For demanding FM DX'er ... (18 bits ADC SDR)

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Patrick73
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For demanding FM DX'er ... (18 bits ADC SDR)

Post by Patrick73 » 22 Feb 2017 15:40

Patrick
Main interests : NDB, MW & FM DX'ing
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pe1etr
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Re: For demanding FM DX'er ... (18 bits ADC SDR)

Post by pe1etr » 22 Feb 2017 18:20

The final bandwidth of 600 kHz might be a problem for many FMDXers, especially as the alternatives have several MHz bandwidth.

Peter Blackpool UK

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Patrick73
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Re: For demanding FM DX'er ... (18 bits ADC SDR)

Post by Patrick73 » 22 Feb 2017 19:00

This is indeed a downside ... But I rarely use more than 1.5 MHz BW.
Regarding this new SDR, I don't understand if the maximum BW is 600 kHz in any case, or if it's the final bandwidth after decimation ...
Patrick
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pe1etr
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Re: For demanding FM DX'er ... (18 bits ADC SDR)

Post by pe1etr » 22 Feb 2017 19:28

Patrick73 wrote:
22 Feb 2017 19:00
This is indeed a downside ... But I rarely use more than 1.5 MHz BW.
Regarding this new SDR, I don't understand if the maximum BW is 600 kHz in any case, or if it's the final bandwidth after decimation ...
Yes, the 600 kHz is after decimation. There doesn't seem to be an option to use the HF+ with less decimation or no decimation, like there is for Airspy.

Peter

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Re: For demanding FM DX'er ... (18 bits ADC SDR)

Post by Tim Bucknall » 02 Dec 2017 13:28

No driver required? Heard that one before :D
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Re: For demanding FM DX'er ... (18 bits ADC SDR)

Post by satnipper » 02 Dec 2017 14:48

No drivers required for the Funcube dongle. No reason to doubt what they say.

daveB
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Re: For demanding FM DX'er ... (18 bits ADC SDR)

Post by daveB » 03 Dec 2017 00:04

It is a trade off between ADC resolution and bandwidth. SDRPlay RSP1A now offers 14-bits resolution at sample rates of 6 MHz and below - which I guess would give an effective bandwidth of 5 MHz. In theory that should give an extra 12 dB dynamic range compared to the 12 bits of the Airspy/Airspy Mini/SDRPlay RSP1/RSP2.

The only SDR that offers 16 bit ADC with a wide (6MHz) bandwidth that I can see at a reasonable price is the Elad at around £500. The Airspy HF is going to be around £200 after you've paid VAT on it.

I find the SDRPlay and Airpsy Mini more than acceptable with 12 bit ADC for my location but they can be overloaded if you take the gain a bit high.

So your choices are:

RTL dongle - 8 bit ADC - cheap! (VHF/UHF/SHF)
Airspy Mini (VHF/UHF/SHF) - 12 bit dongle - 6MHz sample rate - but you can push it to 10 MHz - £120
Airspy (VHF/UHF/SHF) - 12 bit - 10 MHz sample rate - £210
SDRPlay RSP1A (VLF-SHF) - 14 bit ADC 6 MHz sample rate or 12 bit ADC at 8 MHz sample rate £91 (SDRPlay)
Airspy HF (HF/VHF) - 16/18 bit ADC - 600 kHz bandwidth - £229 (Moonraker)
Elad FDM2 (HF/VHF)- 16 bit ADC - 6 MHz sample rate - £460

The RSP1A is tempting if only for it's much improved filtering and gain distribution despite the better dynamic range offered by the Airspy HF.
SDRPlay, AirSpyMini, RTL dongles, SB920s, Yamaha TX930. 5 ele compact yagi on rotator at 18ft agl. FM5 facing east, FM5 facing south, FM3 facing NE, OIRT dipole, 3-ele Moxon vertical facing east.

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