MDO34 Spectrum Analyzer Range

I've been setting up the MDO34 to a few different function generators in an attempt to read a signal using the RF channel. In terms of visibly seeing a response at high frequency, there isn't any issue. For sine waves, pulses, ramps, etc. there aren't any issues. However, in the low range of the spectrum at 10Hz to 1.5 kHz, the response is generally quite slow without adjusting the RBW. Lowering the RBW helps with the speed of the acquisition - but the reading seems to changes drastically from what is being sent to the MDO34. For example, providing a 30.0000Hz, 10.0Vpp signal into the RF, the MDO34 periodically recognizes 30.6kHz - 30.8kHz peaks at ~ -35.7dBm. There's some expected ringing at 60kHz and 9kHZ at similarly valued peaks. The spectrogram shows a fairly noisy area around 0.00Hz, and the ringing peaks are easily identifiable but also contain a notable spread.

The RF badge settings are at:j
Reference Level:0.00 dBm
Scale: 10dB/div
Position: -2.46 div
Spectrum Traces: Normal + Peak
Detection Method: Auto
Spectrogram: On
Attenuation: 1.00 X

Waveform View Settings:
Threshold: -50.0 dBm
Excursion: 30.0 dB
Quantity: 5
Readout: Absolute
Peak Markers: On
Spectrogram: On

Graticule Style: Full
Graticule Intensity: 75.0%

Horizontal Settings:
Center Frequency: 45.000 kHz
Span: 110.000 kHz
Start Frequency: -10.000 kHz (to see 0Hz)
Stop Frequency: 100.000 kHz
RBW Mode: Auto
Span : RBW -> 20 : 1
Window: Kaiser

For the sake of clarity, the function generator I'm using is the Wavetek 10 MHz DDS Function Generator Model 29. I have used other function generators but the values I'm seeing have been independent of the input. I've checked the input using the other channels and the input is reliable from the generator. I'm connecting the output of the Wavetek to the RF input using a BNC cable. The cable is unusually long, as maybe 20ft. The distance between them is less than two feet and I don't suspect the connection is having a large effect. I used the provided adapter with the MDO34 to get the BNC into the RF channel.

I'm also making use of an external keyboard to make the oscilloscope values easier to manipulate. I don't expect this to have any effect, but I would rather err on the side of too much information than too little.

When it arrived I confirmed that the MDO34 was running the most current firmware, and I calibrated the probe used to confirm the behavior of the function generator in advance of running anything. The boot-up sequence has gone smoothly each time. Due to hard drive rules and policies I don't have an easy way to provide any images at the moment, but I may be able to later on in the correspondence.

Hello,

The slow spectrum update rate that you are seeing at low frequencies is normal for the MDO34. This is due to the MDO43 being a fourier transform based spectrum analyzer. It needs to acquire a long sample in order to resolve low frequency signals. There are two ways to improve the refresh rate, the first being increasing the RBW like you have already found. The second method would be to use an analog channel and applying an FFT to it using the math channel. You can load the attached setup file as an example.

I have been unable to recreate the issue with the peaks periodically being displayed at the wrong frequency.

I do have a couple of other notes that you may want to keep in mind when working with the spectrum analyzer on the MDO34. The first is the input power rating for the RF channel is limited to +20dBm, while 10Vpp is roughly 24dBm. Going beyond this limit may cause damage to the RF channel.
The second is that the RF channel is speced from 9kHz to 1GHz or 3GHz. You may see significant attenuation below 9kHz.
The spike that you are seeing at DC is normal for all spectrum analyzers.
Finally, there has been a firmware update since you created this case, it can be found at the following page: https://www.tek.com/en/support/software/firmware/3-series-mdo-firmware-v11215