contesting je psychicky a v prípade viac ako niekoľkohodinových pretekov aj fyzicky náročný. Pretekať v plnom nasadení, v každom okamihu na 100% – vyhľadávať stanice, volať výzvu, logovať, obsluhovaťTCVR and other accessories, changing strategy,… so we'll make it easier.
Improving reception in contests
A serious contesting enthusiast will certainly be interested in improving reception.. The ability to receive quickly and smoothly is a key factor for success in racing. This feature can be improved by regular participation in races, but also technically - by using special antennas for reception and improving the properties of the receiver. Since almost all commercial transceivers have a receiver constructed as a superhet by the filter method, it is the properties of the filters that greatly affect its properties.
NF filter on the receiver output
The cheapest is the addition of an NF filter connected to the receiver output.. CW filters are mainly used, since the standard MF filters are relatively wide. More expensive NF DSP filters offering multiple filtering options (LP, HP, BP, notch, NR) will help especially in specific situations, for example, they help pull a weak signal out of noise.
Effect of MF filters and roofing filter in the receiver
Quality MF filters are not a cheap matter, and it is worth spending time on the right selection before purchasing. We are interested in the bandwidth for -6dB, for -60dB (the ratio of these two data is the filter coefficient determining steepness) and stopband. Crystal filters have better properties than electromechanical filters, but they are not available for all devices. In the world of contesting, INRAD filters are a term. After installing the filter, do not forget to activate it in the menu or adjust some parameters according to the manual.
I would like to draw the attention of interested parties to the material on INRAD filters by Milan OK1VWK: www.sweb.cz/ok1vwk
Correct settings in the service menu
In connection with the device settings, it sometimes happens that the user incorrectly sets some menu item out of ignorance.. This mainly concerns changes in the service menu, but incorrect settings of the DSP filter can also lead to the conclusion 'well, it doesn't work'. When consulting settings with a more experienced colleague, have them explain what each parameter means and what impact it has on the properties of the device. Analyses by DK9VZ can assist in choosing a suitable device. http://dk9vz.com/rx.htm
Use of preamplifiers
The use of preamplifiers is useful for VHF. The usual noise figures of VHF transceivers are relatively high, and by adding a preamplifier, we have the possibility of real sensitivity increase. However, this should not be at the expense of robustness. The gain of such a preamplifier is therefore set to only a few decibels. Otherwise, signals will enter the transceiver at a much higher level, resulting in an increase in intermodulation products. An example can be the FT-857/897, whose sensitivity in the 70cm band significantly increases when a preamplifier is connected.
Final stages – power amplifiers
A very good alternative to PAs with bipolar transistors are PAs with V-MOS transistors. These FETs operate at safe voltages and their properties are much better.For a very interesting price, for example, a 600W kit is offered. www.communication-concepts.com (Some VHF PA are mixed into HF on the website. After adding a source and low-pass filters, it is possible to realize a powerful PA at an acceptable price.)
Tube PAs are popular in our region due to the low price of tubes. The disadvantage is the more complex mechanical construction, the need for tuning when changing frequency (to HF), and life-threatening voltages. The advantage is the great durability of the PA and decent suppression of harmonic frequencies.
"Reliable source" is also an element that determines comfort in contests. In contesting, the source is stressed more than in normal operation, so we pay attention to prevent overheating of the transformer, diodes, or voltage regulators. It is good to test a new source before the first contest.
Accessories for contesting
PSV The meter/wattmeter is a common measuring instrument in the ham shack. If we do not use a PA or tuner, we can manage with what is built into the TCVR. Entire articles have been written about this measuring instrument, and many constructions are certainly not accurate. But even such an indicator is better than none – it gives a good feeling that "power is going out."
A headset is almost a necessity for SSB. With a handheld microphone, it is possible to contest only while keeping a paper log.Writing on a keyboard with a microphone in hand is quite impractical. A headset with a microphone also positively affects optimal modulation, as the constant distance from the mouth is maintained. The cost of the headset + foot switch + a simple switch for an electret microphone costs hundreds of crowns. Those who are wealthier can also opt for professional sets, e.g., Heil.
Electronic keys, elbugs, serve not only to improve the transmitted CW signal. An elbug with memory allows sending predefined texts, e.g., a call.. If we consider how many times the call is sent during a contest, the advantage of the elbug is evident. More advanced keys allow sending special texts, such as automatically increasing connection numbers.
There is a device capable of automatically sending a call for the Fonia. They are CQ-keyers, in English digital voice keyer, abbreviated DVK. They are based either on digital audio memory or use a PC with suitable software.
Using a computer for contesting
The PC has become established in the ham shack of the radio amateur. The computer can function as an elbug, DVK, DX cluster, control the transceiver but above all keep a log. The DX cluster represents 'many ears from around the world that provide real-time information about stations on the band.'. In the case of connecting the control of the TCVR from the PC, we can thus retune with one click and make a station that you might have missed.
During contests, any self-announcing (spotting one's own call sign) in the DX cluster is prohibited. However, such advertising is allowed before contests and even appropriate. Various bulletins and special websites serve this purpose. In addition, the practice of skeds - agreed connections - is customary. It is mainly used on VHF bands, where due to the difficulty of making a connection, arranging skeds during contests in the form of chat, e.g., via ON4KST chat, is also practiced.
Atalanta Locator OK1DUO
Is very popular in our regions log from OK1DUO - Atalanta Locator. It has spread mainly due to its understandable language, good stability, and over the years has also created an extensive database of callsigns. It supports VHF contests and OK/OM HF contests. Its disadvantage is running in DOS, which brings certain problems in the era of more modern operating systems.
N1MM log
Other used contest logs
Other used contest logs: Penguin, SD, TACLog, VUSC, WriteLog, VHFCTest4Win.
Glossary
to log - to record connections in the log
superhet - a type of receiver where the signal is first converted to an intermediate frequency at which it is easier to filter and amplify, then it is detected and amplified to output for headphones or speakers
NF filter - low-frequency filter
MF filter - intermediate frequency filter
DSP filter - digital filter
HP - high pass, high pass filter - allows signals above the set frequency, suppresses signals with lower frequency (high pass)
low pass filter - allows signals below a set frequency, suppresses signals with higher frequency
band pass filter - allows only signals of a specified part of the frequency spectrum
notch filter - suppresses one frequency, e.g. squealing
noise reduction filter
stopband - maximum attenuation of the filter in the stopband
intermodulation products - undesirable products of the receiver - phantom signals that arise from the interaction of two or more strong signals
final stage - amplifier followed only by the antenna
QRO - code referring to high power
TVI - abbreviation for television interference
SWR meter standing wave ratio meter
wattmeter - power meter
Elbug - electronic key for transmitting telegraphy
DVK - automatic call generator (digital voice keyer)
logbook - used for recording contacts (callsign, reports, exchanged code, etc.)
DX cluster - database of stations heard on the band in real-time
spotting - sending information to the DX cluster
next time: what didn't fit into other sections - something about operations