Technology & Station News
Transmitters, antennas, audio processing, monitoring and practical engineering — the technical workbench behind Radio Delta AM.
Radio Delta AM on shortwave
Radio Delta AM currently operates with up to 1,000 watts RF output on 5970 and 3985 kHz, and 500 watts RF output on 12085 kHz. Separate antenna systems are used for the 75, 49 and 25 metre bands. Frequencies, UTC times and seasonal planning remain on the Broadcast Schedule page.
Turning RF power into useful coverage
Antenna height, geometry, orientation and band choice determine how effectively transmitter power reaches listeners.
Shortened V at 10 metres
The 49 metre antenna is a shortened V with two legs of approximately 8 metres and an apex height of approximately 10 metres.
Inverted V at 20 metres
The 75 metre antenna uses an inverted-V arrangement with an apex height of approximately 20 metres.
5/8-wave vertical and dipole
Radio Delta AM can use both a 5/8-wave vertical antenna and a dipole antenna for broadcasts on the 25 metre band.
Processing for shortwave AM
The current HF chain uses Orban 9400 processing. The goal is clear speech, musical impact and a controlled modulation envelope that remains comfortable to hear.
Practical results over theory alone
Models and calculations support planning, but Radio Delta AM always compares predictions with real monitoring and confirmed listener reports.
From studio to listener report
Radio Delta AM treats the complete signal path as one technical system.
How we test a shortwave broadcast
A reliable technical conclusion combines station measurements, remote monitoring and listener evidence.
Prepare the system
Audio chain, transmitter, antenna and monitoring equipment are checked before the broadcast.
Monitor locally
RF output, modulation, audio quality and transmitter behaviour are checked at the station.
Check remotely
KiwiSDR, WebSDR and off-air recordings show how the signal behaves across Europe.
Compare reports
SINPO, location, receiver, antenna, distance and time are compared with the monitoring results.
Measuring what reaches the listener
Technical quality is judged at the transmitter and at real reception locations.
Remote receivers
KiwiSDR and WebSDR receivers help compare reception in different parts of Europe.
Spectrum and waterfall
Spectrum checks reveal bandwidth, sideband balance, splatter and modulation behaviour.
Listener recordings
Off-air recordings provide direct evidence of clarity, fading, interference and audio impact.
See how the signal was actually received
Receiver share, antenna types, band patterns, UTC reception times and reported distances have their own live dashboard.
Technology updates and engineering stories
Future antenna work, transmitter changes, processing tests, monitoring results and practical experiments will be published here and in the Technology Updates archive.
Latest station updates
Current transmitter, antenna, processing and monitoring news.
Open archive →Listener Analytics
Live reception patterns, receivers, antennas, UTC hours and distance statistics.
Open dashboard →Send technical feedback
Reception reports with SINPO, receiver, antenna and audio help improve the station.
Submit a report →Transmitters and experiments that shaped Radio Delta AM
These systems belong to the Radio Delta technical history and do not necessarily represent the current on-air chain.
R&S SK050 and Orban 9200
A stable HF workhorse and an important part of the earlier Radio Delta broadcast chain.
Telefunken S2525/3
A practical and reliable shortwave transmitter with approximately 1 kW continuous output capability.
R&S SK080 refurbished
Tube-based broadcast engineering from 1959, restored as part of the Radio Delta technical archive.
Breakaway software processing
Earlier software-processing tests explored clarity, loudness and punch before transmission.