Getting started with contesting – part four

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, obsluhovať TCVR 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.. Schopnosť rýchlo a bezproblémovo prijímať je kľúčovým faktorom pre úspech v pretekoch. Táto vlastnosť sa dá zlepšovať pravidelnou účasťou v pretekoch ale tiež technicky – používaním špeciálnych antén na príjem a vylepšovaním vlastností prijímača. Keďže takmer všetky komerčné transceivery majú receiver konštruovaný ako superhet filtrovou metódou, sú to vlastnosti filtrov, ktoré jeho vlastnosti výrazne ovplyvňujú.

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

A better effect is achieved with MF filters.This is because the sooner we remove disturbing signals in the receiver, the more we 'lighten' the subsequent stages of the receiver, which then process the desired signal more easily. For this reason, so-called roofing filters are also available.

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.

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.. Týka sa to najmä zmien v servisnom Menu, ale aj nesprávne nastavenie DSP filtra môže viesť k záveru „veď to nefunguje“. Pri konzultácii Settings so skúsenejším kolegom si nechajte vysvetliť, čo ktorý parameter znamená a aký má vplyv na vlastnosti zariadenia. Pri výbere vhodného zariadenia môžu napomôcť analýzy DK9VZ https://dk9vz.com/index.php/Home/trx-messwerte

Use of preamplifiers

The use of preamplifiers is useful for VHF. Obvyklé šumové čísla VHF transceiverov sú pomerne vysoké a zaradením predzosilňovača máme možnosť reálneho zvýšenie citlivosti. To By však nemalo byť na úkor odolnosti. Zisk takéhoto predzosilňovača preto nastavujeme len na niekoľko decibelov. Inak sa do transceiveru dostanú signály v oveľa väčšej úrovni, čo rezultuje v zvýšenie intermodulačných produktov. Príkladom môže byť FT-857/897, ktorého citlivosť v pásme 70cm výrazne vzrastie pripojením predzosilňovača.

Final stages – power amplifiers

I recommend using the final stage only to more experienced radio amateurs.. It also depends on the performance categories of the race, whether it makes sense to invest in QRO from a tactical point of view and also from the perspective of possible TVI.Commercial PA with bipolar transistors usually have problems with imperfect bias sources, which are a big problem especially for surrounding radio amateurs. Some time ago, an excellent bias source for these PAs was described on the web. OK2KKW described an excellent bias source for these PAs.

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/eb104/ (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.'

The vast majority of competitors prefer listening with headphones, or for SSB, headphones with a microphone, headsets. Ergonomics are essential – headphones must fit snugly but comfortably on the head. The price is not a deciding factor.

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 -dávače, v anličtine digital voice Keyer , skrátene DVK. Tie sú založené buď na digitálnej audiopamäti alebo využívajú PC s vhodným programom.

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. Rozšíril sa najmä vďaka zrozumiteľnému jazyku, dobrej stabilite a v priebehu rokov aj vytvorenia rozsiahlej databázy značiek. Podporujete VHF contesty a OK/OM kv contesty. Jeho nevýhodou je beh v DOS-e, čo v ére modernejších operačných systémov prináša určité problémy.

N1MM log

A representative of the new generation of logs is N1MM. Je to veľmi variabliný denník pod OS Windows. Cez Telnet umožňuje pripojenie do clustra, dokáže ovládať TCVR, má DVK, bandmapy, podrobné štatistiky, atď. Podporuje všetky veľké kv a VHF contesty, z našich contestov je priamo podporovaný len OK/OM DX contest. Contesty, ktoré nepodporuje si môže užívateľ (s dobrými počítačovými znalosťami) doplniť. Kvôli výhodám, ktoré tento log má a zjednotenému ovládaniu, som takto doplnil OM AC contest a SSB Ligu – aj keď s drobnými obmedzeniami.

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