Also known as: RSP1B, SDRplay RSP1B
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SDRplay RSP1B is a low-cost, receive-only software-defined radio that tunes continuously from 1 kHz to 2 GHz with a 14-bit ADC and up to about 10 MHz of visible bandwidth.1 It is SDRplay’s refresh of the popular RSP1A, adding improved LF/MW/HF performance while keeping the same Mirics MSi001 tuner and MSi2500 sampling chip — so it offers markedly more dynamic range and preselection than an RTL-SDR in a similar price class.2
Key takeaways 14-bit, continuous 1 kHz–2 GHz, receive-only — the RSP1A refresh. The RSP1B gives you far more dynamic range and real front-end preselection than an 8-bit RTL-SDR, with a ~10 MHz span that can capture a trunked system’s control and voice channels at once, plus improved LF/MW/HF handling. GopherTrunk support is network only: it drives the RSP1B over a SoapySDR/rtl_tcp bridge, not as a direct USB device — SDRplay’s closed API/service rules out the pure-Go USB path used for RTL-SDR, HackRF, and Airspy. Around $130. Like every receiver, it can’t decode AES encryption.
GopherTrunk support: network only. GopherTrunk drives the RSP1B over the network via SoapySDRServer/SoapyRemote (or an
rtl_tcp-style bridge), not as a direct USB device — you run SDRplay’s API service and a SoapySDR server on the machine it’s plugged into and mount it over TCP. GopherTrunk’s pure-Go USB drivers cover only RTL-SDR, HackRF, and Airspy. See the hardware guide and rtl_tcp notes.
Overview
The RSP1B is SDRplay’s current entry-level model, replacing the RSP1A at the base of the RSP line. Its appeal for scanning and general monitoring is the same combination that made the RSP1A popular: an uninterrupted tuning range — no LF/HF/VHF gap — with real front-end filtering, a bank of switchable preselection filters, an MW/broadcast-FM notch, and a software-controlled bias tee for powering an active antenna or LNA. Sampling at 14 bits gives it far better dynamic range and resistance to intermodulation than the 8-bit RTL-SDR, and the RSP1B’s refreshed design tightens up performance at the low end of the spectrum specifically.
What it is
Internally the RSP1B is a Mirics chipset: the MSi001 is a broadband
zero-IF tuner, and the MSi2500 handles the ADC and USB interface. The
device streams raw IQ samples over USB 2.0; all channelisation,
demodulation, and decoding happen on the host. The maximum
displayed spectrum span is around 10 MHz, though the ADC actually samples faster and
decimates internally. Like the rest of the RSP family it is not libusb-generic — SDRplay
ships a closed API/service that applications talk to, and a
SoapySDR module (SoapySDRPlay) that exposes the RSP through the
common Soapy interface used by GNU Radio,
SDRangel, CubicSDR, and others.
Variants
The RSP1B sits at the base of a family that trades up in front-end sophistication:
- RSP1A — the model the RSP1B refreshes; still widely sold and functionally very close.
- RSPdx — adds more preselection filters, three antenna ports, and a high-dynamic-range (HDR) mode optimised for LF/MW/HF.
- RSPduo — a dual-tuner design that can run two 2 MHz streams at once for diversity or simultaneous monitoring of separated bands.
All share the same underlying Mirics silicon and the same SDRplay API, so software support carries across the range.
Relevance to SDR
The RSP1B is a strong general-purpose receiver for HF through UHF: shortwave and amateur bands, ADS-B at 1090 MHz, VHF/UHF land-mobile, and broadcast monitoring. Its 14-bit converter and preselector make it a real step up for crowded RF environments where an RTL-SDR would overload.
For trunking specifically, the ~10 MHz span lets it cover a system’s control and voice channels from a single capture, much like an Airspy. The practical caveat is the driver model: GopherTrunk drives RTL-SDR, HackRF, and Airspy hardware directly, whereas the RSP line depends on SDRplay’s proprietary API/service. Using an RSP1B with GopherTrunk therefore hinges on a SoapySDR/RSP bridge rather than a native backend — check the project status before assuming turn-key support. As a receiver the hardware is well suited to the task; the integration path, not the RF, is the limiting factor.
Where to buy
The RSP1B is sold by SDRplay and its distributors, and listed on Amazon — though stock is often third-party, so the button is a tagged search that resolves to current listings. Before you buy it for GopherTrunk, remember the integration path: it is supported over the network only, through a SoapySDR/rtl_tcp bridge rather than GopherTrunk’s direct USB drivers — see the hardware guide. If you want a plug-and-play device, a RTL-SDR or Airspy is the simpler pick; if you already run an RSP1A, the RSP1B is a marginal upgrade rather than a must-have.
As an Amazon Associate, GopherTrunk earns from qualifying purchases — at no extra cost to you. It never changes what we recommend.
Sources
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Software-defined radio — Wikipedia, background on receiver-class SDRs including the SDRplay RSP line. ↩
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RSP1B — SDRplay, official product page with tuning range, 14-bit ADC, filtering, bias-tee, and the RSP1A-to-RSP1B improvements. ↩
Frequently asked questions
Does GopherTrunk support the SDRplay RSP1B?
Yes, but network only — exactly like the RSP1A. GopherTrunk’s pure-Go USB drivers cover RTL-SDR, HackRF, and Airspy, not the RSP’s closed API/service. You run SDRplay’s service and a SoapySDR server (or an rtl_tcp-style bridge) on the machine the RSP1B is plugged into, then mount it over TCP. See the hardware guide.
What's the difference between the RSP1B and the RSP1A?
They’re closely related single-tuner 14-bit receivers. The RSP1B refreshes the RSP1A with improved LF/MW/HF performance (better handling of strong broadcast signals in those bands) and stays otherwise similar — same 1 kHz–2 GHz range, same ~10 MHz span, same SDRplay API. Either is a fine 14-bit step up from an RTL-SDR.
Is the RSP1B a good SDR for scanning trunked systems?
As RF hardware, yes — its 14-bit ADC, continuous 1 kHz–2 GHz coverage, and front-end preselection give it far more dynamic range than an 8-bit RTL-SDR, and its ~10 MHz span can cover a system’s control and voice channels in one capture. The caveat is the integration path: it runs over a network bridge, not as a plug-and-play USB device.
RSP1B or an RTL-SDR / Airspy for GopherTrunk?
If you want the simplest setup, a directly-supported RTL-SDR or Airspy plugs in and works with no bridge. Choose the RSP1B when you specifically want its 14-bit dynamic range and continuous HF-through-UHF coverage and don’t mind running a SoapySDR server for it. And no SDR of any resolution decodes AES encryption.