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Tisha,
We are planning a VSG up to and beyond 6 GHz, but we do not presently have anything, and probably won’t for a year or more. For now, depending on the accuracy and linearity you need, you might consider upconverting the VSG25A output (e.g. using “evaluation kits” from Analog Devices), either using an image reject mixer or a filter to reject the image. This might be an acceptable alternative to waiting for a VSG60A or VSG200A.
Of course, there are also other affordable vector signal generators (e.g. used R&S or Agilent generators) that might provide a faster, more accurate and traceable alternative to a DIY project.Saira,
We do not currently have a Linux solution for the VSG25A, aside from a Raspberry Pi 2 solution we came up with for a customer, but that was for an order of 50. Would this be a one off, or something with long term purchases?Thanks for the feedback. We actually have a “mixer offset” in the legacy 2.18 software, but it is difficult to “store thru” without a reference mixer, so it definitely had some shortcomings. I have also wanted to add doubler and tripler testing, but this is limited by the harmonics of the TG itself. Still, this could be overcome with a low pass or something. Definitely good things to consider…
Ash,
It sounds like we may need to look at your SA124B. If you have the equipment, generate a CW signal at 25 MHz, 1 Ghz, 3 GHz, 6 GHz, and 10 GHz, around -10 dBm with a 0 dBm reference level and 100 kHz span. If any of them read more than a few dB off, we will need to repair your SA124B. Email support @ signalhound.com for details.Lou,
The way spur reject works is by mixing the incoming RF using two unique combinations of local oscillator and sometimes a different IF frequency. The results are compared and a signal not present in both is rejected as probable spurious.In essence, a signal that is present for the entire sweep (or, for large spans, the time it takes to sweep 21.4 MHz) will not be rejected or hidden. We show our internal clock noise, rather than hiding it and risking missing an actual signal.
If a signal is pulsed or rapidly frequency hopping, spur reject may reject the actual signal, which is why for these types of signals, spur reject mode must be disabled. To analyze these types of signals, the BB60C is strongly recommended, although if you know the frequency of the signal, the SA44B in real-time mode may work also.
January 29, 2016 at 9:38 am in reply to: The use of a SA44 and TG44 with a GPS locked 10MHz reference source. The TG44A hardware only has a time base output, so the only way to lock the SA44B and TG44A together is with TG 10 MHz –> SA 10 MHz
The TG124A has the ability to input or output its 10 MHz reference, so you could use a GPS 10 MHz to discipline both a TG124A and an SA.
You have firmware version 2.10. Unfortunately, to upgrade to 2.11, you will have to send it in to us. I believe it is a free upgrade, but you must pay shipping. Contact support @signalhound .com for assistance.
I’m glad it helped.
You can turn image/spur rejection off. This will force it to stay in the higher noise state, but also lets spurious signals through. Note that with the SA44B there is a 3 dB correction for broadband noise, as the software image rejection cannot filter out noise at the image frequency.
The BB60C can perform this measurement without the correction.
I would probably start with a BB60C for EMC it already has >50 dB spurious rejection, which is plenty for precompliance testing of unintentional radiators. For intentional radiators, I might just buy a simple high pass filter for looking at harmonics, and a low pass filter for looking at frequencies below the transmit frequency.
Preselection is a pain, and expensive, but when you need it there really is no good substitute. External high pass and low pass filters e.g. from Mini-Circuits, will work for many applications, but they do require manual setup.
Agung,
If the problem is that the USB-SA44B has some LO feedthru which is causing interference, there are several ways to mitigate this.
1) Use a reference level of -30 dBm. This will turn on the RF preamplifier, which also blocks LO leakage. Your leakage should be well below -50 dBm in this state.
2) Add an external 20 dB pad to the input of the SA44B and increase the sensitivity by lowering the reference level. With a 20 dB pad, and a reference level of -40 dBm, your LO leakage should be around -70 dBm.
3) If this is not enough, switching to the BB60C is recommended. Its LO feedthrough is below -80 dBm in all modes, and the LO frequency is >2.4 GHz higher than the signal, so it is very unlikely to interfere.Peter,
Yes, for crystals and narrowband filters, we needed a separate mode with much longer settling time. We chose a specific span, 100 kHz, as the switchover point, assuming that people who want to look at the pass band of a device with less than 10 kHz bandwidth would do it with a narrow span. For wideband rejection, where maybe a parasitic capacitance dominates, the faster sweep mode should work fine.Our web admin fixed the .vi issue. Hopefully this works now.
I sent you the .vi file. I’ll resend it. Hopefully it gets through…
Email support at signalhound dot com and I can send it to you…
Last try…
Not permitted for security reasons?!? Rename it to .vi
I thought I attached it… here it is.
I made a LabView program that opened, set frequency, amplitude, CW mode, waited 3 seconds, then closed the device. The only time I ran into a problem was when I did not close the device before trying to run it. If the device does not close, then when you try to open it, it will give you error -4.
Here it is. Maybe it will help?
sgModulationType is an enum, generally equivalent to an “int”. If you cannot include the header file with the enum (e.g. LabView), you can just use an int.