Архив за 01.03.2019

Comment on Using Two PlutoSDR’s for Full Duplex Packet Radio Communications by Corrosive of SignalsEverywhere

No problem, thank you!

I wouldn’t make these videos if you guys didn’t watch them.

Баги конвертера NooElec, кто пользуется, подтвердите или предположите причину…






Баги конвертера NooElec, кто пользуется, подтвердите или предположите причину происходящего

Рисунок 1 - Так работает НЕСДР+ конвертор при откл питания конвертора т.е. ничего лишнего нет.
Рисунок 2 - Включаем конвертер - Что за неприятность, в виде модулированного горба?
Рисунок 3 - Тот же горб при макс усилении.
Появляется «зеркалка опорника», что правильно, но горб?
На сайте производителя о наличие горба ничего нет.
Рисунок 4 - Непонятные трыки при прогреве конвертора .
Тут амплитуда всплесков невелика и повторяются раз в 50 сек.

Грешил на неявные помехи от ПК.
Сегодня специально запитал конвертор от батареек – ничего не изменилось.
Ваше мнение?????

Рисунок 5 - Пока писал, прошло минут 7, конвертор остыл вот, что после включения

Comment on Using Two PlutoSDR’s for Full Duplex Packet Radio Communications by Mehdi

Thanks for the video and clarification

Comment on Using Two PlutoSDR’s for Full Duplex Packet Radio Communications by Corrosive of SignalsEverywhere

I didn’t say a single PlutoSDR is half duplex, but you need two if you’re going to run full duplex between them and the software I was using was only half duplex.

I’m very well aware the Pluto is full duplex, it’s the only reason I made the above video.
If somehow I did say that, I misspoke

Comment on Using Two PlutoSDR’s for Full Duplex Packet Radio Communications by Corrosive of SignalsEverywhere

Can you provide some detail on how you’re making the network connection with the computer and pluto sdrs?
Those speeds are amazing compared to traditional 1200 and even 9600 baud can do. It’s exactly what i’ve been wanting to do for some time now.

Different NOAA reception of QFH in contrast to V-dipole? (and something else)

Different NOAA reception of QFH in contrast to V-dipole? (and something else)

So, I'm running two SDRs.

SDR-RTL blog dongle to a V-dipole and a NooElec NESDR Mini 2 paired with a SPF5189Z LNA to a QFH.

I recorded both receptions simultaneously at 137.1 MHz, I used Gqrx for the V-dipole and CubicSDR for the QFH. After changing the sample rate in Audacity to 11025 Hz, wxtoimg returned the following pictures.

V-dipole

QFH

What's the possible reason for the pictures being so different?

I also noticed that when I touch the QFH, the NOAA signal improves notably when the rest of peripheral broadcasts disappear or turn to noise. Am I just improving the signal by turning my body into an antenna or could it be a case of impedance matching?

submitted by /u/Thantri
[link] [comments]

Comment on RTL-SDR Tutorial: Decoding Inmarsat STD-C EGC Messages by Robby

Thanks guys.. to I have had no luck. Fustrated beyond and means. I build a (Adam)patch and modified a GPS antenna ..bought a version 3 rtl_sdr dongle. Have a nooelec filter but no go…is the QUAL value suppose you get to 100 or just over 0… Tried everything.. maybe I can’t get inmarsat in South Africa but I see a lot of peaks

The cheapest NOAA antenna I could make and the image I got from it

As a challenge, I decided to make the cheapest NOAA setup I possibly could. The only things I bought specifically for this project was a cheap SDR just to see how a low-end model would perform, and a short piece of SMA coax that I cut the end off to make the lead for the antenna. Everything else I already had laying around from other projects or I got from friends.

Part of the reason I did this was just as a challenge, but the other reason is because I mentor on a local robotics team and the head of the team is interested in maybe having the students build NOAA antennas as a project during the off-season and take the antennas (and SDRs) home with them after they've built and tested them, so we're trying to get cost down per student. In total, I paid around $28.

Behold, budget satcom: https://imgur.com/gallery/DLUh340

submitted by /u/DuckEsquire
[link] [comments]

RTL-SDR Discussion • Re: Problem with FC0012 Tuner & librtlsdr0

I'm seeing it in 2019 under Raspbian with librtlsdr-dev (0.5.3-11) and librtlsdr0 (0.5.3-11) installed. But I also have rtl-sdr from git August 2018. It's a mismatch of versions, but the dates on the executables match the git date. I wanted librtlsdr especially because I'm writing a program using it.

I took out the git version executables which were in /usr/local/bin and now I don't get that error anymore. The version of rtl_fm from the debs is in /usr/bin

I'm trying to decode Lojack signals with multimon like
rtl_fm -M fm -p 59 -f 173075000 - | multimon -v 10 -t raw -a AFSK1200
but it's still not working

Statistics: Posted by ab1jx — Fri Mar 01, 2019 7:22 pm


Troubleshooting Help • matlab & simulink book

I am working my way through a book (see attachment frontcover) and have come across a model of a receiver in SIMULINK - see second attachment. In this model you will see an RF gain of 50 dB and another gain (MHz) of 1e6 ?

Is this related to gain bandwidth product i.e. the gain of the receiver is constant at 50 dB upto 1 MHz ?
receiver.png

frontcover.png

Statistics: Posted by dericko — Fri Mar 01, 2019 5:33 pm


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