--- layout: base.njk title: KST4Contest – ON4KST Contest Client for VHF, UHF and SHF description: KST4Contest combines ON4KST chat, candidate prioritisation, sked planning, AirScout data and logger integration in one desktop client. heroFx: true visitorCount: true ---

ON4KST contest workflow for 144 MHz and above

KST4Contest

KST4Contest is an ON4KST client for VHF, UHF and SHF contest operation on 144 MHz and above. It keeps active stations, frequencies, skeds and aircraft-scatter opportunities in view while connecting chat information with logger and station interfaces.

The client helps the operator choose the next useful station and prepare the next operating step. It does not automate the radio contact itself.

Contest information ready for the next decision
Active stations and QRGs Chat messages, recognised frequencies and known bands stay connected to the station.
Skeds and AP windows Scheduled contacts and AirScout timing remain visible while the contest continues.
Logger and station status Worked information, the current TRX QRG and rotor direction inform the same workflow.
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Practical tasks

From chat traffic to the next operating step

Messages, station activity and station interfaces provide different pieces of the same operating situation. KST4Contest brings them together where they are needed.

Keep track of chat and active stations

Follow messages across two ON4KST categories, see active bands and keep recognised frequencies attached to the callsign that sent them.

Select and plan contacts

Use filters and priorities to find candidates, schedule skeds and keep their timing visible in the timeline together with AirScout data.

Connect logger and station components

Synchronise Worked status with supported loggers and pass useful context to the TRX, rotator and local DX Cluster interfaces.

What the chat data showed

Useful detail makes a reply easier

Archived ON4KST chat logs from several IARU contests in the preceding two years were analysed. The concrete example comes from the July 2025 contest and combines the 144/432 MHz and Microwave categories. It compares sked requests with the replies and sked windows they produced.

The text analysis considered action and sked words, frequency, timing, beam direction, aircraft-scatter information, locator, mode and courtesy or anchor words. Within this sample, requests containing AP and beam information were associated with an almost 30% higher chat reply rate than short, unspecific requests such as “Hi noname, try 2m?”.

This measures chat replies, not completed QSOs. It is a correlation within the investigated sample, not general proof of causation and not a promise that an individual sked will succeed. The practical point is modest: information that can be used immediately saves the other operator from having to ask for it first. KST4Contest supplies part of that context when preparing messages and skeds.

Source: Marc Fröhlich, “Chat-Mining: Jagdinstinkte wecken mit KST4Contest”, conference paper for GHz-Tagung Dorsten 2026, section “Erfolgsrezept”. Read the background and download the paper.

Selected functions

The parts most often used during a contest

These examples show how station, band, message and timing information is used in practice. The complete function overview remains available for configuration details and less frequently used tools.

Chat overview and station filters

Separate global and private views keep the traffic readable, while station filters narrow the candidate list without hiding the underlying chat context.

Priority and band opportunities

Candidate scores combine available station information with Worked and band state so that a useful next call is easier to find.

Skeds and AP timeline

Manual skeds, reminders and aircraft-scatter windows remain visible instead of disappearing in the continuing chat stream.

AirScout and path information

AirScout data adds timing and path context to a selected station without turning that assessment into a propagation promise.

Open the complete function overview

Limits

A priority score is not a propagation forecast

Priorities are not a propagation forecast. Scores, filters and AP windows depend on the data available to the client. They help with sorting and timing, but they do not guarantee a QSO.

Project status

Stable for operation, Nightly for testing

Stable is the normal choice for contest operation. Nightly contains the latest development state and is intended for testing. Changing versions immediately before a contest is still not recommended.