Internal gain vs external amplifier

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Remon
Posts: 47
Joined: Fri Jun 22, 2018 2:49 am

Internal gain vs external amplifier

Post by Remon » Tue Aug 28, 2018 3:36 pm

Is it worth buying a Jim M75 amplifier or will I get similar results with the internal gain?

rtlsdrblog
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Joined: Mon Nov 19, 2012 11:54 pm

Re: Internal gain vs external amplifier

Post by rtlsdrblog » Wed Aug 29, 2018 4:53 am

An external amplifier is usually better, because if you get it close to the antenna you will overcome losses in the coax cable and any connectors. If it's a low noise a amplifier you also see an improvement from reducing the noise figure.

Of course it's all up to your system setup, and RF environment as to whether or not you'll see an improvement. Remember that LNAs can make things worse if they overload or have too much gain that causes your RTL-SDR to overload.

The amp you show is quite expensive, but has three filters built in which may be useful to you. Otherwise just by a cheap SPF5189Z LNA (we have one in our store now), or an LNA4ALL.

w5dxp
Posts: 26
Joined: Sat Apr 14, 2018 9:05 pm

Re: Internal gain vs external amplifier

Post by w5dxp » Wed Aug 29, 2018 12:34 pm

For those of us (hams), more interested in HF (3-30 MHz), an up-converter is preferred to an amp.

Username
Posts: 508
Joined: Sun Oct 09, 2016 7:27 am

Re: Internal gain vs external amplifier

Post by Username » Mon Sep 03, 2018 2:13 pm

I use there Amps and Filter the are quite good: http://stores.ebay.com/gpiolabs/ :D

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