SDRplay RSP1A on Windows: device starts but zero messages decoded (SDRangel works fine with same hardware)

[miguelmoraleda]

Hello,

Environment

• AIS-catcher: v0.66 (build Mar 25 2026) — Windows x64 SDRPLAY build
• Also tried: Edge build — same result
• Device: SDRplay RSP1A
• OS: Windows 11 (10.0.26200.8039)
• SDRplay API: Updated to API 3.15 during troubleshooting — no change.
• SDRangel: 7.22.6 — decodes AIS messages immediately with the same RSP1A and antenna

Problem

AIS-catcher detects the RSP1A and appears to start streaming without errors, but receives zero messages regardless of settings. SDRangel decodes dozens of vessels instantly with the same hardware — so the antenna, SDR, and drivers are all working.

What I've tried

Gain settings (all produce 0 messages)

AIS-catcher.exe -gs LNASTATE 0 GRDB 32 -v 10 -N 8100
AIS-catcher.exe -gs LNASTATE 0 GRDB 40 -v 10 -N 8100
AIS-catcher.exe -gs LNASTATE 0 GRDB 50 -v 10 -N 8100
AIS-catcher.exe -gs agc on -v 10 -N 8100
AIS-catcher.exe -gs agc on -p 0 -v 10 -N 8100
AIS-catcher.exe -v 10 -N 8100  (defaults only)

Sample rates

AIS-catcher.exe -gs agc on -s 2304K -v 10 -N 8100   → 0 messages
AIS-catcher.exe -gs agc on -s 2000K -v 10 -N 8100   → 0 messages (upsampled to 3072K)
AIS-catcher.exe -gs agc on -s 1536K -v 10 -N 8100   → "SDRPLAY: cannot start device - sdrplay_api_Fail"

Other attempts

• Restarted SDRplay API service (via RestartService.bat) multiple times
• Updated SDRplay API to v3.15 — no change
• Tried both v0.66 and an older release — same result

Typical output (same every time)

AIS-catcher (build Mar 25 2026) v0.66-0-gbf778a29
sample rate 2304K upsampled to 3072K.
HTML Server running at port 8100
Device    : RSP1A
Settings  : rate 2304K format CF32 agc ON lnastate 0 grdb 32 ANTENNA A
Model #0-0 -> (Src: 1, Grp: 1): [AIS engine v0.66] ps_ema ON afc_wide ON droop ON fp_ds OFF dsk OFF
[AIS engine v0.66 #0-0]                 received: 0 msgs, total: 0 msgs, rate: 0 msg/s
[AIS engine v0.66 #0-0]                 received: 0 msgs, total: 0 msgs, rate: 0 msg/s
[AIS engine v0.66 #0-0]                 received: 0 msgs, total: 0 msgs, rate: 0 msg/s

SDRangel with the same RSP1A (works perfectly)

Using SDRangel 7.22.6 with AGC ON, RF gain 26, setpoint -40, BW 1536 kHz, SR 2000K — AIS messages decoded immediately. Multiple vessels visible near Montevideo, Uruguay (active port area).

Questions

1. Is the SDRplay API version significant for AIS-catcher v0.66? Could there be an API version mismatch where the device appears to start but the IQ data stream is silently corrupt or not flowing?
2. Is there a way to verify that IQ samples are actually being received? The web viewer at port 8100 doesn't seem to show signal levels when 0 messages are decoded. Is there a debug/verbose flag that would show whether the SDRplay callback is actually delivering samples?
3. The -s 1536K rate causes sdrplay_api_Fail — is this expected for the RSP1A, or does it indicate an API compatibility issue?
4. Any known issues with the pre-built Windows SDRPLAY binary and RSP1A? Should I try building from source instead?

Any guidance appreciated. Happy to provide AIS-catcher -L output or any other diagnostics.

[jvde-github]

Hi Miguel, assume you got it working as closed. Ka? Regards Jasper

[miguelmoraleda]

yup, I find my way to make it work, thank you for the quick reply and awesome project. Best El vie, 27 mar 2026 a las 4:51, Jasper ***@***.***>) escribió:

…

Hi Miguel, assume you got it working as closed. Ka? Regards Jasper — Reply to this email directly, view it on GitHub <#528?email_source=notifications&email_token=AABIVZFVCJFYGBE5OP6Q7KT4SYXH5A5CNFSNUABIM5UWIORPF5TWS5BNNB2WEL2ENFZWG5LTONUW63SDN5WW2ZLOOQXTCNRTGQYDAOBYUZZGKYLTN5XKY43UMF2GKX3DNBQW4Z3FUVSXMZLOOSWGM33PORSXEX3DNRUWG2Y#discussioncomment-16340088>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AABIVZDEALFL22NKM3MJZF34SYXH5AVCNFSM6AAAAACXBHCU2OVHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTMMZUGAYDQOA> . You are receiving this because you modified the open/close state.Message ID: ***@***.*** .com>