Vatican Radio

Vatican Radio

Vatican Radio transmitting DRM on 1611 kHz using their medium wave transmitter at Santa Maria di Galeria, near Rome.
These broadcasts are receivable here in the UK as no radio stations use this frequency within the UK.
 

 

 

 


Here is the reception log (shown graphically) of two night-time DRM test broadcasts from Vatican Radio that I received. The first report was a Mode A transmission with a 16.3 kbps data rate and the second report (three days later) of a test broadcast in Mode B with a 15.2 kbps rate. The red line is signal strength and the blue line shows audio frames decoded.

Frequency        1611 kHz
Label            Vatican Radio
Bitrate          16.32 kbps
Mode             A
Bandwidth        9 kHz
SNR min: 0.0, max: 21.3

Radiotext - D.R.M. MW test transmission from Vatican Radio 1611 KHz Santa Maria di Galeria radio station "Rome".


Frequency        1611 kHz
Label            Vatican Radio
Bitrate          15.24 kbps
Mode             B
Bandwidth        9 kHz
SNR min: 0.0, max: 22.2

Radiotext - This is a DRM MW test transmission from Vatican Radio 1611 KHz Santa Maria di Galeria radio station, "Vatican City".


Care has to be taken when comparing two different sets of readings taken on different days as propagation conditions can be different. However the highest SNR recorded for each day is very similar 21.3dB compared to 22.2dB.

As can be seen from the time axis reception is not possible before 21:15 UTC (22:15 local time), presumably the entire path must be in total darkness before the conditions are right for sky wave DX conditions. The radio path is about 1500 km from Rome to the UK.

Assuming reception conditions and signal strengths was very similar for these two days a comparison between the two SNR readings is shown below. The Mode B signal (shown in green) produced a better SNR than the Mode A broadcast (shown in red).

This should not come as a surprise as Mode B is a more robust mode designed for skywave propagation and selective fading. Mode A is specified for groundwave MF operation rather than HF propagation.

[Screen shots using DRMcalc analysis software written by Carsten Knutter]