12 Apr 2015

antenna matching

In order that the antenna operates over a wide range, it is necessary that it has a broadband and is compatible with the power line. In turn, the supply line (feeder) has been aligned with the output of the transceiver. For this purpose, the device must agree diagrams of various matching devices for transmitters and receivers can be found at this link

about the circuit boards

Here I want to tell you how hams manufactured circuit boards chemical method. Actually I myself rarely use this method and use milling and cut a small circuit boards for their amateur construction with a cutter made of saw blade scalpel and clamp the soldering iron. Cut the workpiece desired size Stripping fine sandpaper cover with circuit board solder clamp clamp and cut the track. Maybe it turns out not so beautiful but so quickly and reliably, and errors in the manufacture of an easy fix. Almost all of his amateur design and sometimes I have collected and now collect so. Read about the chemical manufacture of circuit boards in the home, you can click on this link

11 Apr 2015

HF and VHF amateur radio antenna and matching devices

An antenna is a device for transmitting electromagnetic energy from the supply line into the free space and vice versa. Any antenna has an active element - the vibrator and besides the vibrator may passives vibrator and the reflector. The active element is connected to the power line. Passive components form the electromagnetic field of a certain structure providing the necessary directional
properties of the antenna. Also provide alignment with the power line. Application of additional elements also enables to get more gain in gain compared to a single antenna. With the help of a lot of element antenna can not only get a win to be strengthened, but also filter out the signal from the unwanted noise coming from different direction. Under ideal conditions, the passage (propagation), short wave reception can be conducted at a regular piece of wire several meters long. But such conditions are not so often. But if everyone did such conditions were formed, the reception quality is not determined by the antenna and the receiver circuit (ie its characteristics selectivity, sensitivity and stability). Typically hams used for one antenna of the transmitter and the receiver, the most practical than single antenna receiver transmitter. If you use two identical antennas for the transmitter and receiver and near, in this case, the input of the receiver may be severe interference, induced by its own transmitter.

An antenna is a device for transmitting electromagnetic energy from the supply line to free space and vice versa. Antenna dares active element - the vibrator , an antenna may also contain passive components (one or more). To the active element of the antenna connected power line . When the alternating voltage supply line around the active element ( vibrator ) , a magnetic field. Passive antenna elements are needed for the formation of the magnetic field of a certain field of the structure and formation of the directional properties , impedance matching system " space - antenna power line .
The antennas can be categorized into three groups : linear antenna aperture antennas, surface-wave .
Linear antenna - is a regular cable or wiring system . Radiation is determined by the spread of linear antenna currents on its wires and their mutual orientation. This group includes the rhombic antenna vibrator . These antennas are often used in the square -wave range .
The next type of antennas is aperture antenna ( reflector antennas , parabolic ), these antennas are characterized by the presence of surface ( aperture ) , which is a transformation of energy propagating in the supply line to the radiation energy . Typically, the size of the aperture is significantly larger than the wavelength . Radiation of this antenna is determined by the structure of the electromagnetic field on the aperture .
And another group is a surface wave antenna . The emission of these antennas plays the role of a surface wave . It extends along the antenna part in the process of radiation. Antenna radiation is determined by the way of connecting to the power supply line and the condition of wave propagation along the antenna . Representative of this group is the antenna Uda - Yagi .
The antenna system is simply a collection of separate antennas. Application of the antenna system increases the possibility of the formation of the desired patterns . The antenna system provides a higher gain compared with a single antenna for enhancement (in level signal)

4 Apr 2015

my equipment

Software-defined radio - radio transmitter and / or receiver, using technology that enables the software to set or change the radio frequency operating parameters, including, in particular, the frequency range, modulation type or output power, except for changing the operating parameters used in the ordinary course with a predetermined radio presets, according to the particular specifications or system.
ERP performs a significant part of digital signal processing on a personal computer or on a FPGA. The aim of this scheme is a radio transmitter or radio arbitrary, changeable by software reconfiguration.
Software radio is a great utility for military applications and wireless services, as it allows to serve a large number of radio protocols.
Equipment for ERP usually consists of a superheterodyne receiver, which converts the signal from the radio frequency to an intermediate, analog-to-digital and digital-to-analog converters (ADCs and DACs).

my amateur radio receivers and software used for monitoring the work of the radio station >>>

ham radio receivers

ham radio receivers