Jose Jacob, VU2JOS
Rajkot is the 4th largest city in Gujarat State and is also the name of a district located in Western part of India. A few days back in July 2012, I had the opportunity to visit the Super Power Transmitting Station of All India Radio, Rajkot by prior appointment. The transmitter and allied infrastructure is located in a large single story building in a 160 acre campus at Liyare village in Paddhari Taluk, 38 kms South of Rajkot on the nice State Highway No.25 to Vadinar. There is a bus stop called Akashwani in front of the station.
Three brand new solid state transmitters of 400 kW of S7HP model made by Thomson Broadcast, France capable of pumping out 1200 kW power has been installed here this year by Engineers from France along with their counter parts from AIR. These transmitters are capable of broadcasting in DRM, AM and simulcast modes. It is a Relay Station used by External Services of AIR beamed to nearby Pakistan, Afghanistan, Iran etc in NW direction. As far as I know, this is the most powerful broadcasting station located in South Asia.
Tests have been in progress since April 2012 in various modes during day time at various times especially around 11.00 am to 1.00 pm local time. The frequency is 1071 kHz for AM mode and 1080 kHz for DRM mode. On April 6 & 7, 2012 efficiency tests were conducted by transmitting programs continuously for 24 hrs. (How come all of us missed that one?!.) In AM mode it can radiate up to 1200 kW while in Simulcast mode it is capable of 836 kW and 550 kW if it uses only DRM mode. During tests, Urdu Service and Vividh Bharati programs are being broadcast and sometimes music from the emergency studio of the station. When we visited the station at noon, tests were in progress with music from the emergency studio. They are using a Murphy Richards receiver for monitoring DRM and a small Philips Bahadur transistor for checking AM mode.
The antenna is a self radiating mast made by ECIL, Hyderabad along with 3 other towers serving as reflectors 156 Meters high. It is very high and can be seen from long distances. Before the transmitter is put on, a siren is blown to warn the people in the vicinity of the antenna. The antenna can be operated in directional or omni directional pattern. Separate electricity lines are there to the station with a 66 kV electrical sub station. There is a generator for the essential services but the transmitter does not have any back up power in case of electricity failure.
Some of the equipments found there were: Combiner unit for the 3 transmitters, Huge Dummy Load, Comcon Audio Rack, 9400 Digital Optoimode AM, Belar AM Modulation Meter, 2 nos of Satellite Receivers SCPC V004 from Space Application Centre. The Emergency Studio temporarily consists of a Studio Master Air 6 console. All the allied equipment are brand new or has been nicely refurbished recently. They use water cooling for the transmitters. We don’t find any knobs on the transmitter and there is only a touch screen and controlled by computers.
When the station is ready it is expected to be using Simulcast mode with 1071 kHz in AM and 1080 kHz in DRM.
The old schedule which is expected to continue is as follows on AM mode
0015-0100 UTC Urdu
0100-0200 UTC Sindhi
0200-0430 UTC Urdu
0830-1130 UTC Urdu
1230-1500 UTC Sindhi
1500-1600 UTC Baluchi
1600-1930 UTC Urdu
The Vividh Bharati Service will be there in DRM mode on 1080 kHz.
The station is technically ready and is awaiting recruitment of new staff. If everything goes well, it may be in regular service after some months.
The station has a separate office in the city as follows to which reception reports can be sent:
Super Power Transmitter
All India Radio
The transmitters of the Regional AIR Rajkot Station are located at different sites away from the Super Power Transmitter.
When the old transmitter was in use, they used to issue QSL cards directly from the station. The officials were amused at seeing my QSL card of their old transmitters. Similar transmitters are being set up at Mogra, near Kolkata also now to replace their old 1000 kW transmitter.
A bit of history about the old Super Power transmitters at Rajkot ….
The regular transmissions started from here on 1st July 1971 with 2 x 500 kW transmitters from RIZ (Radio Industrija Zagreb) which was in use for 32 years till 2003, although its recommended life is 20 years. It broadcasted the External Services in Urdu, Sindhi and Baluchi beamed to nearby Pakistan. It first used 1070 kHz which was later changed to 1071 kHz in the Medium Wave frequency re-shuffle on 23rd Nov 1978. On 27th August 1991, a plane crashed into one of the towers and one of the masts collapsed. Since then it was operating only in omni directional pattern with one mast while the other remaining two masts were grounded. Due to non availability of spares, from 6th Sept 1994, only one of the 500 kW transmitters was in use. The old transmitters were dismantled after 2004 and new transmitters were installed in the same spot this year. Needless to say, the new Solid state transmitters occupy much lesser space than the old Valve transmitters. The entire building and campus had a facelift now due to the installation of new transmitters. Lot of laborers were seen working in the campus.
A large staff photo taken in June 1971 is displayed prominently on the corridors of the station near the entrance with the heading “Lest we forget”.
It is heartening to note that while many stations are closing down on MW, AIR is installing such mammoth transmitters.
Photo of transmitter courtesy : http://www.thomson-broadcast.com
Station History Summary:
1 July 1971 2 x 500 kW RIZ Tx 1070 kHz
23 Nov 1978 Frequency changed to 1071 kHz
27 August 1991 A plane crashed into Antenna Tower and damaged one tower
6 Sept 1994 Only 1 x 500 kW txer in use from this day
2003 Shut down of old transmitters
2012 Installation of 3×400 kW S7HP Tx on 1071 AM Mode & 1080 kHz DRM
Photo’s of new 1000 kW MW transmitter at Rajkot http://tinyurl.com/8zgrnlo
Jose Jacob, VU2JOS, National Institute of Amateur Radio, Raj Bhavan Road, Hyderabad 500082, India. Email: firstname.lastname@example.org