Wednesday, 10 July 2013

Agilent E4406A

I have now added a nice piece of used test gear to my lab. The E4406A is a
Vector Signal Analyser or VSA. The unit I obtained was originally designed
for testing Cellular Radio base stations. Unlike a Spectrum Analyser it is
a wideband receiver with an ADC at the end. It has a bandwidth of 10 MHz
and will tune anywhere up to 4 GHz.. You can then do time or frequency
domain measurements. In the picture I have selected WCDMA mode, which
is a 3.84 MS/S QPSK signal to analyse the output of DATV-Express. If you
enter the advanced mode you can change the symbol rate and filter roll off
to match those of DVB-S. The unit also has a Basic mode which is modulation
agnostic. Another nice feature is the very, very clean synthesiser it uses allowing
much more precise measurement of oscillator phase noise than I can currently do.
It has a nice programming interface which will allow other measurements to be
made. All in all a very nice piece of gear for the price I paid. As you can see
DATV-Express passes with flying colours. 


  1. Hello,

    I'm too the owner of a E4406A. I'm trying to implement the option 300 to get the 321.4 MHz IF signal.
    Did you find the type of strange connector on the A17 assembly to get this signal?

    Thank you for your answer.

    Jean-Francois F4DAY

    1. Hello Jean-Francois. No I haven't, I was assuming it was an SMA but from
      your comment it obviously isn't. I need to change the battery backup
      as well, which appears to need a complete disassembly to get to the
      CPU board. Please keep me informed if you find further information.

      - Charles

    2. Charles,

      After two hours searching, I have found the answer:

      To connect properly the 321.4 MHz IF output of the A17 assembly I only need a 1.0/2.3 backplane plug connector (DIN 41626).
      This kind of product is available at Mouser for less than 10 euros.

      Thank you again.

      Jean-Francois FOURCADIER, F4DAY

    3. Thanks for the information Jean-Francois. All I need to know now is
      how long the cable needs to be :)

      - Charles

  2. Hello Charles.
    I also have got an e4406a.
    But i noted soms strange behavior of the marker in the basic mode.
    I dont know of this is normal or an misalignment.
    All test on start up are succes.
    Span 10 Mghz / 50Mhz unmodulated signaal on CF
    If i use a marker and then search ,the freq reading is spot on 50.00000Mhz.
    But if i move the CF setting to say 55Mhz
    Then marker and search ,and then there is a difference in the marker reading
    Marker freq is then eg 50.03457Mhz.
    I do not know if this is normaal or i have missed a setting.
    Does someone have a clue ?


    1. Hello Andre,
      I think this is because it is not a spectrum analyser.
      It uses an FFT to show the spectrum. On mine a
      10 MHz span uses a default FFT size of 1024 points
      which would give a resolution of about 10 KHz.
      If you change the resolution bandwidth you will
      probably get more accurate results.

      Just a guess

      - Charles

    2. ok charles

      thanks for your reply
      but i was curious if your device also did the same.
      so i am certain it is not a fault.

      regards ,


  3. I couldn't do the test @ 50 MHz but I did it @ 100 MHz and got similar results to

    1. OK Charles

      Thanks for your reply.
      Now i know this is due to the fact
      That device is nog a real spectrum.
      But i must say : what a Nice piece of equipment for the radio ham.
      Also the powermeter function is very Nice.

      Regards ,
      Andre (PE1-IDY)

    2. Yes it is a nice piece of gear. I made a very low offer
      to a seller on eBay and to my surprise he accepted.
      When I am feeling brave I am going to bring out the IF
      to the back panel then digitise it. I did play about with
      downloading data from it via the Ethernet socket and
      processing on a Linux PC but the ADC is fairly low
      resolution so I think the IF approach is better.

  4. Hello Charles I have also acquired one. I am an RF engineer by trade and I use the very latest Agilent ESA, PSA series spectrum analysers. I got mine for an astonishing price and as you say a good LO with low phase noise. Not to mention the RBW.

    Quite excellent indeed.

    I see that John Miles KE5FX PN application now works with the E4406A!


    Conrad G0RUZ

    1. It will be even better when I can get hold of an inexpensive DIN 41626
      to hookup the IF out. Another idea I had was using the SCPI protocol
      to connect it up to my Linux machine. I have managed to extract samples
      from it and process then on the PC but the transfer rate is quite slow.

      Another thing I need to do is replace the battery in it. Of course they have
      not put that in an easy to get to place!

      The unit has proved very helpful for testing of DATV-Express so it was
      well worth the money.

      - Charles

  5. This comment has been removed by the author.

  6. Charles is there any way of just displaying the Spectrum screen or the IQ polar screen rather than the dual display?

    I have just obtained a Prologix GPIB-USB controller and will be playing with that tomorrow. I have soft-plot for data grabbing.


    Conrad G0RUZ

    1. Hello Conrad, I believe you can use the select window
      and zoom buttons at the bottom. If you don't get anywhere
      with the GPIB-USB card and you are into a bit of
      C programming. I can send you the program I wrote to
      read samples over the Ethernet interface.
      The only issue is you have to set the IP address and
      enable the interface each time you power the unit up.
      (Another reason to replace the internal battery).

  7. Hi Charles yes you are quite right, I found this about an hour ago. A case of RTFM! I have a prologix USB-GBIP interface and I am currently using the KE5FX PN application to acquire a plot of an LO source. It's seems to take an awfully long time though.


    Conrad G0RUZ

    1. Hi Conrad, the Ethernet interface is a bit faster when using the KE5RX
      tools. It is a shame he does not give a few more reference traces.

  8. Charles

    I also got a E4406A , and would love to implement the OPT-300
    If you make one please write some more info on the 1.0/2.3 backplane plug (ie. PN and where to get) , and the length of the cable you have used.

    I'd also like go get the sourcecode of the Linux Xfer program you have written for the Ether interface. Would it be possible to post an "url" to a .tgz

    Carsten OZ1FTG

  9. Hello Carsten,

    Here is the code

    It just sets the VSA up and then reads a block of samples but it should be enough to get you going. F4DAY told me the connectors required but I couldn't find a cheap source of them.

    - Charles

  10. Hi Charles,

    How do I run your VectorSignalAnalyser11_07_13 program? In what environment? I'm not a programmer so bare with me. I do enjoy using my E4406A and am always looking to add features. I finally got the "Concatenator" program written by Bert, VE2ZAZ to run but still can't communicate with the E4406 over the ethernet ports (Notebook to E4406A) which it's designed to do. His program (written in Python 2.7) gets around the 10 MHz span limitation. Perhaps your program will get me to understand the ethernet communication setup protocols.

    Regards...Bill - N6GHz

  11. Hi Bill, if you are not a programmer then you are probably wasting
    your time because it is an example program written in C to grab
    data from the E4406A. I only made it available so anyone writing
    their own programs would not have to delve through the manuals
    like I had to do.

    - Charles

  12. Hi
    Anyone considere to try modifi one of the popular sdr programs to work with e4406a?

  13. Hello; I see in options list from AGilent that the E4406 can do phase noise plot?? Can anyone verify? I have John Miles code but I am wondering if the 4406 can plot PN on its own, in quasi real time?? thanx

    dan d