Архив за Июнь, 2019

Other SDR Devices • Re: New Scanning and Spectrum Analyser software for SDRplay RSP family

Approximately how many frequencies can this software scan per second ?

I'm trying to decide whether to spend my money on this, or a dedicated base station receiver.

I am frustrated by the slow scanning speed of SDSharp with the Frequency Manager Suite.

Statistics: Posted by CharliePrime — Sun Jun 30, 2019 10:41 pm

Other SDR Devices • Re: MSi.SDR sound crackle pulses and spurs

Hm... your PCB has different layout than my one... It seems that they are different versions...

Can you show the photo of back side? Do you have marking on the flash memory chip?

Here is my:

Statistics: Posted by radiolistener — Sun Jun 30, 2019 9:34 pm

First attempt at HRPT

First attempt at HRPT submitted by /u/amdorj
[link] [comments]

What is the best SDR software for an old Intel Atom laptop?

I have an old Toshiba NB100 laptop with an Intel Atom as CPU. What is the best lightweight SDR software for this laptop?

OS: Ubunut 14.04 LTS

Memory: 2,0 GiB

CPU: Intel Atom @ 1.60 GHz x 2 cores

GPU: Intel 945GME x86

32 bit

I don't think there's much hope for it left but you can never know.

submitted by /u/melvin2204
[link] [comments]

Da couple of doubts about parabolic dish + homemade helical feed

Hello everybody!

A couple of weeks ago, I was totally new to this hobby. Since then, I have been able to get good NOAA APT images with my double cross antenna and now I want to try something different.

I live in Europe, so there is no HRIT possibility for me as of now (maybe Elektro-L N3 in a near future?). Then, I would like to get some HRPT pictures from NOAA and Meteor M2 satellites (I have not seen enought information about how to get HRPT from Meteop). For that, I am planning to build an antenna tunned for 1,7GHz, which is based on a parabolic dish with an helical feed. My questions now are:

  1. Is the directivity of the global antenna determined by the number of turns of the fees or only by the dish itself?

  2. Can small (120-80cm) dishes perform well at these frequencies?

  3. What length should the feed be? What is the maximum recommended length? I originally made a 7 turn feed with λ/4 spacing, but it is 30cm long and I dont know wether it would perform well (I have a 80cm dish). In case it wouldn't, should I reduce the number of turns or try different spacings like λ/8?

  4. Is it feasible/difficult to obtaing good imagea by hand-tracking the satellite?

  5. Is it highly recommended to build a bandpass filter? If so, for these frequencies, would you recommend me to design an electronic filter or try to build a hairpin or cavity filter? If it were possible to obtain good images without a filter, should I then use a LNA?

I know these are a lot of questions, so thank you in advantage for the help!

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

Other SDR Devices • Re: MSi.SDR sound crackle pulses and spurs

More testing, when (hdsdr) 10Mhz sample rate and tune to 24Mhz (same occurs other frequencies, but worst on xtal and harmonics) then slow and huge oscillation occurs. If tuning one herz up or down and oscillation change, interference is audible on AM too. Also when put finger over input filters or terminate input oscillation change. The spur "bump" also goes around.
I think if whole system oscillates, due to pcb design or is something to bad 24Mhz leak and maybe these affect vco? Voltage at regulator seems to be steady. At 8Mhz sample rate same occurs but much less, spur bump also goes around.

Statistics: Posted by artm — Sun Jun 30, 2019 12:51 pm

Troubleshooting Help • Strange Display SDRSharp

Been using V3 SDR for NOAA images and have been getting some pretty good images with my v-dipole antenna. Bought an LNA and placed in line near antenna and of course, my image quality has gone to the toilet. Seeing strange clipping on left and do not know if it is normal. Since I have the V3 and using software to turn on the BiasT it does not seem to make a difference in image quality.

Ant - LNA In- LNA Out - RTL SDR (not using external power for LNA since I have an V3 SDR). I also tried an FM blocker connected to the SDR and SDRSharp image looks the dame.

Not sure what is happening here.

Statistics: Posted by njrusty — Sun Jun 30, 2019 12:34 pm

Off-Topic • Re: More fake units sold on Ebay

I bought from trademe.co.nz a device reputed to be an RTL-SDR v3 which differs in a number of respects from the pictures shown on the RTL-SDR.com Blog sales sites on Aliexpress and eBay.

The most obvious differences are that it has an electrolytic capacitor adjacent to the "TCXO"" and that the date on the bottom left corner of the board is "2018 4 18" rather than 2016. The sticker on the case shows NSY 2018 8

Is this a counterfeit or a revision?

Statistics: Posted by drb — Sun Jun 30, 2019 11:59 am

Other SDR Devices • Re: MSi.SDR sound crackle pulses and spurs

I got SDRuno so i did some experiments with it. At 10Mhz after adjusting IF gain noise floor jumps s1 to s7 slowly for some time and then stabilize. Does somehow high noise affect chip AGC? although AGC was off. The noise on display was the flat, no drops at edges until gain is down, when hopping nott occur. Lower sample rates edges was normal. I didn't see crackles but sometimes noise was rought and noise floor bouncing a few dB's. When using low-IF everythin was better. This roughness was on hdsdr too.

Also with sdruno sometimes tuning causes some spikes all over display, these was not seen with hdsdr.

Interesting, in your dongle component markings are scratced off, mine not except one. No electrolyte neither but seems not necessary.

Statistics: Posted by artm — Sun Jun 30, 2019 11:11 am

Troubleshooting Help • Re: Has anyone managed to get a Raspberry Pi 4 working with an RTL SDR?

Does the lack of replies mean that nobody else has tried or nobody else has had problems?
Essex Radar

Statistics: Posted by Feek — Sun Jun 30, 2019 6:30 am

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