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Ebook – Amateur Station Operators Certificate (India) – Objective type questions

Ebook – Amateur Station Operators Certificate (India) – Objective type questions Author: D.Prabakaran  Any individual above the age of 12 can became a ham in India after qualifying in Amateur Station Operators Certificate examination. The Officer-In-Charge, Wireless Monitoring Station, Dept. of Telecommunication under Ministry of Communication & Information Technology, Govt. of India is the authority …

Video – AIR MW DRM Reception

All India Radio chennai -A DRM digital transmission reception at my listening post in Krishnagiri Receiver – MSI SDR with long wire antenna. Location – Krishnagiri 635108 Equipment – MSI.SDR Dongle Software –Sdruno 1.4 & DREAM Decoder Antenna – 66 feet Longwire antenna tuned for amateur bands Video – AIR RAJKOT DRM Reception

Circuits – DARK ROOM TIMER

The timer circuit described here provides a pleasant musical tone in your darkroom at 1-second intervals.The circuit takes up very little space and can be easily converted into a metronome. Unijunction transistor (UJT) T1 functioning as a relaxation oscillator triggers the phase-shift audio oscillator circuit built around transistor T2, turning it on and off. As …

Circuits – Short Wave Transmitter

This transmitter circuit operates in shortwave HF band (6 MHz to15 MHz), and can be used for shortrange communication and for educational purposes. The circuit consists of a mic amplifier, a variable frequency oscillator, and modulation amplifier stages. Transistor T1 (BF195) is used as a simple RF oscillator. Resistors R6 and R7 determine base bias, …

Circuits – Easy To Build AC Power Meter

If your goal is to save on electricity, you must first measure the ac current flowing through your appliances. The formula for power is the product of the ac line voltage and the measured current. Presented here is a demonstration of how to build an ac power meter using a current transformer (see the figure). The …

Circuits-VHF Preamplifier using Max2633

Here is a high performance RF amplifier for the entire VHF band that can be successfully built without any special test equipment. The grounded -gate configuration is inherently stable without any neutralisation if reasonably good layout techniques are employed. The performance of the amplifier is quite good. The noise figure is below 2dB and the …

Technical Article -Tutorial on Spread Spectrum Technology

Author – D.Prabakaran Spread spectrum technology has blossomed from a military technology into one of the fundamental building blocks in current and next-generation wireless systems. From cellular to cordless to wireless LAN (WLAN) systems, spectrum is a vital component in the system design process. Since spread-spectrum is such an integral ingredient, it’s vital for designers …

30MDG Membership

30 METRE DIGITAL GROUP MEMBERSHIP VU3DXR

  My special thanks to 30 Meter Digital Group for allowing me in as member. I am one of Group of Amateur Radio operators and Short Wave Listeners with a common interest – 30 meter (10MHz) HF band activity.