We resently bought several Asus X200 series netbooks for our faculty members. The main attraction of this cute netbook is its light weight and a built in HDMI port. We plan to use them extensively for content delivery in class rooms. These machines are really cheap, costing around Rs17000 ( around $260). The base model… Continue reading Wireless on Asus X200M netbooks: Ubuntu 14.04 LTS
I have been toying with the idea of making a Si5351A breakout board ever since I saw the chip details on Silicon labs web site. It seems SI5351A is an ideal choice for Variable Frequency Oscillator (VFO) for a homebrewed radio. The SI5351 is an i2c programmable any frequency clock generator. The chip can generates… Continue reading A simple Si5351A breakout board
I have been trying to program cheap Chinese DDS modules recently. I wanted to add a DDS VFO to one of my bitx rigs. These modules are available at $4.5 from aliexpress. They claim that it can work up to 40Mhz. I used an arduino Uno along with a rotary encoder for controlling the module. The… Continue reading Plug and Play DDS VFO with arduino
by R. Jayaraman (VU2JN) This article is a sequel to the article “A Compact ATU handles 100 watts” that was published online in March 2011. It describes a Norcal-type Antenna Tuning Unit with an in-line Stockton-bridge-type Reflected-power Indicator that I built recently (April 2011). This ATU is also capable of handling the full output of… Continue reading ATU with REFLECTOMETER
by R. Jayaraman (VU2JN) This note describes a compact Antenna Tuning Unit (ATU) that I assembled recently. It is capable of handling the full 100-watt output of my FT-840 transceiver. For efficient radiation of the RF power otput of a HF transmitter, its output impedance, the characteristic impedance of the transmission line (usually coaxial cable),… Continue reading A compact ATU handles 100 watts