Radio circuit diagrams electronics projects for radio transmitter, radio receiver circuit, rf amplifiers, rf boosters and some other related RF circuits like: fm antenna booster, microwave transmitter and wireless modules.
A very simple and efficiency active antenna electronic project can be designed using this electronic schematic circuit that is based on transistors. This active antenna electronic project is useful for a wide range of RF frequencies covering three RF bands HF , VHF and UHF . This simple active antenna is designed to amplify signals from 3 to 3000 MegaHertz, including three recognized ranges: 3-30Mhz high-frequency (HF) signals; 3-300Mhz veryhigh frequency (VHF) signals; 300-3000MHz ultra-high (UHF) frequency signals.
This HF VHF UHF active antenna contains only two active elements : Q1 (which is an
MFE201 N-Channel dual-gate MOSFET) and Q2 (which is an 2SC2570 NPN VHF silicon transistor). Those transistors provide the basis of two independent, switchable RF pre-amplifiers. Two DPDT switches play a major role in this circuit , switch S1 used to select one of the two pre-amplifier circuits (either HF or VHF/UHF) and switch 2 is used to turn off the power to the circuit, while coupling the incoming RF directly to the input of the receiver.
S2 is useful to give to receiver nonamplified signal access to the auxiliary antenna jack, at J1, as well as the on-board telescoping whip antenna.
This circuit must be powered from a simple 9 volt DC power circuit ( or a 9 volts battery) and is very useful for use as an indoor antenna .
A very simple antenna amplifier electronic circuit project can be designed using this circuit diagram .
This antenna amplifier electronic circuit can be used for a frequency range between 1 and 300MHz .
This circuit antenna amplifier can be used for high frequency and VHF band ( for radio and TV) and will provide a 22 dB gain . This antenna amplifier electronic project has a very low noise , under 1.6dB .
This VHF, FM amplifier circuit is constructed based on the BFT66 transistor connected in common emitter connection.
L1 coil has a 6uH value , but can be used any coil for high frequency ( with a value between 5.6 to 6.8 u H) . L2 coil is an air core type coil and it has 5-6 turns (10mm long and 5 mm diameter) . For L2 coil can be used a 0.25 mm Cuem wire . The pcb of this circuit must be placed near the antenna , in a small metallic box . This VHF antenna circuit must be powered from a 12 volts DC power supply circuit , you can use a 12 volt battery , because the current consumption of this circuit is very low under 10mA.
You can replace T1 transistor wit some other UIF similar transistor type which have a very low noise factor .
A very simple wideband amplifier circuit can be designed using the MAR-6 IC manufactured by Mini Circuits . This MAR-6 VHF-UHF wide band amplifier circuit will providing stable amplification of at least 9dB up to 2GHz, combined with a low noise figure (about 3dB).
The MAR-6 comes in a very small cylindrical package, about 2mm in diameter and 2mm high. It’s fitted with four radial leads at 90° (two of which are earthed), and is basically a two-transistor amplifier with unturned and low value loads in order to achieve the required wide bandwidth and be capable of driving a co-axial cable.
Because the MAR-6 is designed to receive its power via the signal output pin, it’s very suitable for use as a masthead amplifier. It requires about 3.5V DC, at a working current of around 16mA.
As you can see in the circuit diagram this masthead amplifier electronic project , require few external electronic parts , so if you will use SMD components you’ll have a very compact design . With power applied, the LED should glow reassuringly and you should be able to measure about 6.8 - 7V DC at the end of R1 nearer IC2 and C5 . If the LED doesn’t glow and you get no voltage reading, chances are that you’ve wired the DC input with reverse polarity .If the LED doesn’t glow but there’s almost the full plug-pack voltage present at R1, you’ve almost certainly wired the LED in backwards.