using a realtime specan as scalar network analyser

Hey there,

I’m interested in the B60C (or even a B60A, really..) as it’d be very nice to be able to look at everything going on in an area of interest and not be relying on things happening when you happen to be sweeping across a frequency.

However one of the things I need to do in my work is matching networks, filters, antennas, etc etc.. so I will be needing a TG too.. (trying really hard to not need a VNA too as well…)

I see that you’re making the TG series of units compatible with the B60, which is great to hear, but now I’m thinking – when you have a realtime spectrum analyser is the whole need for tracking the scanning frequency kind of moot? couldn’t you use a wideband noise source in that case? I know I’m not the most expert RF person in the world, so was wondering – can anyone tell me what’s the benefits/shortcomings of such an idea?

Julian,
I might be the best person to answer this. Yes, a good noise source will work, but it will suffer from:
1) Dynamic range. Since your energy is spread through the entire spectrum, the energy at each frequency bin is quite a bit lower. You might only get 40 dB of dynamic range, instead of 90 ish.
2) Nonlinearities. If you are trying to test the frequency response of a device, and “zero out” the response at some maximum amplitude for best signal-to-noise ratio, you may have significant intermodulation products affecting your readings. When you insert your DUT and filter some of them out, your flatness may be less than ideal.
3) Lack of automated software support. With the TG44AA / TG124A, you get software specifically written to do the task, saving you time and potential errors.

aaah… yeah. Point 1 kind of kills it for serious measurements. Hadn’t thought of how those aspects of the approach might effect the measurement quality so badly.

But very good to know that it’d still be an option for doing some basic rough measurements.

Hi,
I have a little MiniVNA-tiny from miniradio solutions.
Works very well though there is room for improvement and the UI is clunky compared to Spike…
J

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