Re: #aero Jaero too low signal strength #aero

Tomasz Lemiech
 



On Tue, Jan 15, 2019 at 8:59 PM Roland Fechter <fly-fechter@...> wrote:


please see enclosed snap - only decoding I achieved - allĀ  other main freqs inaccessable due to low dB- max 4db)

What are "other main freqs"? From which satellite? At what frequency?

18 dB is way above of what's required for a successful decode of 600 and 1200 bps channels. 4 dB is a little low indeed.

What I see on your screenshot is that your waterfall is all-red, which either means your contrast setting in SDRSharp is wrong or your receiver gain is way too high or your NooElec LNA is saturated (too high signal on input). Just to make sure: are you using this one: https://www.passion-radio.com/sdr-accessory/lna-outernet-467.html ? This amplifier has two stages and a bandpass filter which is placed in between the stages. The input side is not filtered, so the device may easily get saturated with in-band or out-of-band signals (like TV or FM radio) when attached to a high-gain or wideband antenna. I'm using this amplifier with a DIY patch antenna, which is inherently narrowband, so it acts like a bandpass filter. Despite it having only about 8 dBi of gain, it's enough to receive 600, 1200 and 10500 channels from Alphasat (I'm in central Poland and I have this sat at about 30 deg of elevation). Here are a few pictures and screenshots for you to compare: https://szpajd.ernet.info/~szpajder/inmarsat/DIY_patch/

Also try disabling AGC in the left pane in SDRSharp. Just for a quick test.

Cheers,

--
Tomasz Lemiech

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