RTL-SDR for VHF Marine Scanner on SDR#


Recently I was approached for advice on frequency scanning. My first thought was a traditional approach of starting at the base frequency, stepping by the channel spacing and doing a power evaluation. If greater than a threshold, then hold and attempt a decode. Before building a prototype in GNU Radio, I thought I would look at current SDR scanners to see how they operated. In this post I will look at SDR#/FMS Frequency Manager Suite.

VHF Marine Band

Channel #Ship Tx Freq MHzShore Tx Freq MHz
0..step 50KHz156.000160.600
16156.800 (distress)156.800 (distress)
60..step 50KHz156.025160.625
Wx Channels161.650/161.775/162.400
Fig.1 Marine VHF Frequencies

Figure 1 shows a table of Marine VHF radio band frequencies that cover from about 156 – 162 MHz (varies between countries) and are assigned to Channels 0 – 88 (Ref.1).

SDR#/FMS Scanner

Fig.2 Frequency Manager Suite Scanner Menu in SDR# PlugIns

In previous posts, I have covered using SDR# which is an extremely versatile SDR receiver software that works well with the RTL-SDR (Ref.2). The latest version at the time of writing is 1901 and can be downloaded from Ref.3. In order to perform the scanning function, there is a versatile Plugin “Frequency Manager Suite” that can be added to SDR# (Ref.4). Download the zip file, unzip and read the installation instructions. Then unzip the next file and place the folder in the SDR# directory folder “Plugins”. Previously, to add Plugins it was necessary to add a “magic line” to an xml config file. This is no longer necessary.

Figure 2 shows SDR#_1900 with the FMS PlugIn installed. The Frequency Scanner menu is very straightforward. You can configure a group of channel frequencies via buttons F1-F10 (say Marine frequencies that you want to continuously monitor) or scan a range of frequencies in this case 157 – 162.4MHz. There is a detailed instruction manual contained in the second unzipped file and you can configure all the scanner parameters in the “Tools” menu. Figure 3 YouTube Video “” shows the operation.

Fig.3 YouTube Video RTL-SDR for VHF Marine Scanner on SDR#

Please send your comments, questions and suggestions to:

YouTube Channel
YouTube Channel


#1. – “Marine VHF Radio”,

#2. – “RTL-SDR for VHF Air & Marine Bands”,

#3. -“SDR# Download”,

#4. – “Frequency Manager Suite for SDR#”,

By Jeremy Clark

Jeremy Clark is a Senior Telecommunications Engineer and Advanced Amateur Radio Operator VE3PKC. He is the author of E-Books on Telecommunications, Navigation & Electronics.