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Old 20th Oct 2018, 7:26 pm   #1
Bazz4CQJ's Avatar
Join Date: Apr 2009
Location: Oxfordshire, UK.
Posts: 2,766
Default 0.1-2000 MHz Wide Band Amplifier ~4

I'm posting this in "homebrew" not because I made it, but because of what it might be useful for incorporating in to other projects.

I stumbled across a Youtube video recently where some geezer said that he needed an amplifier to go in front of his $8 digital frequency counter and so he had bought an $8 wideband amplifier! A look on ebay found numerous suppliers of these units (see attached) and two of them arrived in the mail today, costing just over 4 each. This is the blurb;

0.1-2000MHz RF Wide Band Amplifier Features
-This product with wide frequency range, high gain, low noise figure
-This product can be applied to various rf receive front-end and increases communication distance
-Used for Short wave, FM radio, remote control receiver, such as cable TV signal amplifier need low noise rf signal amplification
Diameter of end: 5mm
Color:green + gold
Operating frequency:0.1-2000MHz
Amplifier gain:
F=0.1MHz, gain=32dB
F=500Mhz, gain=31dB
F=1000MHz, gain=29dB
F=1500Mhz, gain=25dB
F=2000MHz, gain=20dB
Maximum power output:+10dBm (10mW)
Power supply voltage: 6-12 VDC
System impedance:50Ω, SMA connectors.
1.When working frequency is less than 500 MHz it get well gain flatness, can make it less than 1dB after careful adjustment. The lower frequency the higher gain consistency.
2.Amplifier working frequency of the lower limit is subject to input and output capacitor, the default value is 0.1 uF, working to 0.1 MHz. Increase the input and output capacitance appropriately, can extend the cut-off frequency, such as 10uF capacitance can work to 5KHz.
3.When the power supply voltage changes in 5-8 v, it can be used as a variable gain amplifier, gain increases with the increase of the power supply voltage, which suitable for radio frequency receive front-end circuit, using DA control power supply voltage, to control the gain of the amplifier, automatic gain control
4.When the power supply voltage in the 8-10 v, the low frequency end gain up to 30 db, at this time the amplifier has a low noise coefficient and good stability.
5.When the voltage is 12 v, reach maximum gain, the low frequency end gain of 32.5 dB.

Has anyone bought one of these previously? My first use is similarly for a DFC, for which it really needs a FET buffer in front of it, and a maybe a Schmidt trigger at the back of it? Might do well in front of a VHF tuner or DAB radio for someone who is struggling?

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Data beats opinions most times... that's my opinion, though I have no data on that.

Last edited by Bazz4CQJ; 20th Oct 2018 at 7:34 pm.
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