos noise in the direction of the moon, plus signal weakening depending on the distance to the moon. In Periguee, the moon can be at a distance of approximately 358 thousand kilometers, in suitoee to 406 thousand kilometers. A very useful Z-Track program is written by N1Bug http://www.n1bug.net/#software, as well as the VK3UM EME Planner program http://www.qsl.net/sm2cew/download.htm. Convenient days for ties through the moon are days: 1) When the moon has a positive deviation from the equator line (declination), while it (as the sun in summer) happens above and longer over the horizon; 2) When acceptable signal degradation. Now they work when the signal degradation is not less -5, -6 dB. An important factor for ties is the days of the week, more often work on weekends. The JT65 program works in conjunction with the I2PHD and IK2CZL program "Spectran", which allows you to see, process signals, as well as their traces. This allows you to find the WSJT and CW signals on the range and configure them. These programs can be used as described, i.e. JT65 uses for decoding signals spent "Spectran" -th, and can be parallel. "Spectran" shows signals, and JT65 takes them directly from the sound card. I noticed that decoding is better. With the advent of WSJT, the number of "Lunnikov" has greatly grown, because For connections, it is enough to have one antenna and a small amplifier or the four antennas and 100-watt transceiver. Not everything, of course, for various reasons can immediately put a large antenna. But I know many radio amateurs, which even with small antennas are tiered through the moon, increasing their account of new correspondents. Here http://www.vhfdx.de/eme.html You can find the addresses of almost all sites dedicated to work at VHF and through the moon including. On the Internet you can find many sites where there is all the necessary information on EME. You can also download the desired programs. There is also a "Moon-Net" network, where there is a discussion of various issues of EME, contests, results, etc. Almost real-time you can communicate in "On4kst Chat" http://www.on4kst.info/chat144/start.php, EME Activity Logger http://www.dxworld.com/eselog.html or JT65 Terrestrial Link http: //www.chris.org/cgi-bin/jt44Talk. Dmitry Ra3AQ on its website http://vhfdx.ru/component/optioncom_frontpage/itemid 1 also illuminates the events of the "lunar" life, and even translated into Russian Language Description WSJT. Communication through the moon with a telegraph is carried out in the site 144.010 - 144.100. WSJT - 144.100 - 144.200. On the usual days of communication, they are carried out by agreement - "SKED" or by chance "Random" as per square. agree or email or directly in " Chat "ah. In communication competitions only on Random. Communication procedure is as follows: in even minutes, the more oriental station transfers to the odd - Western. At the" SKED ", the reception / transmission period is increased to 2 minutes. In competitions reception / transmission - one minute. But strong stations working, as a rule, on CQ, can work arbitrarily as per square The signals reflected from the moon have strong and quite frequent fading, so the period in 1 minute will not seem large to you in many cases. The transfer rate is not more than 100 characters per minute. Digital Communication WSJT - JT65 is used in one minute. But this species requires a very accurate installation of the current time of the computer, the discrepancy in time should not exceed 1 sec. In the latest versions of the program, there is a possibility of adjusting time. Computer clock can be installed via the Internet http://www.atomtime.com. The largest number of lunar lovers is going during the contests. The largest contest - Arrl, which is held in two rounds to 48 hours, as a rule, in October and November, it also happens in December (as this year). The moon, of course, happens above the horizon, only in high latitudes. We have an average of 8-10 hours per day you can relax. Work on all ranges, but there are different categories: one operator is one range; one operator - many ranges; Many operators are one range; Many operators are many ranges. Types of radiation CW, SSB, WSJT. Multiplier: countries + US states + Canada province. Win in your category is very difficult, because In each category there are a number of "Big Ghanov" stations with huge antenna systems. In 2002, I managed to take first place in the category one operator - one range of 144 MHz, W5un was second. I fully appreciated the possibilities of a small antenna 4x15, but with two polarizations. True, before the second round I had to work pretty. During the day before the contest, the whole day sat on the mast, chopping the ice from the elements. And for the first time was lucky, both rounds took place in a rather calm magnetic setting. It should be borne in mind that magnetic storms, "Auroras", as well as on KV, have a strong effect on the connection through the moon, especially in the northern latitudes. Sometimes the passage is simply missing many hours in a row. The second contest - "European Worldwide Eme Contest" is carried out in spring together by French and German sides. It is also called Ref / Dubus EU EME Contest. Conditions for points and a multiplier are similar to ARRL, but there are no individual categories: one operator or a lot, all protrude or on one range or several. There is only a separate QRP and QRO. The next contest ARI happens in May or September. Italian contest is more democratic, there are many categories depending on the size of the antenna system. There is also a category "Cross" antennas in which I managed to take first place four times. Conditions of competitions are simple, 10 points for communication, 31 points for contact with the Italian radio station. Time and conditions can be found in Moon Net. You can subscribe to the Moon-Net at http://www.nlsa.com/nets/moon-net-help.html. The organizers led by I1ANP Mario are sent for first place in each subgroup of beautiful plaques. They also annually hold lunar conferences, on one of which I managed to visit. From Russian radio amateurs working through the moon on 2 m can be called: RX1AS, RW1AW, RA1ZC, RW1AY / 1, RK2FWA, UA3PTW, RV3IG, UA3MBJ, RK3FG, RZ3BA / 1, RA3AQ, RA3LE, UA3TCF, RA3QTT, RA3IS, RA3DRC, UA3DJG , RW3PF, RW3WR, RU3ACE, RX3QFM, UA4API, UA4AQL, UA4AAV, UA4ALU, RA4AOR, UA4NM, RZ4HF, RN6MT, RN6BN RK6MC, UA9FAD, RK9CC, UA9YLU, UA9SL, RV9JD. I think that with the advent of a new type of work WSJT, the number of our wells will grow, and will also be more participants in different competitions.

Communication with reflection from traces of burnt meteors exists in amateur and in professional communications. The most applicable are the frequencies of about 80 MHz. Therefore, radio amateurs of many countries, where the range of 50 MHz is allowed, is widely used. But the range of 144 MHz is more popular, where the main mass of VHF Earth works, although the range of 432 MHz is also used to carry out "meteor" connections. Meteors of different sizes fall on the ground every day and burned in the atmosphere, ionized plasma trails are formed, which are used for Reflections of radio signals. These traces are located at an altitude of about 100 km, the height and the magnitude of the trace depends on several factors, but primarily from the rate of meteor in the atmosphere. Meteorous communication can be used almost every day, because There will always be random - sporadic meteors. In fact, they can always be attributed to one or another meteor flow or rain. There are many threads that have their name http://vhfdx.ru/component/optioncom_frontpage/itemid.1. The name is associated with the constellation, from which this cosmic dust flies. Of all these streams, about 12 are the largest. Detailed information necessary for meteor lovers can be found on the OH5IY website, which also wrote a number of links. The radio amateurs of all over the world know the main streams and are actively working in them: these are quadrantides in January, Lyrida in April, Perside in August, Leonida in November, hemnides in December. Leonidah should be said especially. This flow in the usual years is characterized by a small number of meteors per hour, approximately 20, which is inferior to the number 100-110 - in the flows of perceid and hemnides. But in 1998, this light rain turned into a huge stream with the number of meteors\u003e 2000 per hour. These days, the radio amateurs could communicate with each other as on the KV, using mainly SSB. The main type of communication used to be a high-speed HSCW telegraph. Communication procedure is as follows: within 2.5 minutes there is a transmission at speeds from 1000 to 5000 characters per minute, on the receiving side there is an entry on a speed tape recorder or computer. The moments of receiving short reflected signals are noted (marked) and then listened at normal speed. German radio amateurs were developed by a digital tape recorder "DTR", which also allowed to restore the tone after division. A very convenient program of Win MSDSP2000 was written to the 9A4GL radio admission for receiving and HSCW transmission. And recently, to form high speed telegraph signals, a tonal manipulation method is used carrier in SSB mode, because The standard key key method in many transceivers allowed the speed not higher than two thousand signs per minute. HSCW is also used now, but the new type of digital communication FSK441 very quickly displaces it. This program for radio amateurs wrote the same K1JT. With its description, you can read it on its website and there to download it and the WSJT user manual in Russian, translated by Dmitry Ra3aq http://vhfdx.ru/component/option.com_frontpage/itemid.1

An example for new VHF Earths can be such radio amateurs, as Sergey Zhurtyayev RW3BP, which was the first of all on Earth on the ground reflected signals from the moon in the 47 GHz band. Alexander RN6BN recently installed an antenna system of 32 Cross-Yagi antennas. Antennas, cable connections, divisters are designed and made by Radiolink (RU1A). All questions for orders of the KV and VHF antennas The Tsya Elektronna addresses is shrinkled by ViD Spam Botiv. You prevail JavaScript, whisk of becoming їїї. . This is one of the largest antennas among the radio amateur antennas of the 144 MHz range. Dmitry RA3AQ leads an excellent site where you can find the necessary, as well as operational information to work at VHF. Recently, he set the antenna system 6x18 6.28 WL to work through the moon. VHF is not only MS and EME, but also such types of communication based on the reflection, scattering of radio waves of high frequency on the inhomogeneities arising in the troposphere, the Earth ionosphere. This is a well-known tropospheric passage of "Tropo"; Aurora, arising from the excitation of the magnetic field of the Earth; Sporadic passage of "Sporadic", formed by electronic clouds arising in the troposphere; "Iono" and others ... All these species are interesting, and compared with the passage on the kV less projected and more complex and thereby more interesting. It is both in the theory of information - the less likely the event, the greater the amount of information. About these types of communication is very written and our VHF, too. A lot of competitions of different rank are carried out at the VHF, which can also tell our active umbrella lovers. Alexander, RU1AA http://ra3is.qrz.ru/ra3is.files/eno1aa.htm

Detail Catagoria: UKC Activities Went: 24 Towness 2016 Markets: 1937

The moon is the nearest heavenly body to the ground. Its radius is 1737 km, weight of 81.3 times less than the mass of the Earth, and the average density of 3.35 g / cube. cm, i.e. One and a half times less land density. The duration of the lunar day is 29.5 Earth. The average distance on the Earth-Moon-Earth highway is 750 thousand km, attenuation of the signal on this path for the radio wave of the meter range is about 200DB, i.e. The signal is weakened at ten, in the tenth of times and goes there and back 2.5 seconds.

At the experiments, a 200 kW transmitters operating on a wave of about 2 meters and antenna with an amplification coefficient of 400 were used.
Great works in this direction were held in 1954-57 at Gorky University. Waves 10 and 3 cm were used for experiments, the directional action coefficient of antennas on a wave 3 cm reached 120 thousand, i.e. Energy concentrated in an angle of 0.5 degrees. As a result of these experiments, the reflection coefficient of radio waves from the moon was measured, which was approximately 0.25 - and it was found that the reflection comes from the central part of the visible disk of the moon. The experiments of the moon radar gave real soil to implement the idea of \u200b\u200busing the Moon as a passive repeater.
Interested in this idea and radio amateurs. And in July 1960, the first radio association was held in the range of 1296 MHz between American club amateur radio stations W6HB and W1BU. In 1964, the first radio communication was carried out in the range of 144 MHz between radio amateurs OH1NL and W6DNG.
In the Soviet Union, the first amateur radio communications through the moon was held on May 11, 1979 by the operators of the UK2BAS collective radio station, in the range of 432 MHz. Their partner was K2UYH. Later on January 19, 1981, the radio amateur UT5DL carried out the first radio communication in the 144 MHz band. His partner was K1WHS from Maine, having the largest antenna at that time (24 arrows of 14 elements).
On April 20, the same 1981, conducted his first radio and the author of this article (EX UB5JIN). And then went - went: December 6, 1981, the first intra-union radio communication (UB5JIN and UA3TCF), January 11, 1982 - the first radio communication from the territory of the USSR on SSB - (UB5Jin and K1WHS), August 15, 1982 First Communication with Japan (UB5JIN and Ja6dr), October 10 with Venezuela (UB5Jin and YV5ZZ) and so on ...
Today through the moon, thousands of radio amateurs of all continents of the globe in the ranges of 144, 432, 1296, 5600 MHz are carried away. Each of the ranges has its own characteristics, advantages and disadvantages.
Reception on the land of signals reflected from the moon, meets great fundamental difficulties:
The moon moves relative to the ground with a large angular velocity, so the reflected signal is subject to the "Doppler" effect, i.e. the wave reflected from the moving body has a frequency of oscillations other than the frequency sent by the wave. This difference for the 144 MHz range reaches 427 Hz.
The "Faraday" effect of the "Faraday" effect also has a big effect on the received signal, i.e. the rotation of the polarization vector of the transmitted signal, which is expressed in the deep fading of the signal. To eliminate this effect, antennas with circular polarization are needed, which are difficult to be carried out in the 144 MHz range from constructive considerations.
He strongly affect the reception of the signals of the meter range of cosmic noise, for example: the minimum noise temperature of the celestial sphere at a frequency of 136 MHz in February 1982 was 210 degrees of Kelvin or 2.35 DB at points of a minimum and 2750 degrees or 10.2 dB at maximum points.
Many problems are also associated with transparency of the troposphere and the ionosphere of land, atmospheric and local electrical interference.
Approximate attenuation on the Earth-Moon-Earth highway for different ranges can be expressed by the table: the position of the moon distance (thousand km) 144 MHz (DB) 432 MHz (DB) 1296 MHz (DB)
Perigue 356,334187,08196,6206,15
Apogee 406,610188,21197,76207,21

In order to overlap such a attenuation, a radio amateur who wants to engage in E-M-E radio communications must make very serious equipment and antennas. Based on the attenuation on the track and the well-known source data of the receiver and the transmitter, you can build an antennas amplification schedule for different radio wave ranges:

At: TX \u003d 700 Watts
Rx \u003d 1 DB
Df \u003d 100 hz
As can be seen from the schedule to obtain an echo of its signal with a level of 1 dB over noise in the range of 144 MHz, it is necessary that the antennas (transmitting and receiving) have in the amount of approximately 43 dB, i.e. A good antenna for E-M-E must have a gain of at least 21.5 DB. Although radio communications are possible when using an antennas with less amplification, so, for conducting radio communications with the radio amateur K1WHS (antenna 24 x14 and K.U. equal to 27DB) it is enough to have an antenna with a gain of 15-16 DB!
For a successful e-e-e-e work, you need to clearly know the position of the Moon, the time of its sunrise and enter you and your partners. The radio amateler needs to know the periods of perigete and apogee of the moon and the "windows" to Europe, Japan, South and North America. You need to know the days when the trajectory of the moon is close to the trajectory of the Sun movement, because conducting a radio communication with a difference of less than 30 degrees is impossible, For large noise emissions of the sun.
In the lunar work, an interesting phenomenon called "soil-effect" is also observed, i.e. at the rising and entering the moon there is a noticeable increase in the level of reflected signals per 1-3 DB. So, for the square "KN74BX", a pronounced effect was observed at an occurrence (In this direction, the plain 40-50 km ends with the Black Sea pool), at the rising "primer" was not observed (hilly terrain, turning into the Crimean Mountains).
A very interesting occupation when working through the moon is the conduct of echo tests. It is better to do outside the e-mne site (144.000-144.015 MHz). A series of points or dash is passed, the combinations of "bk", "Sk" are better perceived, an echo signal is accepted by about 2.5 seconds. It will be at the side of the frequency (Doppler effect) not more than 427 Hz. Echo not always audible and not constantly, it depends on the conditions. If at the moment the echo does not hear in your QTH - this does not mean that the signal is not reflected and is not accepted, for example, in Africa or America. Conversely - you can hear your partner well, your echo, and the partner at this point in time does not hear you. Experiments have shown that an echo with a level of 1-2 DB will be quite acceptable for E-M-ECH over noises taken from time to time.
The author of the article was carried out experiments with different antennas: 13 EL, 16 EL, 8X9 EL, 8X15 EL and preams on an antenna with a noise coefficient of 0.5 - 1.5 DB. The transmitter power amplifier was performed on two lamps 4CX350A on a two-stroke scheme (P Out ~ 1 kW). Experience has shown that such equipment, antennas and energy are quite enough for satisfactory work using signals reflected from the moon. During the year, radio communications were carried out with more than 100 different correspondents on 5 continents.
As mentioned earlier, the antenna systems for the reception of the E-M-E signals are one of the main factors. The antenna system should be rotated by the horizon, as well as the vertical element with the accuracy of the azimuth and element accuracy is not worse than 5-7 degrees. Strengthening the antenna system should be at least 18-19 DB. Antenna lattices based on antenna type F9ft: 8x9, 8x13, 4x16, 8x16, which are easily repeated and constructively simple are proven.
And finally, the antenna amplifiers, I would like to draw the attention of radio amateurs to a thorough scarpural setting, at least the simplest noise by the generator on the 2D2C lamp, because Little to put a good transistor, it is necessary to implement its technical parameters.
At the output of the receiver, it is desirable to connect a voltmeter (with an alternating scale) of the type B3-38, B3-39 in the experiments, to accurately measure the levels of E-Mes.

The abbreviated version of the article sent to the radio "Radio" on November 9, 1982.
Restored from the preserved Chernivikov, November 22, 2003, 21 years later !!!

Page 3 of 3

As soon as the moon began to rise high enough, experiments with echo signals continued. And on August 8, a new stage - Barry VE4MA accepted my signals. It was a sequence of dash with a duration of about 0.3 seconds and with a period of about 1 second. Three days later, my signals were accepted by all participants in the experiment. Unfortunately, all my attempts to take response signals from Gary Ad6FP did not give results. There was even a hint of the signal presence.

It should be noted that now the worst moment for ties through the moon, especially in the range of millimeter waves. Because of the large losses in the atmosphere, communication is possible only at large corners of the place. For EME QSO with North America, there is only 3-5 days a month, when the moon rises quite high, but these days now coincide with the apogee of the lunar orbit, which gives 2 dB of additional losses. In addition, these days are now a full moon, which corresponds to the maximum of thermal noise of the moon, in contrast to the lower-frequency ranges, in which the moon phase on the noise almost does not affect (the reflection there occurs at greater depth of the surface of the moon, where the temperature is quite constant), in The range of 47 GHz is observed more than a semi-armless change in the noise temperature of the moon. If we consider that the antenna pattern is fully fitted in the angular size of the moon, it is clear that its noise puts the limit to improving the sensitivity of the receiver. For this reason, I decided to abandon how to cool the low-noise amplifier. Technically, this is quite difficult to implement, and the maximum gain in the signal-to-noise ratio during cooling with liquid nitrogen could be 1-2 dB. Apparently such an increase was obviously lacked.

As a result, only one method remained - digital processing of the received signal. Unfortunately, well-known programs are not suitable in this case, since they are designed for narrowband signals of low-frequency bands. In our case, the width of the spectrum of the reflected signal reaches several hundred Hz. This is due, firstly, the multipath character of reflection from the moon, when each beam has its own Doppler frequency shift, and secondly, the signal fluctuations in the propagation of millimeter radio waves in the atmosphere. Since nothing ready to find was failed, I had to think about my own program. Here I was lucky again, my old familiar Vladimir Barchukov (http://www.orc.ru/~micron) agreed to help in this matter.

The first results were obtained on November 2, when it was possible to take from Gary AD6FP a series of "dash", and on November 27, it was possible to allocate both calls signs from noise (47GHz.wav). For the transmission, the usual Morse code was used in two-time frequency telegraph mode (BFSK), and for receiving the method of incoherent accumulation of repetitive information.

In this case, it was necessary to provide high accuracy of setting frequencies of the transmitter and receiver and the automatic correction of the constantly changing Doppler frequency shift throughout the session. After all, no possibility of adjusting the frequency on the real signal in this case is not. After the signal was highlighted, it turned out that the error was only about 100 Hz. A couple of years ago, it would be impossible, since there were no programs for the accurate calculation of the Doppler shift of the signal frequency reflected from the surface of the moon. Now there are such programs, and the most convenient of them is the latest version of F1EHN (EME System V5.1). It goes without saying that the accuracy of calibration of frequency in both correspondents is measured by dozens of hertz. For comparison, in a two-meter range, this corresponds to the accuracy of the frequency installation of about 0.1 Hz.

The analysis showed that the level of the received signal was OKO - 20 dB with respect to the noise power in the 2.5 kHz band (as was customary in WSJT). For comparison, such a "Avra-like" signal is practically not heard and is not visible using the Spectran program from about - 15 dB.

I suggested calling the MWCW program (Millimeter Wave CW). However, after appropriate finishing, it can be useful not only at millimeter waves.

Thus, all technical problems are mostly solved. It remains only to wait for a high moon, good weather and a certain proportion of good luck. And so that the equipment does not fail.

Check and configure the LBB on the desktop.

The idea to use the moon - the Earth satellite as a passive repeater came long ago. The first reflections of radio waves from the surface of the moon were obtained in 1946 by scientists of Hungary and the United States working in this direction independently of each other. At the experiments, a 200 kW transmitters operating on a wave of about 2 meters and antenna with an amplification coefficient of 400 were used.

"Mooner" antenna Alexander, RN6BN. 64 antennas 32 element.

Great works in this direction were held in 1954-57 at Gorky University. Waves 10 and 3 cm were used for experiments, the directional action coefficient of antennas on a wave 3 cm reached 120 thousand, i.e. Energy concentrated in an angle of 0.5 degrees. As a result of these experiments, the reflection coefficient of radio waves from the moon was measured, which was approximately 0.25 - and it was found that the reflection comes from the central part of the visible disk of the moon. The experiments of the moon radar gave real soil to implement the idea of \u200b\u200busing the Moon as a passive repeater.

Interested in this idea and radio amateurs. And in July 1960, the first radio association was held in the range of 1296 MHz between American club amateur radio stations W6HB and W1BU. In 1964, the first radio communication was carried out in the range of 144 MHz between radio amateurs OH1NL and W6DNG.

In the Soviet Union, the first amateur radio communications through the moon was held on May 11, 1979 by the operators of the UK2BAS collective radio station, in the range of 432 MHz. Their partner was K2UYH. Later on January 19, 1981, the radio amateur UT5DL carried out the first radio communication in the 144 MHz band. His partner was K1WHS from Maine, having the largest antenna at that time (24 arrows of 14 elements).

On April 20, the same 1981, conducted his first radio and the author of this article (EX UB5JIN). And then went - went: December 6, 1981, the first intra-union radio communication (UB5JIN and UA3TCF), January 11, 1982 - the first radio communication from the territory of the USSR on SSB - (UB5Jin and K1WHS), August 15, 1982 First Communication with Japan (UB5JIN and Ja6dr), October 10 with Venezuela (UB5Jin and YV5ZZ) and so on ...

Today through the moon, thousands of radio amateurs of all continents of the globe in the ranges of 144, 432, 1296, 5600 MHz are carried away. Each of the ranges has its own characteristics, advantages and disadvantages.

Reception on the land of signals reflected from the moon, meets great fundamental difficulties:

The moon moves relative to the ground with a large angular velocity, so the reflected signal is susceptible to the "Doppler" effect, i.e. A wave reflected from the moving body has a frequency of oscillations other than the frequency sent by the wave. This difference for the 144 MHz range reaches 427 Hz.

The effect of "Faraday" also has a big impact on the received signal, i.e. Rotation of the polarization vector of the transmitted signal, which is expressed in deep fading of the signal. To eliminate this effect, antennas with circular polarization are needed, which are difficult to carry out in the range of 144 MHz from constructive considerations.

He strongly affect the reception of the signals of the meter range of cosmic noise, for example: the minimum noise temperature of the celestial sphere at a frequency of 136 MHz in February 1982 was 210 degrees of Kelvin or 2.35 DB at points of a minimum and 2750 degrees or 10.2 dB at maximum points.

Many problems are also associated with transparency of the troposphere and the ionosphere of land, atmospheric and local electrical interference.

Approximate attenuation on the Earth-Moon-Earth highway for different ranges can be expressed by a table:

In order to overlap such a attenuation, a radio amateur who wants to engage in E-M-E radio communications must make very serious equipment and antennas.

EME antenna W5UN. 32 antennas 32 element.

To obtain an echo of its signal with a level 1 dB over noise in the 144 MHz band, it is necessary that antennas (transmitting and receiving) have in the amount of approximately 43 dB, i.e. A good antenna for E-M-E must have a gain of at least 21.5 DB. Although radio communications are possible when using an antennas with less amplification, so, for conducting radio communications with the radio amateur K1WHS (antenna 24 x14 and K.U. equal to 27DB) it is enough to have an antenna with a gain of 15-16 DB!

For a successful e-e-e-e work, you need to clearly know the position of the Moon, the time of its sunrise and enter you and your partners. This will help you to help computer programs, for example: WSJT and ORBITRON

The radio amateur needs to know the periods of the perigeuy and apogee of the Moon and the "Windows" to Europe, Japan, South and North America. You need to know the days when the trajectory of the moon is close to the trajectory of the sun, because Conducting radio communications with a difference of less than 30 degrees is impossible due to large noise emissions of the sun.

With lunar work, an interesting phenomenon is also observed, called the "primer effect", i.e. At the rising and entering the moon there is a noticeable increase in the level of reflected signals per 1-3 DB.

A very interesting occupation when working through the moon is the conduct of echo tests. It is better to do outside the e-mne site (144.000-144.015 MHz). A series of points or dash is passed, the combinations of "bk", "Sk" are better perceived, an echo signal is accepted by about 2.5 seconds. It will be at the side of the frequency (Doppler effect) not more than 427 Hz. Echo not always audible and not constantly, it depends on the conditions. If at the moment the echo does not hear in your QTH - this does not mean that the signal is not reflected and is not accepted, for example, in Africa or America. Conversely - you can hear your partner well, your echo, and the partner at this point in time does not hear you. Experiments have shown that an echo with a level of 1-2 DB will be quite acceptable for E-M-ECH over noises taken from time to time.

As mentioned earlier, the antenna systems for the reception of the E-M-E signals are one of the main factors. The antenna system should be rotated by the horizon, as well as the vertical element with the accuracy of the azimuth and element accuracy is not worse than 5-7 degrees. Strengthening the antenna system should be at least 18-19 DB.

And finally, the antenna amplifiers, I would like to draw the attention of radio amples on a thorough scarpurous adjustment of the preamp. Little to put a good transistor - it is necessary to implement its technical parameters.

As part of its program project WSJT, Joe Taylor, K1JT, developed JT65 to work EME as WSJT extension. The bulk of radio amateurs (if not all) is now carried out by EME - QSO's using this program and very successfully. Please visit the site k1jthttp: //www.physics.princeton.edu/pulsar/k1jt/wsjt.html. This digital communication mode apparently gives a gain in the signal-to-noise ratio of about 10 DB compared to CW and makes much easier to conduct a larger than EME QSO low-energy station than it would be possible using CW (except situations with the best conditions) .

EME - KB8RQ antenna.

Some excerpts are taken from the article by Vasily Beketov, UU2JJ (EX UB5JIN) - Moonlink at 144 MHz.

Widowed through meteors, I decided to try to spend at least one EME - the connection. Experience with the WSJT program was already large and equipment, as it would be theoretically allowed, to work with Big Gun's-Ami (radio amateurs with large energy and a whole system of directional antennas).

For that period of time, I had an ICOM IC-910H with a 100 watt output power on the 144 MHz band, the ICOM AG-25 preamp, 4 of the 10 elements of each (A144S10 of Diamond, Japan) and turning Yaesu G-800 DXA.

The first connection decided to spend with Alexander, RN6BN - as louder (both in CW and SSB) and stronger in the level (according to the WSJT program), I no longer accepted anyone!

To cause it began fashion JT65 specifically without prior arrangement (Random connection) and he answered without any problems. The first my EME - QSO took place !!!

It was strongly encouraged by me and now I was looking forward to the sunrise and coming the moon. So, as I had an antenna without the possibility of Elevation, I was given it, approximately 1 hour in order to try to communicate when the moon is low above the horizon.

In addition, the "soil effect" helped very strongly, when additional 1-2 Dcs were added to the main signal as a result of the reflection of the signal from the Earth.

The second connection was without problems with W5Un, the third with KB8RQ and so slowly-little girl "went" ...

For 1 year I spent more than 50 EME - connections (of course with "large stations"). To work and further through the moon, it was necessary to improve their setup accordingly. But as it always happens in life: the lack of finance, the restriction in the area for installing the antennas, interference with the neighbors because of the high power of the amplifier, in the end, the heat was cooled. But the immeasurable joy and the feeling that you can still have something on this sinful earth, I experienced a full ...

73!