Search found 53 matches

by qrp
Fri Nov 06, 2020 4:49 pm
Forum: RTL-SDR Discussion
Topic: Hard Question: Is it worth all the headaches?
Replies: 6
Views: 1025

Re: Hard Question: Is it worth all the headaches?

UncleVinny wrote:
Mon Oct 26, 2020 1:53 pm
What we NEED is a program that self-installs and walks you through the process.
We need standards, instructions that work, a guide book, timely feedback from professionals.
all instructions are present on internet. There are a tons of instructions.
by qrp
Fri Nov 06, 2020 1:21 am
Forum: RTL-SDR Discussion
Topic: To near to the RF source?
Replies: 4
Views: 920

Re: To near to the RF source?

How can I test the dongle? you can test it with HDSDR and signal generator, for example FY6800 or PSG9800 1) Start HDSDR 2) Select Bandwidth = 2400000 Hz 3) Open Options => Calibration settings 4) Select S-meter Calibration tab and press Reset button to reset S-meter calibration to default 5) close...
by qrp
Sat Oct 10, 2020 11:42 pm
Forum: RTL-SDR Discussion
Topic: Direct sampling to bandwidth output, how done?
Replies: 10
Views: 2289

Re: Direct sampling to bandwidth output, how done?

And some signals are wide-band, but are still partially usable without hardware RF front-end anti-alias filtering. For instance plenty of people use RTL-SDR v.3's in direct sampling mode, and those devices do not anti-alias out signals above and/or below 14.4 MHz. But the RTL2832 still does later a...
by qrp
Fri Oct 09, 2020 9:30 pm
Forum: RTL-SDR Discussion
Topic: Direct sampling to bandwidth output, how done?
Replies: 10
Views: 2289

Re: Direct sampling to bandwidth output, how done?

Sorry. That's incorrect. Maybe you didn't read the fine print in your textbooks. Sorry, but you're wrong. You can found some of my software for SDR receivers, transceivers and vector network analyzers, include firmware and apps here, on rtl-sdr site and on github. I'm told you that thing not becaus...
by qrp
Wed Oct 07, 2020 4:08 am
Forum: Other SDR Devices
Topic: Dragonfly RX-666
Replies: 3
Views: 1761

Re: Dragonfly RX-666

There is no FPGA, so it cannot perform digital down sampling. So, it requires to get full ADC bandwidth stream on PC, it needs very high performance PC in order to process such stream. Also it uses usual Chinese TCXO oscillator (like ROJON) which phase noise is not good enough for 16-bit ADC (it req...
by qrp
Wed Oct 07, 2020 3:41 am
Forum: RTL-SDR Discussion
Topic: Direct sampling to bandwidth output, how done?
Replies: 10
Views: 2289

Re: Direct sampling to bandwidth output, how done?

If you decimate in software, and the sampled signal has a bandwidth higher than the new target sample rate, then it is required to do anti-alias filtering in software. Thus software filtering has to be possible (DSP IIR or FIR typically). Antialias filter can be done IN ANALOG ONLY. It cannot be do...
by qrp
Wed Oct 07, 2020 3:18 am
Forum: RTL-SDR Discussion
Topic: ExtIO_RTLSDR_u8.dll with HDSDR 2.76 + dongle
Replies: 16
Views: 10427

Re: ExtIO_RTLSDR_u8.dll with HDSDR 2.76 + dongle

I am noticing that it looks like the noise floor has moved up almost 30db compared to normal levels using the RTL2832 extio. Noise floor is exactly the same. The difference is because this extio uses 32 bit sample format instead of 8 bit which is used in standard extio. Since it uses different samp...
by qrp
Tue Sep 01, 2020 10:10 pm
Forum: RTL-SDR Discussion
Topic: Direct sampling to bandwidth output, how done?
Replies: 10
Views: 2289

Re: Direct sampling to bandwidth output, how done?

Anti-alias filtering can be implemented in software or hardware by many different methods Anti-alias filtering can be done in hardware only for analog signal (before ADC). This is impossible in software (in digital domain after ADC output). The only way is to apply anti-alias filter to the analog s...
by qrp
Sun Feb 23, 2020 1:34 pm
Forum: Other SDR Devices
Topic: Automatic notch-filter for SDR# ?
Replies: 2
Views: 4872

Re: Automatic notch-filter for SDR# ?

use HDSDR, it already has automatic notch filter