Radio communication transceiver is a radio transmitter at the same time the plane doubles as a radio receiver used for communication purposes.
It consists of the transmitter and the receiver are assembled in an integrated way. In mulamula generation, the transmitter or receiver or transmitter and receiver sections are assembled separately and is part of a stand sendirisendiri and can work well sendirisendiri Currently employed both parts are integrated in turn.
Aircraft simple transmitter consists of an oscillator generating radio vibration and this vibration after vibration boarded with our voice, in a technique called dimodulir radio, then by the antenna is converted into radio waves and transmitted. As we know that the sound waves we can not reach long distances, although its power is quite large, while the radio waves with a relatively small force can reach a distance of thousands of kilometers. In order for our voice can reach a far distance, then our voice superimposed on radio wave radio results from the vibration generator, called a carrier wave or carrier and the carrier wave was going to deliver our voice to distant places.
In a place far earlier, the radio waves emitted by the antenna received our speaker. By the antenna, radio waves had, in the form of electromagnetic waves is converted into electrical vibrations and into the receiver.
In our speaker receiver plane, vibration and vibration carriernya then discarded and then raised our voices be accommodated through the speakers. With this technique it is possible modilasi an audio vibrations reach a far range.
We sound vibrations enter the transmitter through a microphone, microphone output was often needs to be strengthened first with an audio amplifier is called a microphone preamplifier can be superimposed on the carrier for the modulator.
To increase the transmission power of a transmitter, vibration of the oscillator was before the emitted amplified first with a radio frequncy amplifier. Strengthening can be done once and can also be done more than once. Transmitter is not reinforced is called a level transmitter and the reinforced one called two-level and beyond. In general, to reach 100 Watt transmit power need to strengthen the 3 times, the first amplifier is called predriver, the next amplifier called the driver and final amplifier called the final amplifier.
Block Diagram of SSB Transceiver
If we're talking about the Single Side Band, then we touched more on amplitude modulation (AM). At each modulation we do we actually do the mixing between the radio frequency to audio frequency. Any mixing of two frequencies will occur the second summation process and at the same frequency reduction process occurs from both frequencies.
So every time we memodulir carrier, will produce two frequencies at once. For example, a carrier with a frequency of 3000 Kc we modulir with audio ferkuensi 3 Kc, the result is 3003 Kc and Kc 2997, or said occurred two sides of the band is the upper side and lower side. The top side and bottom side are shaped symetris, so if it is a direct result of modulation we mean we memancarakan exude the same two goods.
If we shine the way mentioned above, we use the mode is said to Double Side Band (DSB) because the carrier that includes top and bottom sides are emitted together. In factory-made plane, this mode is usually coded in terms actual AM radio is the DSB technique.
We know there are two kinds of ways to make the SSB, the first way is by phase shift method, another way is by filtering methods. The first way is not widely used and factory-made aircraft SSB generally use filtering.
Signal DSBSC, before the amplified and transmitted, is inserted into the SSB filter in advance to produce LSB or USB. Filters are used for this purpose is filtering crystal or mechanical filters. SSB transmitter is said to be more efficient than AM (DSB), we can give this picture as follows. For example transmitter AM (DSB) with power 150 Watt (100% modulation depth), then power on the USB and LSB respectively and the carrier has a 25 Watt 100 Watt power. We know that the audio side we are on the band. In the SSB emission, emitted only one side band LSB or USB is a powernya only 25 Watt.
With SSB 25 Watt beam, the audio we have to arrive at destination with the same clarity of information with jet AM (DSB) 150 Watt earlier.
Another advantage of SSB is the wide-band mode that can be more narrow. For the purposes of communication, SSB mode requires only the band width of about 3 Kc, while the DSB mode takes about 6 Kc, thus providing savings SSB mode the use of the band.
In the detector a SSB receiver, the received signal must be mixed in advance with the frequency of the outcome of a Beat Frequency Oscillator (BFO) and used as the BFO carrier oscillator.
Homebrew QRP SSB Transceiver circuit 80m Band
In general, the transceiver has the following block diagram, basically Transceiver tebagi into three main parts: Part VFO and BFO Part Transmitter (transmitter) and Section Receiver (receiver), where there are some special blocks that are used for both paths are either transmitter or receiver. Simply in this transceiver merkit Use the tools that we only Multi tester, RF Probe, SWR and Power Meter, Tone Generator Af 1Kc and multi-band Radio HF SSB to function as a monitor frequency BFO, VFO, monitor Balanced Modulator Exciter at once both the transmitter or receivers .
Data Transceiver:
Frekwency Range: 3700 Kc a / d 3900 Kc
Mode: LSB Singgle conversi
IF: 455 Kc (Ceramic Filter SFU type 455)
Local oscillator: VFO with Fine Tuning varactor diode
BFO: Ceramic Filter 455 SFU
RF PA: Power FET IRF640, IRF540, IRFZ44
DC: 13.8 V
RF Power: Over 8Watt
Description Schema.
The order of assembly sequence of assembling consecutive start BFO, VFO, AF Amp, IF amplifier and detector products to filter amplifier circuit, Mic Amplifier, Balanced modulator, RX mixer + Rf amplifier, mixer TX last order to facilitate the checking of each unit due to series This is a merger of several units of its own circuit.
BFO.
Stages 13, 12, 10, and 9 provide higher octaves, with Stages 8 to 4 being in the region of ultrasound. If the oscillator’s output is taken to the aerial of a Medium Wave Radio, L1 may serve as the search coil of a Pipe Locator, with a range of about 50 mm. This is tuned by finding a suitable heterodyne (beat note) on the medium wave band. In that case, piezo sounder Bz1 is omitted. The Simple Oscillator / Pipe Locator draws around 7mA from a 9-12 V DC source.
