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Andrew,
The BB60D was a complete overhaul of the C. Every part was selected to optimize dynamic range for the power budget. The first thing people notice is that full sensitivity is reached with a -30 dBm reference level instead of a -50 dBm, so signals have to be 20 dB stronger to overload. The second is with preselection, signals at 1/2x or 2x your signal of interest are filtered before any amp or mixer.
Being that close, the jammer won’t be filtered out by the preselector, but the extra 20 dB before overload will make a big difference.
It looks like the preselector band breaks didn’t make it into the manual. They are at 130, 210, 310, 450, 650, 950, 1350, 1950, 3010 and 4210 MHz.I suppose if the problem is locating an interfering transmitter, a directional antenna and walking around your job site might do the trick. You can get a log periodic directional antenna for $70 or so from Digi Key. https://www.digikey.com/en/products/detail/te-connectivity-linx/ANT-DB1-LP-RM-01-N/2402472
Ethan,
This is a tricky problem. The first solution that springs to mind is that we are developing a phase coherent multi-channel system. This would be how this problem is generally solved (e.g. MUSIC algorithm, etc).
Short of that, if you had two systems, and arranged the antennas such that the signals arrived at different amplitude ratios or with different phase offsets, a little clever math could separate the signals.The other thing that can invalidate noise measurements is having spur reject mode on. And, of course any averaging done in log units (e.g. averaging points as dBm instead of mW).
Can you confirm that when you “averaged” the sweeps it was in power units, not log units?Quadsat,
Can you please confirm that your trace type is Clear / Write? The log averaging when trace averaging is active will invalidate noise measurements.About 10 years ago, we offered raw IF output. The challenge is that without corrections, the data is not very useful for most tasks. And those corrections are built from real-time temperature data. We don’t have any IP for generating these after the fact. It ends up being a pretty big filter to compensate for the IF SAW filter ripple.
Long story short, we recommend using a CPU with a bit more horsepower, rather than trying to get around the real-time processing.
You could also look at the SP145, which has a much lower CPU load when streaming.
I can’t provide schematics, and opening the case will void the warranty. But there is a 10 MHz TCXO on the board. We have a software correction for its measured frequency though, which might make it challenging to do what you want.
Matt,
Unfortunately we do not have a STEP file for our SA-series. The closest would be the BB60C, but the SA44 is 1 inch shorter, uses a USB 2.0 type B, and has a slightly lower SMA output.
https://signalhound.com/wp-content/uploads/2024/02/5146-9941_BB60C_defeature_artwork.STEP_.zipEduardo,
Can you measure the signal just fine using the Spike software, and are trying to automate it? If so, read through our SCPI documentation in the SDK and let us know how you’re trying to connect (socket / VISA) and what errors you’re seeing. https://signalhound.com/news/scpi-automation-of-signal-hound-spectrum-analyzers/ABorel,
I’m not sure what you’re doing on the receive side, but something like the BB60D, using the digital modulation analysis tools, would be able to lock on and demodulate the (amplified then attenuated) QPSK waveform, and give you an EVM (error vector magnitude) related to the linearity of the amplifier. It can be fairly tricky to check your I and Q symbols without some sort of digital modulation analysis, as there is a delay and phase rotation between the transmitter and receiver, even on the same time base.Kaiser,
I’m curious about the coordinating of the two SM’s. Are they both producing a GPIO output that the FPGA is using to coordinate the signal generation? Do you monitor the two GPIO outputs continuously? Does the bug follow e.g. SM #2 trigger arriving before SM #1? Or SM #2 getting a full sweep ahead or behind SM #1?
Our sweeps are not deterministic, so I can certainly see some variance in timing between the two SM’s playing a role in this.
If you could use something like I/Q streaming, and have the FPGA generate the trigger, or have SM #1 sweeping and generating the trigger and SM #2 streaming at one of the frequencies with a trigger input, something like this might be more solid. Just my thoughts…Good news. Thanks for the update, and for sharing what fixed it!
One thing to try is the CDM Uninstaller with VID 0403 and PID 6010. Sometimes the first install goes south on a particular computer and this is the only way to get it functional. https://ftdichip.com/utilities/
MGielen,
If you can get Serial Converter A and B to show up, the next thing to check is if the VCP driver is being loaded. It should *not* be loaded, as it is not compatible with our firmware.
The VCP Driver can be unloaded by going to Device Manager –> USB Controllers –> USB Serial Converter A –> Advanced, and un-checking the “Load VCP” box, then repeating for Serial Converter B. If this does not work, please email our support team.
The SA124B should be used with a Y cable to provide extra power. If you are using a standard USB cable, especially with a laptop, it may not be getting enough voltage. 4.75V at the SA124B is ideal, but it will operate down to 4.5V. Below 4.5 volts there will be issues.Unfortunately the TG44A only has a 10 MHz output. You can use this for 0 ppm relative accuracy between the TG and SA, but for absolute accuracy, you would need a TG124A or VSG60A instead of the TG44, both of which can accept a 10 MHz input. The phase noise on the VSG60A will be much, much better than the TG124A.
Ed,
If you email support (at) signalhound, we can send you the BB60C Statement of Volatility.
To sum up, the onboard flash is used only for firmware and correction data. All instrument state and waveform capture data is stored on the PC.Thank you for your suggestions! I’ll forward them to the software team.
To clarify, the phase noise of the OCXO itself, at a 10 Hz offset, should be better than -105 dBc/Hz. Generally to measure these numbers, a phase noise tester will need a significant number of correlations.