wideband audio response test

[Logesh]

Hi,

            I need to do the Wide band audio response test .below is customer procedure.i dont know how to proceed this test.i m using NI5670 RFSG & NI4461 audio analyzer.i need model VI to perform this test.I have attached our test setup diagram for ur reference. Kindly send the model VI file to perform this test . i need the RF generation & audio analyse in single VI.

Note : Below test is carried out using  HP8903B audio analyzer.     

Test Procedure:                    
1. The Audio Generator on the Audio Analyzer is programmed to generate 1000Hz at standard test input level and output is normalized to read 0dB reference level by pressing Ratio & Log In buttons. 
2. Set RF signal level to -84dBm, FM deviation 8 KHz , 30MHz RF frequency & corresponding LO Freq,modulating Frequency 1KHz and around 1Vrms level from Audio Analyzer.
3. Modulating frequency of the Audio Generator is varied from 20Hz to 10 KHz.Measure the audio level at TP8 of BUT in the audio analyzer.
4. Measured level at TP8 of BUT should be within –3dB to +3dB w.r.t.1 KHz modulating signal.      
5. Measure audio output at different frequencies shall be 20 KHz < -20dBm with respect to 1KHz modulating signal.    
 
Test Specifications 
                       Measured wideband audio response at TP8 shall be as mentioned below

Modulating Freq. (Hz.)	Level(dBm), Normalizing to 0dB at 1KHz.
20	+3 to –3
300	+3 to –3
700	+3 to –3
3K	+3 to –3
5K	+3 to –3
10K	+3 to –3
20K	<-20

Regards

Logesh.R

[hoffiz]

Hi Logesh,

From your descriptions this seems to be a very high level application that you would probably be looking at
an Alliance Member.You can refer to this web site for more information: National Instruments Alliance PartnerProgram, AlliancePartner Directory.

Regards

[Logesh]

Hi Jaime,

                     This is not high level application this is a general test in Receiver boards .This test is performed using MG3632 SG & HP8903B

               at customer end. But i need to perform this test using PXI 5670 & PXI4461.what will happen if we press Ratio & login buttons & this

               should be done in PXI4461.Kindly send some details regarding this test.

Logesh.R

Produt application Engg

[hoffiz]

Hi Logesh,

It sounds like, form your last post, you are looking into eveloping this application on your own, instead of looking into our alliance members
solutions. The NICI-4461 is programmed using the DAQmx drivers. You can find some examples n how to program this card by searching for 4461 and selecting examples over
in ni.com, another excellent place for example would be labview->help-.find examples and search for DSA. The 5670 is our rfsg platform and examples ad documentation can beound at: windows start menu -> national instruments->rfsg->examples. For the RFSG a very good place to start would be: “NIF Signal Generators Getting Started Guide” and for the DSA: “Dynamic Signal Analyzers (DSA) Support”.

Your question or affirmation: “what will happen if we press Ratio & login buttons & this should e done in PXI4461” is not very clear. I’m guessing that what your are
trying to say is: "I want the 4461 to behave the same as if you have pressed he Ratio and Login buttons of the MG/HP test machine", is that correct? If that
is the case we don’t know how this test machine works so is a little bit ifficult to replicate it.

If you have more specific question during you project please feel free to post them, and I’ll be more than glad to help you.

Message Edited by Jaime F on 09-18-2008 07:19 PM

[dsb@NI]

Hopefully, you have been able to find the information you need to program the RF and DSA devices. There are numerous techniques that can be used to measure the audio response at various frequencies across the spectrum. Swept sine, stepped sine, multitone, single-tone, and FFT-based frequency response measurements all have their strong points. You  should evaluate the National Instruments Sound and Vibration Measurement Suite for these types of measurements. It ships with VIs to generate and analyze swept sine, tone, and broadband signals. The toolkit also ships with many examples to perform these measurements out of the box with your 4461.

If I read your post question correctly, you will find the functionality to express the gain (ratio of magnitudes) on linear and/or logarithmic (dB) scales. 

[Logesh]

Hi ,

        i need to see the response for 20Hz to 20KHz for my receiver board.i will generate the modulated signal & feeding to Receiver board at wide band audio output in my receiver board .i should see the reponse.I have tested with  VI developed by our programmer but i m not acheiving the output that is same as in customer specification.I have attached the VI for ur reference.Refer it & explain me how to carryout this test.

Modulating Freq. (Hz.)	Level(dBm), Normalizing to 0dB at 1KHz.	Output achieved(Customer)	Output achieved Here
20	+3 to –3	-0.07	different
300	+3 to –3	-0.05	different
700	+3 to –3	0.09	different
3K	+3 to –3	0.06	different
5K	+3 to –3	-0.08	different
10K	+3 to –3	-1.21	different
20K	<-20	-32	different

Logesh.R

[Logesh]

HI jaime,

              Kindly give some suggestion for my previous post.

Logesh.R