What do YOU use a spectrum analyzer for?

[alank2]

Hi Everyone,

I've skimmed the wikipedia page for information about what a spectrum analyzer does, but what I'm wondering from guys here at the forum that use one of these, what do you use it for?  What type of testing?  How does it serve you?

Thanks,

Alan

[marshallh]

Well, I bought mine for looking at spectral content of a DDS function gen, and maybe RF stuff in the future.

[olsenn]

Most people use spectrum analyzers to analyze wireless/radio devices; however, personally, I mostly use mine to check the purity of my signals and to see what frequency content my DUT has beyond the measly 100MHz that my oscilloscope goes to.

[Hydrawerk]

Once I used it as a FM radio. 
http://www.stream.cz/uservideo/545708-spektralni-analyzator-je-fm-radio
http://www.stream.cz/uservideo/539348-02-spektrak-rohde-schwarz-fsl-hraje-jako-fm-radio
http://www.stream.cz/uservideo/535822-spektrak-rohde-schwarz-hraje-jako-fm-radio
Please note that the FM broadcasting is in Czech language.
EDIT: Filmed in an university laboratory.

[Paul Moir]

I don't own one, but the one time I tried to borrow one* was to find the noise source that was tripping a metal detector.

*Unfortunately, the radio place across the street's one was out for cal, and their backup wasn't working.  But fortunately the noise source mysteriously disappeared shortly after my visit.
 

[807]

Checking harmonics & spurious from RF transmitters & signal generators.
Peaking stages in receivers & transmitters.
Aligning RF filters in conjuction with a tracking generator.
Setting FM deviation levels.
Measuring attenuators.

[Psi]

I don't have a spectrum analyser, due to the cost, but it would be useful when building 2.4Ghz and 5.8ghz FPV antennas, something i do quite often.
I could use it to tune my antennas for max gain on a particular channel.

Sadly analysers that do 5.8ghz are big money

[xrunner]

I've skimmed the wikipedia page for information about what a spectrum analyzer does, but what I'm wondering from guys here at the forum that use one of these, what do you use it for?  What type of testing?  How does it serve you?

The model I was used to using was the one shown below (old school now). I worked in an electronics warfare lab in my career. Used to check power level, frequency accuracy (all ours were regularly sent to cal labs), unmodulated spectrum, modulated spectrum, and sidebands. Be careful not to input too much power!

[Legit-Design]

One with quasi peak detector is useful EMC precompliance testing. High power dc/dc -converters without proper filters put out a ton of RF crap. In that case boss was insisting the noises those converters produced in FM-radio weren't an issue.

[fqahmad66]

I use mine to measure Tx health of my Radio Control.

[Rerouter]

Currently i'm trying to use mine as a 2 channel real time digital storage oscilloscope, (Old DATA 6000 Universal Waveform Analyser) and as my understanding increases a platform to make up my own stuff on,

[Clint]

I have a really old one and pretty much only use it to align RF PA's - I am seriously considering buying one of the new Rigol ones now.

[Psi]

I am seriously considering buying one of the new Rigol ones now.

The current models that top out at 3GHz? or are there some new ones?

[olsenn]

The current models that top out at 3GHz? or are there some new ones?

Now (especially) with 10Hz RBW and all other features freely unlockable, the DSA815-TG is by far the best bang for your buck; however, it does top out at 1.5GHz, which might not be good enough for some users. If that isn't an issue though, this is the unit to buy.

[deephaven]

I also use mine for evaluating emissions on my equipment prior to it going to an expensive accredited test lab for the 'proper' testing to CE, FCC etc. It is difficult to get absolute measurements, but it is good for relative measurements. Also, if you have a bit of kit that has passed, you can get an approximate idea of how the other kit is doing. Also made a LISN to evaluate conducted emissions.

[Jon Chandler]

People tend to think of RF spectrum analyzers, but there are also spectrum analyzers that cover the audio frequency range.  Useful for checking frequency response of filters, speakers and other parts of sound systems.

Analyzers of this type are also used for machinery vibration analysis.  The frequency of vibration can pinpoint specific mechanical defects (imbalance, misalignment, pump impeller wear, loose laminations and broken rotor bars in motors, worn couplings, etc) in machinery well before failure occurs.  Studies have shown the machinery condition monitoring programs can save 11x the cost of the program by making minor repairs when needed rather than running a machine tto failure.

[envisionelec]

I have a HP 3561A Dynamic Signal Analyzer and a Anritsu MS-610A + option 2 (QPD) Spectrum Analyzer. I use one as an FFT for audio signals coupled with an HP 8903 Distortion Analyzer. The Anritsu is used for Pre-Compliance testing.

[Alexei.Polkhanov]

I don't have a spectrum analyser, due to the cost, but it would be useful when building 2.4Ghz and 5.8ghz FPV antennas, something i do quite often.
I could use it to tune my antennas for max gain on a particular channel.

Sadly analysers that do 5.8ghz are big money

For 5.8 GHz signal you need at least 12 GHz analyzer to see AT LEAST 2nd harmonic in your signal. For some tests you need o see up to 10 harmonics, so ... 

[valvedoctor]

I have a HP 3561A Dynamic Signal Analyzer and a Anritsu MS-610A + option 2 (QPD) Spectrum Analyzer. I use one as an FFT for audio signals coupled with an HP 8903 Distortion Analyzer. The Anritsu is used for Pre-Compliance testing.

I too have an HP 3561A and an HP8903B, for audio. Both units can go up to 100kHz.

[PA4TIM]

Here a Tek 2710 with TG and a 2712. Both hybrids (digital and analog) 9 kHz to 1800 MHz. A homebrew 1-500 MHz SA and two of my 3 VNA's have an SA mode. I had a Tek cai SA but gave that one away to a friend. I use it for repair, adjusting TX or generators etc. But I use a vna more often as a SA.
http://www.pa4tim.nl/?p=4522 The repair raport of my 2710 for those curious to the inside of a SA and my 2712 is on the picture below