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Justin CrooksModeratorJustin Crooks March 7, 2018 at 10:07 am in reply to: Spike with sa44b on a microcomputer //php bbp_reply_id(); ?>
We have an API for the SA44B that allows it to be used with a Raspberry Pi 2 (and probably on newer versions as well). It is kind of hobbled in this mode, but you can do some basic sweeps and probably even stream 40 kHz of decimated I/Q if you wish. You would be responsible for the software though.
For using Spike, an Intel NUC running Windows can be useful if size is a concern.
Justin CrooksModeratorJustin Crooks February 26, 2018 at 10:22 am in reply to: Floor noise of BB60c //php bbp_reply_id(); ?>
Our noise figure is higher than this, so you would have to use a preamplifier with the BB60C to meet this noise figure.
Justin CrooksModeratorJustin Crooks February 22, 2018 at 11:38 am in reply to: Floor noise of BB60c //php bbp_reply_id(); ?>
Typical noise floor for the BB60C at 800 MHz is around -163 dBm/Hz, so the noise figure is around 11 dB. At 2.4 GHz, typical is -159 dBm/Hz, for a noise figure of 15 dB.
I suppose SNR for the BB60C depends on a lot of things, but a good starting point might be about 44 dB for a 2 MHz signal bandwidth, including phase noise and thermal noise, if I made my measurement correctly.
Justin CrooksModeratorJustin Crooks February 22, 2018 at 10:03 am in reply to: Digital Modulation Analysis //php bbp_reply_id(); ?>
FSK demodulation should work fine for MSK signals
Justin CrooksModeratorJustin Crooks February 15, 2018 at 1:51 pm in reply to: Powering BB60C via external cell phone charger battery //php bbp_reply_id(); ?>
I know of people who have tried this. The short answer is that you *might* break something as you could potentially back-power the USB, but I have not heard of anyone actually breaking something. If your charger puts out a clean 5 V, in theory it could extend your battery life if you had enough watt-hours in your charger. If it is not a clean 5V, it could do bad things, and it might do bad things when its charge runs out.
Does your laptop manufacturer make a higher capacity battery? Or a replaceable battery?
Justin CrooksModeratorJustin Crooks February 12, 2018 at 9:54 am in reply to: Can TG44A stand alone as a CW signal generator? //php bbp_reply_id(); ?>
From the thread you linked to:
“The TG44 can be used as a standalone generator. There is an application called TGStandalone in the Spike application installation directory which allows you to set the frequency and amplitude of the generator.”
You can also set the TG frequency and amplitude using a TG standalone API, available on request. There are no modulation capabilities, just a CW. The TG output has a lot of harmonics, so a low pass filter should be used if you use it over the air, and you should make sure to adhere to any regulations regarding over the air RF transmissions.
Justin CrooksModeratorJustin Crooks February 7, 2018 at 9:57 am in reply to: Self Test fail SA44B //php bbp_reply_id(); ?>
Yes, it looks like the attenuator is broken. You can email support@signalhound.com for information on repairs.
Justin CrooksModeratorJustin Crooks February 5, 2018 at 11:21 am in reply to: Self Test fail SA44B //php bbp_reply_id(); ?>
Ermy,
There are two possibilities:
1) Your attenuator was outside the normal range when it was adjusted. In this case, the amplitudes would read correctly at all reference levels, but the noise floor would come up a few extra dB at certain reference levels.
2) Your attenuator has been slightly damaged (typically from ESD), and only reads correctly at certain reference levels.
This is something we could repair if you are interested.
A good way to manually check your device is to inject a known signal, at -45 dBm or so. Check the reading at -40 dBm reference level, 200 kHz span, and then step the reference level in 5 dB steps up to 0 dBm. If any reading differs by more than 2 dB, your attenuator is probably damaged.
Justin CrooksModeratorJustin Crooks February 5, 2018 at 11:13 am in reply to: Spike on range ~600-900Mhz //php bbp_reply_id(); ?>
Aleks,
Unfortunately this is fairly typical for wide span sweeps. The signal levels should decrease with reference level.
For most of them, if you look at the spur with a span of 200 kHz or less, it will not be there. The spurs are from internal clock harmonics mixing in.
Justin CrooksModeratorJustin Crooks February 2, 2018 at 3:38 pm in reply to: Possibility of adding Trigger out on BB60C ? //php bbp_reply_id(); ?>
Sinisa,
Thank you for your reply. I guess to clarify my answer, the BB60C’s FPGA unfortunately cannot be upgraded in the field. An FPGA update would be a logistical challenge. Even though I think it would be a powerful addition, I think it will have to wait until the next generation.
The SM200A is a product that is actively being developed. And its FPGA is field upgradeable. It is probably practical to add the feature here, even though I realize it won’t help you.Best Regards,
Justin
Justin CrooksModeratorJustin Crooks February 2, 2018 at 11:10 am in reply to: Possibility of adding Trigger out on BB60C ? //php bbp_reply_id(); ?>
Sinisa,
We do not have any plans to add this to the BB60C, although I can definitely see the use cases. I may propose adding Video Trigger Out to our SM200A, which has a much bigger FPGA and more I/O resources.In many cases, you can use the Trigger In for tests of this nature. For example, if your scope or signal source can provide a trigger, this could be sent to the BB60C trigger in.
Hopefully this helps.
Justin CrooksModeratorJustin Crooks January 19, 2018 at 9:27 am in reply to: TG44A as a standalone tracking gen with other vendor spec. analyzer //php bbp_reply_id(); ?>
The TG44A’s firmware is not compatible with other vendors, so you would have to use it as a CW generator, step through a list of frequencies, and make an amplitude measurement with the 3rd party SA. You could automate this, but it would still not be nearly as fast as the TG44A-SA44B combo.
Justin CrooksModerator- This reply was modified 7 years, 9 months ago by
Justin Crooks.
We do not currently have a 3D model of the BB60C, but we do have one of the SA44B. The BB60C is exactly 1 inch longer, and has different end plates. I can send you files on the end plates if you are interested.
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Justin CrooksModeratorJustin Crooks November 21, 2017 at 5:21 pm in reply to: Pulsed RF signal spectrum measurement //php bbp_reply_id(); ?>
In that case, you can look at the phase of the I/Q samples (using atan2). Convert phase to frequency for the instantaneous frequency. You can reduce noise by low pass filtering the frequency results.
Justin CrooksModeratorJustin Crooks November 21, 2017 at 11:49 am in reply to: Pulsed RF signal spectrum measurement //php bbp_reply_id(); ?>
If you are using the API, we provide streaming I/Q data at 40 MSPS, which you could have centered at 3 GHz.
For amplitude, use I*I+Q*Q, and for phase use the atan2 function.
By relative phase, I mean 2 things:
1) If your generator time base does not exactly match the BB60C, the phase angle in the I/Q data will rotate at the frequency difference.
2) If you lock time bases together, there will be a fixed phase offset between the generator and the BB60C. In most cases, there will be a *new* fixed phase offset each time you start I/Q streaming, but exact multiples of 20 MHz may avoid this.
You can download the API manual from our website for more information.
Using the API, you can measure amplitude and phase 40 million times per second. By adjusting sample rate and signal bandwidth, and adding some averaging, you can make more accurate, but slower, amplitude and phase measurements.
Justin CrooksModeratorJustin Crooks November 20, 2017 at 10:54 am in reply to: Pulsed RF signal spectrum measurement //php bbp_reply_id(); ?>
The BB60C would be the only current option for this. It has 27 MHz of instantaneous bandwidth.
In zero span mode, video triggered, you could trigger on the rising edge of the pulse, and observe e.g. 1 microsecond before rising edge and 19 microseconds after, and make measurements on the instantaneous amplitude (including pulse width at 25 nanosecond resolution), frequency, and relative phase of the pulse.
Justin CrooksModeratorJustin Crooks November 20, 2017 at 10:49 am in reply to: TG44A and the BB60C //php bbp_reply_id(); ?>
Tishers,
Yes, the BB60C can be connected to the TG44A using the TG Sync signal to enable scalar network analysis, which provides about 600 frequency/amplitude signals per second.
When doing scalar network analysis, there is no advantage to having the 10 MHz time base connected (the TG reference is uncorrected 1 ppm, the BB60C is corrected, typically < 0.1 ppm initially). But if you need frequency lock between the BB60C and the TG44A, you can connect the TG44A 10 MHz out to the BB60C 10 MHz in. It may be 1 ppm off, but the frequency will be exactly locked (typically when testing phase shift using streaming I/Q data when 0 ppm *relative* frequency error is required).
Justin CrooksModeratorJustin Crooks November 6, 2017 at 10:07 am in reply to: Floor noise of BB60c //php bbp_reply_id(); ?>
Sure, I understand. You may be interested in the SM200A when we come out with it (going in to production next month). The required filters for this are built in, and the dynamic range is much better than the BB60C, so you should see minimal increase in the noise floor when you connect an antenna. Or, if they are completely satisfied with the DRT price and performance, there’s really no compelling reason to switch.
Justin CrooksModeratorPetr,
Internally, this pulse could be generated, but it would only be used internal to the VSG25A to modulate a carrier frequency above 100 MHz. We do not have user accessible baseband signals.
Justin CrooksModeratorJustin Crooks November 3, 2017 at 10:50 am in reply to: Floor noise of BB60c //php bbp_reply_id(); ?>
It looks like the BB60C went from -133 to -112.5, and the DRT went from -128 to -121. This probably reflects how much out-of-band energy is hitting the amplifier, and that amplifier’s linearity. My guess is the DRT uses either a more linear amp, or a smaller passband.
One thing you could try, if you need a lower noise floor in this band, is to add a band pass filter. This should remove some out-of-band energy before it hits the amplifier and bring the noise floor down.- This reply was modified 7 years, 9 months ago by
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