Work in VHF Competitions
VHF radio communication is a discipline of radio sport. The number-code of the sports discipline in the All—Russian Register of Sports is 1450081811YA. It includes an exercise on conducting two-way radio communications in the VHF, UHF and microwave radio frequency bands (conventionally called ultrashort wave, VHF) with other participants of sports competitions using their own radio station (receiving and transmitting equipment, antennas).
Contesting (synonym – radio sport) competitive work on the air carried out by radio amateurs. Amateur radio stations participating in the competition, from which both individual operators and teams can work, try to conduct the maximum possible number of communications with mutual exchange of information in a limited time interval. The rules of the competition determine the amateur radio bands used, possible types of work and the composition of messages used in the exchange. Connections made in competitions determine the number of points by which participants are ranked.
Sponsors of competitions publish their results in magazines or post them on Internet sites.
The contest was developed (along with other amateur radio activity) in the 1920s – 1930s. Due to the simplification of transatlantic ties, the conditions of the competition were formed according to the principle of establishing the greatest number of connections with different countries of the world. The aim was also to implement practical messaging on long routes in emergency conditions. Over time, the number and variety of tests has increased significantly, which is why many radio amateurs put contesting at the head of their amateur radio activities.
So, to start working in VHF competitions, you need to have the main thing - desire. Everything else will follow.
Even if you have mistakes at the beginning, it's okay. The main thing is to draw conclusions and try not to allow them in the future. Our colleagues and friends participate in the competitions, so they will help and tell you!
Technic. Antennas and a VHF transceiver.
Antennas
On your own From my experience (I have been working in VHF competitions since 2016), I can say that for a full-fledged work in the "contest" for a beginner "radio athlete", 9 e-yagi at 144 MHz and 13 e-yagi at 430 MHz are enough. (this is a minimum, a classic) There are a lot of proven options for repetition on the Internet. For example, the version of the antennas of the world-famous amateur radio DK7ZB tested by me https://www.qsl.net/dk7zb/start1.htm
5-7 years ago in VHF competitions we worked in FM, SSB, CW modulations. Now practically no one works in FM modulation, SSB and CW remain, respectively, the polarization is horizontal.
A very important moment in VHF! No RG-58 or TV cables for 25 rubles! Use at least 5d-FB or better 8d-FB, 10d-FB (do not be afraid of new prices, Used in good condition can be found 2 times cheaper) pre-tuned to the desired frequency and as short as possible to avoid losses.
According to Rothamel's theory, a mast of 2 wavelengths is enough, in principle, the correct statement
but, a large mast height in VHF will be an advantage (do not forget about the cable length ratio, without fanaticism).
I used the height of the mast with a length of 6 meters, because in the metal shop the maximum length of the pipes was 6 m.
At the very top of the mast had 144 MHz just below 430 MHz
Equipment.
Here's what there is, a single-band transceiver is suitable for a start, but if there is an opportunity to purchase a multi-band VHF transceiver of 144/430 Mhz, the power will usually be 20-25 Watts, there are options and 100/75 watts, respectively, and the price is higher. The most popular VHF transceivers of our time are Kenwood TS-2000, Kenwood TS-790, Icom-910 Icom, 706MK2G, I recommend the latter option, not bad for a start!
Of course, it is better to use a gasoline/diesel generator as a power source for the equipment. 1 kW.
Place to work
More interesting in every sense from the field. You can choose a slide with a clear horizon (so that the antenna does not rest against the wall of the forest, fields, etc.), drive away from the city - less noise, more points
It's easier - from home or from the cottage / garden or some other stationary place. But perhaps this place will be in the lowlands, the horizon is closed, interference and something else.
The essence of VHF competitions
For a certain time, you need to make as many connections as possible over as long a distance as possible.
Thus, score the maximum number of points. Points are awarded for kilometers. At 144 MHz - 1 point per km, at 430 - 2 points, 1296 MHz - 4 points (sometimes this is not the case - here you need to read the regulations on the competition, but the order is the same).
The distance is calculated automatically by the judging program and your log on the computer, if you use it based on QTH locators.
A QTH locator is a conditional square that allows you to determine your location, the distance to you, and the azimuth of the antenna with acceptable accuracy. You can find a QTH locator of the place from where you will work by using numerous services on the network. For example https://qth.herokuapp.com/
During the competition, you need to make a connection and record its data:
Range
1. Date.
2. UTC time.
3. The call sign of the correspondent.
The control number given to the correspondent and its QTH locator.
5 The control number received from the correspondent and its QTH locator.
Any error in this data will lead to the fact that the judges will not count this connection in both correspondents.
The time difference can be no more than 3 minutes. (again, it depends on the refereeing)
Important! Before the test, you need to check the clock, do not make a mistake with UTC. It is necessary to transmit and indicate in the report the QTH locator from which the work is being carried out. And then they used to indicate home
Control number - on VHF, this is the serial number of the connection. You should not skip numbers and retransmit them. Numbering goes separately by ranges, starting with the number 001.
I strongly recommend taking a laptop, modem or phone with you to distribute the Internet over WIFI.
You will need the Internet for VHF chat, you can download and get acquainted at http://www.vhfdx.ru/
Another important point
Before participating in the competition, announce your desire on local amateur radio forums
You can also report on special services https://vhfcontest.ru/contest it's interesting to see what kind of equipment colleagues use to work in competitions. There is also an interesting service - search for correspondents within a radius of X kilometers. Enter your square, from which you will work, the value of the radius in kilometers, and look in the table and on the map - distances and azimuths, a very cool thing.
You need to tell the call sign, how you will work, the QTH locator, ranges, type of radiation (CW, SSB, FM), antennas, equipment, telephone for communication.
How to keep a log (hardware log).
After the competition, you will need to send a report. This is mandatory. Even for 1 QSO, you need to write a report and send it to the judging panel. Not sending a report is depriving your correspondent of points for contacting you. And his lost time. Or maybe it was these points that he did not have enough to win a prize or fulfill the discharge standards. In general, the rule is: if you have worked in competitions, you have sent a report.
The simplest thing is to write
If there are not many correspondents, repeats can be tracked by a piece of paper. And in the field it's easier than a laptop.
I usually prepare a table with already declared correspondents for each range. I write my square on it - so as not to forget while working. I make a sign: time, call sign, transmitted number, received number and received locator.
I write the date and the modulation in the middle of the line.
Since the numbering of links is separate for each range, each range has its own sheet.
It is more convenient to log on a computer (laptop). R4NAF is better suited for VHF https://r4naf.ru/soft-log/ I used this log to make reports. Stuffed with paper.
That's actually all.
At the end of the article, I want to say that VHF radio communication is very interesting for its unpredictability, sporadic passes to Europe are possible in June and July, I managed to catch a Sporadic one in 2017. 12 QSOs with stations LZ, YO, I, Z3, TA, SV, which added points to the total.
Well, there is no limit to perfection, for effective participation in VHF competitions, TOP teams travel to densely populated areas (the border of the Rostov and Voronezh regions) with directional multi-element antennas and masts with a height of 12-17 meters, a power of 1 kW and take prizes.
In conclusion, a few photos.
Good luck, 73! R7TJ Vadim