HFU HF Underground
Technical Topics => SDR - Software Defined Radio => Topic started by: Tony on July 07, 2016, 1555 UTC
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I have had bad experiences with SDRPlay but I see that many people are happy with it. What am I doing wrong?
I have also an SDR-IQ and I've never had these problems.
SDRPlay is full of ghosts signals for me. I use mostly in HF SDRPlay but this is full of ghosts signals and probable intermodulation.
Antennas are Yaguis and dipoles and I've used for years without problems. This same antennas with SDR-IQ have had no problems with ghosts or intermadulacion.
Casual listeners in VHF / UHF show a more acceptable performance. Antenna was a Discone.
I´m losing some adjustment in SDRPlay to improve the work in HF ?
Thanks in advance.
Tony
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Hi, it may just be overload that could be remedied with some attenuation or some filtration.
A tuner between the antenna and sdr might help the sdrplay. The sdriq is more capable on hf by design, the sdrplay isn't hf/good antenna friendly as far as I know, it's a sdr dongle designed for v/uhf use.
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I have had bad experiences with SDRPlay but I see that many people are happy with it. What am I doing wrong?
I have also an SDR-IQ and I've never had these problems.
SDRPlay is full of ghosts signals for me. I use mostly in HF SDRPlay but this is full of ghosts signals and probable intermodulation.
Antennas are Yaguis and dipoles and I've used for years without problems. This same antennas with SDR-IQ have had no problems with ghosts or intermadulacion.
Casual listeners in VHF / UHF show a more acceptable performance. Antenna was a Discone.
I´m losing some adjustment in SDRPlay to improve the work in HF ?
Thanks in advance.
Tony
i generally find lowering the RF gain in small increments until the issue of images and inter-modulation from nearby strong signals is resolved.
i find the SDRplay has a great RF front end being extremely sensitive with a great signal to noise ratio but the downplay is the front end being overloaded by nearby strong signals within 1Mhz of the same band.
if you are using "SDR Console" on the SDRplay, you may find better results by adjusting the VFO to be about 20Khz from the center for HF.
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Hi, it may just be overload that could be remedied with some attenuation or some filtration.
A tuner between the antenna and sdr might help the sdrplay. The sdriq is more capable on hf by design, the sdrplay isn't hf/good antenna friendly as far as I know, it's a sdr dongle designed for v/uhf use.
Is that accurate? It's not being marketed as only good for V/UHF, they specifically say its range is from 10 kHz to 2 GHz, or VLF to UHF.
Also, is dongle the right word? I'm under the impression that there's more to an SDR than that, but then again I'm not well versed in this vocabulary. Are all SDR's dongles?
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Generally, "dongle" means an SDR that is (or is based on) the RTL USB TV tuner that is turned into an SDR with appropriate software. It is important to remember that these were designed for people to receive local TV stations - that's it. They have an 8 bit A/D, and very limited filtering. You can do amazing things with them for the price ($15 or so) but they cannot compare to a piece of hardware designed to be an SDR.
The SDR play does not use the same ICs as the RTL dongles. It uses a 12 bit A/D, but my understanding is the particular A/D used has an ENOB (effective number of bits) of 10.4 bits. It also does not have the same level of bandpass filtering as higher end SDR. So it is going to be "better" than an RTL dongle, but (in general) not as good as an SDR with 14 or 16 bits (which also cost more). My guess is the lack of sufficient bandpass filters is what causes the ghost signals, through intermod, etc. You can correct for this to some degree by putting an antenna tuner or preselector in front of it (between it and the antenna). Adjusting the gain, or even putting some attenuation in front of it may also help.
The dynamic range on MW/HF is huge. I have a semi local MW station that is S9+60. I also listen to stations on my netSDR that barely register S1. You need good front end filtering to make that possible, as well as a sufficient dynamic range in your A/D.