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Tampilkan postingan dengan label Rangkaian Antena. Tampilkan semua postingan
Tampilkan postingan dengan label Rangkaian Antena. Tampilkan semua postingan

Rangkaian Penguat Antena VHF 30 Watt

Rangkaian Penguat Antena VHF 30 Watt
Rangkaian Penguat Antena VHF 30 Watt

30 watt amplifier schematic shown below provides an appropriate power boost with an input of 4 watt up to 6 watts. The circuit is designed to cover 88-108MHz FM Broadcast Band. However, the circuit is very stable at my place and provides a clean-output through seven (7) element Butter-worth low-pass filter. The heart of the circuit is 2SC1946A VHF RF power transistor. The transistor is specifically designed for operation in frequencies up to 175 MHz, with very good results.
As you can see, the power line is well decoupled. The amplifier current can be over 5 amps. All the coils are made from 16gauge laminated wire (or Silver copper wire can do best) and the RFC can be of HF toroid core (as shown in the picture) or 6 holes ferrite bead.C3 and R1 forms snubber circuit while R2 and C6 prevent the amplifier from self-oscillation at VHF, sometimes you need to add 180 ohms in parallel with L7.That will cause the amplifier to dissipate UNDESIRABLE VHF thereby reducing spurious level.

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Rangkaian Preamplifier Booster Antena UHF

Rangkaian Preamplifier Booster Antena UHF
Rangkaian Preamplifier Booster Antena UHF

UHF frequencies in the range 450-800MHz. It has a gain of around 10dB and is suitable for boosting weak TV signals. The MPSH10 transistor used is available from Maplin Electronics order code CR01B. Alternatives that may be used instead are BF180 and BCY90. The tuned circuit comprising the 15nH inductor and 2.2pF capacitor resonate in the centre of the UHF band. The 2.2pF capacitor may be exchanged for a 4.7pF or a trimmer capacitor of 2-6pF to improve results. The approximate frequency response is shown below. N.B. This is a simulated response using the TINA program produced by using a swept 20uV input swept over the frequency range 400-800MHz. Output was measured into a 1k source and the frequency generator has a 75ohm impedance.

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