Signal Hound ® Frequently Asked Questions
Installing the Software
I have problems installing Spike / Driver problems, etc.
Older FAQ questions:
I installed the software from the web, but I get a "side-by-side installation incorrect" error. What is the fix?
This indicates that you do not have the Visual C++ 2008 Redistributable (x86) installed. This automatically installs from the CD but must be manually installed before you install from the web. Visit our "downloads" page to obtain the redistributable.
I installed the software, but when I run it I get a "ftd2xx.dll not found" error. What is the fix?
This dll is automatically installed after you FIRST install the USB drivers (CDM20802_Setup.exe), and THEN plug in your Signal Hound and wait 15-30 seconds for Windows to configure it. When you see the message, "Your device is ready to use," this dll will be installed.
The USB drivers should install from the CD automatically, but if they do not, manual installation may be required.
I have a USB-SA44B. I just bought a USB-SA124A. What version of software should I use?
The USB-SA124A requires version 2.13 or newer.
You can uninstall version 2.12 or earlier versions and install 2.13, to be used for both Signal Hound models.
Using the Signal Hound
I am trying to capture an FM modulation envelope, but the modulation seems clipped or inclomplete. What is happening?
The most likely cause of this is the software image rejection. From the control panel, toggle image reject OFF. This will now use only high-side mixing, instead of masking high-side and low-side together.
My phase noise is higher with the internal oscillator than with an external timebase. Why is this?
The internal TCXO has higher phase noise than a precision external reference. At 1 GHz RF, you typically experience -55 dBc/Hz @ 10 Hz offset using the internal timebase. This typically improves to -83 dBc/Hz with an external timebase.
I get some spurs when I am a few KHz away from 1 GHz. Is this normal?
Multiples of 10 MHz have known residual and spurious intermodulation behavior. Residuals as high as -85 dBm (0 dB attenuator) may be observed. Spurs as high as -45 dBc may also be observed at certain frequencies when your RF signal is at a high level, near but not exactly on a multiple of 10 MHz.
If you can, avoid these areas. If not, try adding a 20 dB EXTERNAL attenuator and set the internal attenuator to 0 dB. If this still does not reduce the spur to an acceptable level, you may try to use an external timebase set to a frequency of e.g. 10.02 MHz. This will turn off the internal TCXO and avoid harmonics at exact 10 MHz multiples.
I don't see the 1, 3, 10 pattern for my RBWs. Why not?
You can set your desired RBW, within the range allowed by the software, in powers of 2. For example the RBWs between 100 Hz and 1 KHz(inclusive), change from 100 Hz, 300 Hz, and 1 kHz, to 100 Hz, 200 Hz, 400 Hz, and 800 Hz.
Please note that not all RBWs are available for all spans. If an RBW would yield a sweep of less than 100 points or more than 16,000 points, it may not be available.
My noise floor comes WAY up as soon as I span above 200 MHz. Why?
This is where the I/Q receiver turns off and the IF power detector turns on. The sweep becomes faster but with a higher noise floor.