Friday 29 January 2021

MEDIUM WAVE BROADCASTS IN INDIA BY All India Radio




MEDIUM WAVE BROADCASTS IN INDIA BY All India Radio
Indicative locations of MW DRM transmitters in India shown in map

In the list, the DRM frequency and the AM carrier is 9 kHz lower. Programme content of AM and one of the channels of DRM is the same.

Vividh Bharati Service is also known as VBS. Regional programme variants are indicated by city name after the network title.

Note : Operates in Pure DRM mode 1530-1630 hrs. (India Standard Time) every day except Sunday

Broadcasts will have local coverage during daylight hours but generally cover long distances during darkness.

for more details:https://www.drm.org/what-can-i-hear/broadcast-schedule-2/

 

Monday 11 January 2021

RTL-SDR Blog R820T2 RTL2832U 1PPM TCXO SMA Software Defined Radio with 2x Telescopic Antennas

 


RTL-SDR TUTORIAL: DECODING DRM RADIO

Digital Radio Monodial (DRM) radio is a type of digital shortwave radio signal that is used by international shortwave radio broadcasters. It provides superior audio quality compared to AM signals by using digital audio encoding. With an upconverter, good antenna, and decoding software the RTL-SDR software defined radio can receive and decode DRM signals. This tutorial is also applicable to other software defined radios that can receive HF with or without an upconverter, such as the HackRF, Airspy, Softrock and Funcube dongle.

Examples of DRM Decoding
YouTube user Superphish shows DRM reception with his Ham-it-up upconverter, and rtl-sdr.



Tutorial: How to Receive and Decode DRM Signals
To receive DRM with RTL-SDR, you will need the following:

An RTL-SDR dongle working with SDR#. (Or a more advanced SDR such an Airspy)
An HF upconverter such as the recommended SpyVerter or ham-it-up, or a dongle modded for direct sampling (such as our already modded V3 dongle), or SDR# modded to use the experimental Oliver Jowett HF driver for regular RTL-SDR dongles.
The DREAM DRM decoding software with AAC decoder.
Virtual Audio Cable or VB-Cable.
A DRM signal looks like this (left) on the waterfall, placed next to a normal shortwave AM signal (right).

We will assume that you already have an HF capable SDR, such as the RTL-SDR V3 or an HF upconverter, and have set it up with SDR#. We also assume you already have an audio piping utility such as Virtual Audio Cable or VB-Cable set up on your system which allows the audio to be passed from SDRSharp to the decoding software. If you don't have and not set these up, check out the Buy RTL-SDR and Quickstart pages, and head to the virtual audio cable download page (trial), or the VB-Cable download page (free).

The sampling rate of your audio piping method must be set to 48000 samples/sec. To set this in Windows, right click your device in the Windows sound recording tab, go to properties and under the advanced tab, set the sample rate to 48000 Hz. Do the same to the same device under the Playback tab as well.
 
Sound Properties
Now, head to the DREAM download page, download DREAM and extract the zip file into a folder. DREAM is a free opensource DRM decoder.
 
Due to software licence reasons the required audio decoder can not be shipped with the DREAM binary file. You can follow the instructions on the download page to compile your own faad2_drm.dll decoder, but as not everyone has compilation experience, a precompiled faad2_drm.dll download for windows can be found at this megaupload link. Note that using this file in some countries may not be legal due to patent laws. Place the faad2_drm.dll file into your DREAM folder.
 
Now you can open SDRSharp, set virtual audio cable as the output audio device, and then tune to a DRM signal. DRM signals use upper side band (USB), and have a bandwidth of 10 kHz, so apply these settings to SDRSharp as well.
 
Carefully align the left red line with the start of the signal. AGC can be left on, but it may need to be experimented with in order to get the best decoding performance.
 
Now, open DREAM and then go to Settings -> Sound Card -> Signal Input -> Device and set Virtual Audio Cable or VB-Cable as the input device. Also, ensure that Settings -> Sound Card -> Signal Input -> Sample Rate is set to 48000 Hz.
 

Try to get the green "Level [dB]" bar in DREAM to be near the center by adjusting the volume settings in SDRSharp. If everything is set up correctly, you should see three green bars underneath the volume meter and start seeing information about the DRM radio station you are tuned to in the window, and also begin to hear some audio.


Some Tips:
To receive DRM signals you will need a good HF antenna, placed up high. A simple long wire strung across your attic may work well. Look up "random wire antenna". Also a magnetic loop antenna may be a good choice.
RTL-SDR tends to place imaged broadcast AM signals into some DRM signals. This can cause decoding to completely fail. We suggest trying a HF filter that blocks the AM broadcast band.
If you hear no audio when decoding, check that you have placed faad2_drm.dll into the DREAM folder correctly.
DRM is a digital signal, so it will either work and play audio or it will not work at all. Poor reception may cause the audio to constantly drop out.

Friday 8 January 2021

Digital channels of Prasar Bharati see over 100% growth

 



Digital channels of state broadcaster Prasar Bharati across Doordarshan and Akashvani have registered more than 100% growth in 2020, clocking over a billion digital views and over six billion digital watch minutes, the government said in a statement on Sunday.


During the year, NewsOnAir App added more than 2.5 million users with the platform registering over 300 million views. Live radio streaming, with over 200 streams, emerged as the most popular feature.

Underscoring the substantial digital audience for news from the region, the north east service of All India Radio News is also in the top 10, and has crossed the 100,000 subscribers online.

The Mann Ki Baat YouTube channel and Twitter handle have seen rapid growth in 2020, the government said with the latter having more than 67,000 followers and the former including regional language versions of different episodes featuring the PM’s address. Around 1,500 radio plays in different Indian languages are available across the DD-AIR network which are now being digitised and uploaded on its YouTube channels. Several hours of educational content and teleclasses are now available on the broadcaster’s YouTube channels in different Indian languages.

Friday 1 January 2021

A new generation AM - Digital (DRM) - FM receiver GR-216


 

GOSPELL GR-216 MULTI-BAND RADIO

A new generation AM - Digital (DRM) - FM receiver
GR-216 Technical data

With special features:

1. Record The B'cast. It is possible to record and play back audio files to and from a USB memory stick. The function works for all modes (AM, FM and DRM) and will be stored on the USB stick under a directory named "grrec".

2.With the release of the v460 firmware it is possible to create DRM logs which can be plotted with the latest version of the DRM Log-Plotter.

GR-216 Technical data at a Glance
Frequency range, FM: 87.5 - 108.0 MHz
Frequency range, AM: 531 - 1620 kHz (522 - 1710 kHz with v421M)
Frequency range, SW: 2.3 - 26.1 MHz
Tuning step 50 kHz or 100 kHz
MW: 1 kHz or 9 (10) kHz
SW: 1 kHz or 5 kHz
Antenna FM & SW: Telescopic antenna
MW: Ferrite antenna
Active antennas on MW and SW
External Antenna sockets FM: BNC
AM & SW: BNC
Internal / External antenna switch.
Station memory slots: 60
DRM memory slots (VM): 200
Tuning system: Manual (rotary knob)
Auto-scan (Up / Down)
Preset buttons (VF)
DRM Memories (VM)
Tone controls Bass
Treble
Mid
Stereo reception: Headphones or Line Out connectors
Clock: 24 Hour clock, dual Alarm clock (radio or buzzer)
Sleep timer.
Display: Multi-function LCD.
Power supply, internal: 230V / 50 Hz AC
Power consumption Normal use: 13 Watt
Stand-by: 7 Watt
Power supply, external: 9 V DC
Power consumption Normal use: 5.6 Watt
Stand-by: 0.7 Watt
Loudspeaker 77 mm Ø
AF output power: 4 W
Measurements (without knobs): 240 mm (w)x 120 mm (h) x 150 mm (d)
Weight (total): 2155 g
Weight (230 V power supply): 705 g
Supplied accessories: 230 VAC power cord
230 VAC / 9 VDC power supply
User's manual

For more details:https://www.hobbyradio.se/en/drm/gospell_en.html