If you are a newcomer and it seems like SDRuno isn’t running or picking up any signals, CLICK HERE to check our “quick start” guide which covers the four things that are the most likely causes of initial problems.
We list here some of the other common questions about SDRuno
Why is there both a regular version and an “EXTIO” version of SDRuno?
SDRuno evolved from software called Studio 1 which SDRplay acquired in 2016. Studio 1 supported many SDR receivers using the EXTIO interface. Since then we have adapted SDRuno to make optimal use of the RSP family of SDRs. Many of the recent features (such as scanning and band framing) rely on the RSP architecture to work. This is why the EXTIO version has not included some of the newer functions. However the EXTIO version will still give many of the basic features found in the current SDRuno release, if you want to use it with any SDR which supports an EXTIO interface. Be sure that you are launch the right version depending on whether you have an RSP or not. (Please note that if you have an RSP and accidentally launch the EXTIO version, only the “main” control panel will appear and not all the other defaults panels).
What are “LO” and “VFO”?
The LO is the Local Oscillator frequency of the RSP hardware, and this is the synthesizer frequency. It will always be the frequency of the centre of your main spectrum display (SP1) when fully zoomed out. The VFO is Variable Frequency Oscillator and this is used to select individual signals within the viewable spectrum. Here there is always a DC spike and the IF (intermediate frequency) mode determines where the spike appears. In ZIF (Zero IF) mode, the DC spike is at the LO frequency (0 Hz offset). Software is used to remove the spike which can also remove any signal at the LO frequency. This is why you need to apply an offset of a few kHz between the LO and VFO frequencies when operating in Zero IF mode. No such separation is required in LIF mode.
The tuning steps are too coarse or too fine. How do I change them?
The granularity of the tuning steps is preset, but by right clicking within the RX Control frequency window, a drop down choice of “step size” will appear and you can select something more optimum for your use. This setting will be remembered until you change it again or reset all settings to default.
The scanner seems to work but it’s not finding anything. What might be wrong?
If you are scanning a range of frequencies (rather than using your own memory bank), it’s important to make sure that the start of the range and the step-size matches candidate signals that you are seeking. The second most important thing is to select a practical threshold for the signal strength.
If set too low, then every piece of noise will be interpreted as a signal of interest. Too high and nothing will be identified.
The best way to determine a good value for the threshold is to place your VFO on a quiet section of spectrum. Ensure that your filter bandwidth and demodulation choice is set to the types of signal you seek, then make a note of the noise floor on the power meter. Do not estimate the noise floor by looking at the Y-axis of the spectrum display. This will be misleading. You need to use the power meter as this integrates the noise power across the full chosen channel bandwidth. Having done this, now set your scanner threshold to be say 6 – 10 dB greater than this. Then start the scanner.
Why does the spectrum noise floor seem to dip down at each end of the range?
What you are seeing here is the effect of the IF filter in the tuner. For example, this starts to roll off for signals that go beyond +/- 768 kHz of the centre frequency as in Low IF mode (LIF), where the IF bandwidth is limited to 1.536 MHz.
You can widen the IF bandwidth by selecting ZIF (Zero IF) as the IF mode. You can then select a higher sample rate such as say 5 MHz or higher. This will give you more of the spectrum with a flatter noise floor (assuming the floor is naturally flat over that range)
SDRuno does not create a nice layout of panels on my screen. What can I do?
The software is designed to auto-populate with a layout that is defined by the screen resolution. There are some screen resolutions that we have not encountered before and so they are not supported for auto-population. Some of the panels in SDRuno are fixed number of pixels in size and so cannot be stretched. (This is a legacy from when the software was known as Studio 1 and pre-dates our involvement with its development. We do plan to change this when we re-design the GUI in release 2.0) Meanwhile, if this applies to you and laptop screen is small, then we recommend that you reduce your screen resolution. This will increase the size of the non-adjustable panels and then you can pick a supported screen resolution so that auto-population feature will now work. The supported screen resolutions are listed in section 3.9 of the user manual. If you are unable to select one of these resolutions, then you can manually open the panels and design a workspace that suits you best and then save it be pressing the SAVE WS (Save Workspace) button on the Main Panel. That way the workspace will always open this way when you start the software.
Why can’t I tune outside one of the preset (framed) “bands”?
If you choose one of the preset bands within SDRuno it will put the radio into Low IF (LIF) mode and lock the LO as part of the band framing process. The band button will be illuminated green. It is then not possible to select frequencies outside that band (for example by tuning the master VFO frequency in the RX Control panel) unless you first “unframe” the band by selecting the band button so that the green light goes out. The same is true of you are using Omnirig and trying to tune SDRuno from your transceiver. In that situation you will need to turn off LO LOCK in SDRuno and only change bands from the rig. Also make sure that if you do use band framing in SDRuno remember to turn off LO LOCK before changing bands from the rig.
Why does the measured noise level go up as you reduce the RF gain control?
This is because SDRuno always displays the “equivalent noise” at the antenna input of the RSP. What do we mean by “equivalent” noise? A perfect receiver would not add any noise to the received signal. A practical receiver will always add noise due to the imperfections of the mixer and amplifier circuits. As you reduce the RF amplifier gain the noise degradation in the receiver will get worse. SDRuno calculates this and the S meter and spectrum display accordingly. What you observe is that the “noise floor” of the receiver gets worse (increases) as you reduce the gain. The received signal however does not change and will display approximately the same level.
Try this experiment. Tune in a local MW station in AM mode with 6000 Hz. bandwidth. Observe the S meter, the dBm level and the signal-to-noise-ratio (SNR) at maximum RF gain (without overload flashing). Now slowly reduce the RF gain and you will see the following. The signal level on the S meter and dBm level will remain the same (within a few dB or so) but the SNR will slowly get worse. The noise floor of the entire band on the spectrum display will get higher. That is because the internal noise of the RSP is getting worse as you lower the gain and this results in a poorer SNR. It also means weak stations are starting to get buried in receiver noise.
I like SDRuno but I want to run on a different computer platform.
Work is underway to enable us to migrate to multiplatform support for SDRuno – Version 2.0 is on our roadmap – see https://www.sdrplay.com/sdruno-roadmap/ although we are unable to commit the timing for this.
What other enhancements are planned for SDRuno in the coming months?
The planned improvements are shown in our SDRuno roadmap here: https://www.sdrplay.com/sdruno-roadmap/
Be sure to check out the SDRuno manual. Even if you are running your RSP off grid (no internet connected) you can access the full SDRuno manual from within the SDRuno main panel as shown below:
