Radio Delta AM modulation meter and monitoring equipment in the broadcast chain
Shortwave tests

Technology & Updates

Transmitters, antennas, audio processing, monitoring and real listener data — the Radio Delta AM technical workbench.

Transmit → monitor → collect reports → compare → improve.

Shortwave radio as a practical workbench

Shortwave changes by season, time, antenna, receiver and propagation. Radio Delta AM combines transmitter checks, remote monitoring and listener reports to understand what really works on air.

Live listener technology data

What listeners are using

Reception reports show more than where the signal arrived. They also show which receivers and antennas made reception possible.

Analysing listener technology data…

Receiver & antenna share

A practical overview of receiver brands and antenna types found in confirmed reception reports.

Receivers

Receiver brand share

Receiver names are grouped by brand or category.

Example: Kenwood R-5000 counts as Kenwood; ICOM IC-7300 counts as ICOM.
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Antennas

Antenna type share

Antenna descriptions are grouped into practical categories.

Full antenna descriptions remain visible in recent listener setups.
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Propagation from real reports

Propagation patterns from listener reports

These charts show which bands are reported by month, when listeners report in UTC, and how far each band usually travels.

Real radio, measured by real listeners

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Reports analysed
Valid listener reports.
Strongest DX band
Average distance by band.
Peak listening hour
Reception report times in UTC.
Seasonal band pattern

Which bands work through the year?

Reports grouped by month and band.

75m 49m 31m 25m other
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Wider segments mean more reports for that band in that month.
Listening times in UTC

When shortwave comes alive

Reports grouped by UTC hour.

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Band versus distance

How far each band usually travels

Average listener distance gives a simple view of each band.

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Distance is only one part of the story. Local noise, antenna type, receiver quality and time of day also matter.

Recent listener setups

A few technical reception examples from the listener database.

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Radio Delta Knowledge Desk

Technical themes for deeper articles and future updates.

Propagation

Frequency & band tests

A shortwave frequency depends on season, time, distance, solar conditions and noise.

Antennas

From RF power to useful coverage

Height, angle, ground system and band choice decide how transmitter power becomes field strength.

Transmitters

Carrier, modulation and reliability

AM needs a stable carrier, clean modulation and reliable RF behaviour.

Audio

Processing for shortwave AM

Processing must improve clarity and intelligibility without making the signal tiring to hear.

Monitoring

KiwiSDR and recordings

Remote receivers and off-air recordings show how the signal behaves away from the transmitter site.

Listener data

Reception reports as measurements

SINPO, distance, time, receiver and antenna data help compare real reception.

Current working model

Detailed broadcast times belong on the Program Schedule page. Technically, Radio Delta works with seasonal anchor bands: 49 metres in summer, 75 metres in winter, and 25 metres for special DX broadcasts.

Looking for times and frequencies? The current on-air planning is listed on the Program Schedule page.

View Program Schedule

How we test a shortwave broadcast

A good test compares several sources before drawing conclusions.

1

Choose the band

Season, time, expected coverage, QRM and earlier reports guide the choice.

2

Monitor locally

Carrier, modulation, audio level and RF behaviour are checked at the station.

3

Check remotely

KiwiSDR and off-air recordings show the signal across Europe.

4

Compare reports

SINPO, distance, receiver, antenna and time are compared with monitoring results.

Technical Spotlights

Classic transmitters, processing and experiments that shaped Radio Delta.

Rohde and Schwarz SK050 transmitter setup used by Radio Delta AM
Transmitter history

R&S SK050 with the Orban 9200

48 metre band · Rohde & Schwarz SK050 · Orban 9200 processing

A stable HF workhorse from the Radio Delta archive, preserved close to its broadcast character.

Breakaway software audio processing used for Radio Delta AM audio processing tests
Audio processing

Breakaway software processing

AM audio · clarity, loudness and punch

Software processing showed how much clarity and presence could be shaped before the transmitter.

Telefunken S2525/3 shortwave transmitter used by Radio Delta AM
Shortwave transmitter

Telefunken S2525/3 on air

1 kW continuous output · 1.5–30 MHz

A practical and reliable shortwave transmitter with stable coverage and strong audio performance.

Rohde and Schwarz SK080 AM broadcast transmitter refurbished by Radio Delta AM
Vintage broadcast engineering

R&S SK080 refurbished

Built in 1959 · tube-based · 800 watts RF

Classic broadcast engineering: heavy, analogue and full of AM character.

Technical archive: older transmitter, antenna and audio processing posts remain part of the Radio Delta technical history.

Explore all Technology & Updates

Build along: videos & experiments

Real checks and real on-air results.

Transmitter / RF build & checks

Practical steps, measurements, audio-to-RF, modulation and monitoring.

On-air testing & monitoring

Real on-air runs, practical checks and listener feedback.

Help improve the signal. Send a reception report with SINPO, receiver, antenna, location and frequency.

Send a reception report