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====== Low-noise amplifier LNA01A ======

A low-noise preamplifier module ([[http://en.wikipedia.org/wiki/Low-noise_amplifier|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 [[http://www.avagotech.com/pages/en/rf_microwave/transistors/fet/atf-53189/|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 tin shielding can__.

The following scheme shows the connecting of the module: [[http://www.mlab.cz/WebSVN/filedetails.php?repname=MLAB&path=%2FModules%2FCommRF%2FLNA01A%2FSCH%2FLNA.pdf| LNA01A scheme]].

===== Tuning =====

The amplifier tuned to 143MHz band:

{{:cs:lna01a_assembled.jpg?direct&200|Assembled preamplifier LNA01A without the shielding can.}}

{{:cs:lna01a_measuring_setup.jpg?direct&200|Arrangement for measuring.}}

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.

{{:cs:lna01a_transmission_curve.jpg?direct&200|LNA01A transmission curve}}

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 [[en:sdrx|SDRX01B]]. Its characteristics are optimized for use in radioastronomy or cosmic research.

===== Covering =====

The module fits into __metallic tin shielding can__ [[http://www.gme.cz/plechove-krabicky-stinici-cinovane/u-ah101-p622-024/|U-AH101]]

== References ==
  * [[http://www.ha8et.hu/PDF/EXTRA-2%20144%20MHz%20Contest%20Preamplifier.pdf|Extra-2]] - the original HA8ET construction

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