Too Good to be True

[olsenn]

Apparently, this 4GHz Agilent vector network analyzer is available for 750 EUR as a BuyItNow on eBay! Am I missing something here?

http://www.ebay.co.uk/itm/Agilent-E4406A-Vector-Signal-spectrum-Analyzer-option-BAF-WCDMA-202-EDGE-GSM-/251358751988?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item3a86262cf4

[cyr]

The fact that it's a vector *signal* analyzer?

[quarros]

Apparently, this 4GHz Agilent vector network analyzer is available for 750 EUR as a BuyItNow on eBay! Am I missing something here?

http://www.ebay.co.uk/itm/Agilent-E4406A-Vector-Signal-spectrum-Analyzer-option-BAF-WCDMA-202-EDGE-GSM-/251358751988?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item3a86262cf4

Well it is a specialized test equipment for network analysis. It has a frequency span of 10Mhz so although it can work in a wide range of frequency it cannot show you a full spectrum, makes it useless as a spectrum analyzer . Thats the biggest "drawback" as I see.

But if you already have a spectrum analyzer and and you want to have a greater resolution on a smaller frequency range than it is the perfect companion to you.

Update: I just noticed, the seller is our fellow forum member KJDS.

[ConKbot]

The fact that it's a vector *signal* analyzer?

Nailed it!

Apparently, this 4GHz Agilent vector network analyzer is available for 750 EUR as a BuyItNow on eBay! Am I missing something here?

http://www.ebay.co.uk/itm/Agilent-E4406A-Vector-Signal-spectrum-Analyzer-option-BAF-WCDMA-202-EDGE-GSM-/251358751988?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item3a86262cf4

Well it is a specialized test equipment for network analysis. It has a frequency span of 10Mhz so although it can work in a wide range of frequency it cannot show you a full spectrum, makes it useless as a spectrum analyzer . Thats the biggest "drawback" as I see.

But if you already have a spectrum analyzer and and you want to have a greater resolution on a smaller frequency range than it is the perfect companion to you.

*Cell phone network* analysis, or signal analysis, as its not a VNA, just 'network analysis' alone could be confusing.   Also, the 10Mhz is the realtime bandwidth (I.e. it can digitize 10Mhz of spectrum and run a FFT/DFT on it in real time so you can examine modulation etc), as you can see from the options, it was meant to be used on CDMA, EDGE/ GSM networks.  I havent used a VSA series analyzer before, only the newer MXA series which does support full span as a swept spectrum analyzer. No FFT real time unless your span is under the RTBW.  I cant find anything in a brief peruse of the manual to indicate one way or the other, so find out for sure if youre interested in it as a swept SA. However I'd save my $$$ for a spectrum analyzer with a tracking generator, which is ridiculously useful compared to one without IMO.

[quarros]

*Cell phone network* analysis, or signal analysis, as its not a VNA, just 'network analysis' alone could be confusing.   Also, the 10Mhz is the realtime bandwidth (I.e. it can digitize 10Mhz of spectrum and run a FFT/DFT on it in real time so you can examine modulation etc), as you can see from the options, it was meant to be used on CDMA, EDGE/ GSM networks.  I havent used a VSA series analyzer before, only the newer MXA series which does support full span as a swept spectrum analyzer. No FFT real time unless your span is under the RTBW.  I cant find anything in a brief peruse of the manual to indicate one way or the other, so find out for sure if youre interested in it as a swept SA. However I'd save my $$$ for a spectrum analyzer with a tracking generator, which is ridiculously useful compared to one without IMO.

Sorry my terminology was not up to par. 
Anyways I found an interesting discussion about it:
http://www.home.agilent.com/owc_discussions/thread.jspa?messageID=62538
It seems it has a very low noise-floor.

[ConKbot]

*Cell phone network* analysis, or signal analysis, as its not a VNA, just 'network analysis' alone could be confusing.   Also, the 10Mhz is the realtime bandwidth (I.e. it can digitize 10Mhz of spectrum and run a FFT/DFT on it in real time so you can examine modulation etc), as you can see from the options, it was meant to be used on CDMA, EDGE/ GSM networks.  I havent used a VSA series analyzer before, only the newer MXA series which does support full span as a swept spectrum analyzer. No FFT real time unless your span is under the RTBW.  I cant find anything in a brief peruse of the manual to indicate one way or the other, so find out for sure if youre interested in it as a swept SA. However I'd save my $$$ for a spectrum analyzer with a tracking generator, which is ridiculously useful compared to one without IMO.

Sorry my terminology was not up to par. 
Anyways I found an interesting discussion about it:
http://www.home.agilent.com/owc_discussions/thread.jspa?messageID=62538
It seems it has a very low noise-floor.

No problem, I'm sure terminolgy varies from place to place anyway. I'm sure there are cell phone network techs who havent touched a VNA and would call the VSA a network analyzer.

Interesting that it doesnt support a sweep! I wonder if its not real-time then, I'd suspect not.

A vector signal analyzer/realtime VSA is basically a tunable RF down converter ( i.e. converts 100-110 MHz to 0-10 MHz) to stuck in front of high-resolution/low noise DSO (I.e. it digitizes the waveform) where it then processes the signal to give frequency domain information instead of time domain. A realtime VSA can continuously acquire the data, and process it before the next chunk of data is ready.  A 'plain' vector signal analyzer will have some deadtime.

  shows what signal analyzers can do vs swept spec-ans.