Industrial Training in All India Radio

In this vacation, we(me and Anil CS, my class mate) planned to go to All India Radio for the Industrial Training. It was a 5 day program. I am not attempting to publish a technical report on this because I am too lazy to do so and AIR(All India Radio) technical details cannot be revealed much without the permission by the Government of India. Also restrictions are there in capturing photoes of inner side macines and electrical connections. So we got only the picture of the main gate Akashavani and the Transmitting station residing at avanoor. You can see the 122m long MW antenna (630Hz) on the picture of Avanoor Transmitting station. It is propagating a power of 100kW. An old 20kW antenna is there in Akashavani, but it is not using now. Most of the technical details are kept secret because of the security reasons. But they tried to explain maximum technical details to us. They opened old 20kW propagation station for us, but they were fully build up of large triodes, tetrodes, etc. Some of the valves were very costly, but I didn't like it much because, I usually play with transistors and integrated chips. They were not working for 10 or more years and were dusty. Next day, we went to Avanoor 100KW transmitting station. It was much more sophisticated.
I am not trying to describe a lot about AIR, but here I give an overview. The programs are recorded and live programs are set up and edited at Akashavani, Ramavarmapuram. Since there is no active antenna, the program is transmitted through FM. It is short range, but enough to receive the signal at Avanoor. They said that probably we can hear programs in 103MHz FM also from near Avanoor. I tried it in my home, but failed. They also provide microwave (Micrwave is default medium, FM is used if microwave transmission failed.) transmission in addition with FM.

About random numbers

Nothing is random in this world. But something feels to be random if we do not consider some of the associated parameters. If we consider all parameters (ideally), and can feel things in every perspective, it becomes a definite process. The lack of determining the parameters associated with a process is the reason why some process likely to be random.
For example, consider a coin is tossed, it appears a random process to get an outcome of 'head' or 'tail'. But if we simulate the whole process in a computer oriented mechanics simulation program, the process definitely depend upon the orientation of the coin while tossing and air friction, gravity, and so many other things. It is clear that one can say definitely what will be the outcome of the toss. Then why are you saying that it is random? All called random process definite in the other kind. Nothing is random. Nothing should be random.

Software install problem in Nokia E65

My nokia E65 is cute and smart, but had some problem while installing softwares inside it. It uses symbian OS. I googled about this problem and searched several forums and found that, only some mobile phones in this series has this problem. While installing a software (.jar , .jad or .sis, .sisx files), a progress bar appears and an error "Unable to install" appears while the progress bar becomes almost complete.
The solution is to upgrade the firmware inside your E65 and restart your mobile. Now my E65 is really smart!!!
Steps to upgrade your mobile phone firmware(This is applicable to almost all nokia phones)
1) Download Nokia updater software from nokia website. Here is the download link:
http://europe.nokia.com/get-support-and-software/download-software/device-software-update/download
2)Install nokia updater in your OS.
3)Back up your data in mobile phone using backup utility in the Nokia PCsuit. No need to back up the data in the memory card.
4)Check your mobile phone is fully charged in order to ensure that, it will not switched off during update process
5)Start Updater.It will detect your phone while connected to PC via cable and automatically download and install firmaware.
6) Do not unplugg PC cable during the installation process.It will cause severe damage.
7)Copy the data from backup after successful installation

8)Try install software now, it will surely be installed.
Good Luck!

Learning something from exams!!!

Last week, I have electronics lab exams. I went as usual and got a simple experiment to form a wave form as shown in figure using clipping, clamping and rectifier circuits from a sine wave. The frequency of input sine wave was not given so that we can choose a convenient frequency. I drew appropriate circuit which I was studied earlier and got "proceed" command from the external examiner to do it.

I quickly build circuit on bread board and double checked it. Then input is taken from signal generator and output is fed to CRO. I gave all power supplies and swtched on Vcc to circuit, CRO and signal generator. Alas! signal is different. I rechecked my circuit again and again but no use. I got a signal like this.


But the required signal is different.. First half cycle is Ok. But second halfcycle is clipped off. I couldn't understand what's the reason. Wasted a lot of time by rearranging the circuit components and adjusting the knobs of signal generator and CRO.The actual signal required is also given.Chances were going to be worse. Started to troubleshoot it from one corner, I realised that the bridge rectifier circuit using four 1N4007 diodes is the problem centre. I rechecked all the diodes using multimeter, but no use. At last, I replaced some new diodes, no use.. I passed a simple sinewave through the circuit, again second half cycle is clipped off. All diodes are correct. There is only 10 minutes to complete exam. Dresses become wet even under the fan in full speed. Nothing to do more than return the components. But I prayed GOD, what a destiny. Then I got an idea to replace the signal generator by a transformer directly from power supply since the frequency os oscilation was not given. I just replaced it, but got the correct answer. Really- but had some noise, its not a probelm. I comleted exam within 5 minutes and showed correct output.
Actually what may be the reason? May be some evils playing inside the signal generator. But I think some strong reasons are there. In the case of signal generator, there is no negetive voltage exists to forward bias the dioes in the bridge rectifier even when we 'feel' some negetive effect on CRO. No use by adjusting 'offset' knob in the signal generator. That effect only occur in the CRO display, but not in physical.