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Table of Contents
Low-noise amplifier LNA01A
A low-noise preamplifier module (LNA). The original construction is intended to be used in bands around 143MHz, but it is probable, that it can be used in other bands as well, as the used transistor ATF-53189 shows good characteristics up to approximately 6GHz.
Construction
The connection of the amplifier is implemented using the FR4 PCB. It is possible to fit the PCB with straight SMA connectors or edge connectors. The amplifier is expected to be placed inside the metallic shielding box.
The following scheme shows the circuit of the module: LNA01A scheme.
Tuning
The amplifier tuned to 143MHz band:
The transmission curve of the LNA01A. Smaller horizontal lines in the upper part of the screen have a scale increment of 10MHz, increment for larger lines is 100MHz and 200MHz. The gain is approximately 27 dB.
A coil performing on 144Mhz has 7 turns of 0.5mm wire around a rod with a diameter of 4mm (a drill). The coil is ..?
Cívka na 144MHz vychází 7závitů z drátu 0,5mm motáno na průměr tyčky 4mm (vrták). Cívka je roztažená tak jek je vidět na fotce C1 a C2 je 8,2pF. Zpětná vazba u LNA není vyhodil jsem ji není tam potřeba, domnívám se že zvyšuje šumové číslo a snižuje zisk asi o 1dB. Trim tam taky nedávám je tam odpor 45 Ohm a celkový proud celým LNA by měl být kolem 153mA, potom je proud kolektorem asi 135mA.
The measured parameters
Applications
This preamplifier is primarily constructed for use in combination with SDR receiver SDRX01B. Its characteristics are optimized for use in radioastronomy or cosmic research.
Covering
The module fits into metallic tin shielding can U-AH101
References
- Extra-2 - the original HA8ET construction