MTR 3000 TESTING WITH A R8000 MONITOR

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efc
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MTR 3000 TESTING WITH A R8000 MONITOR

Post by efc »

Hello,has anyone ever tested a MTR 3000 with a General Dynamics R8000 Monitor?The MTR is also in IP site connect.My monitor has DMR autotune,but it looks like it only tests mobiles and portables,plus XPR 8400s.Just curious.

Thanks
John
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escomm
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Re: MTR 3000 TESTING WITH A R8000 MONITOR

Post by escomm »

There is not much tuning you can do with the MTR3000 from an RF perspective. What are you trying to do?
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efc
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Re: MTR 3000 TESTING WITH A R8000 MONITOR

Post by efc »

Hello,what I am trying to do is check the repeater,which is Ip site connect,with the auto tune/tune feature under the test section of the R8000,just like you would a portable/mobile.Which by the by,my monitor cannot do XPR 3500 yet,because General Dynamics has not released th option yet.I am primarily worried about BER.

Thanks
John
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FMROB
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Re: MTR 3000 TESTING WITH A R8000 MONITOR

Post by FMROB »

So, I'm asking cause im curious. I have never had the pleasure of using auto test on anything DMR. In a p25 unit you are actually checking the deviation level at the symbol clock time. From my very small experience, usually if a p25 digital radio was hosed on the BER test, the radio had a runny nose and cough in analog as well.

With that being said, I wonder if the DMR equipment would be the same? My real question is if you tested a repeater in analog, and it was on spec, what part of the unit would cause a failed BER test. I would assume maybe the control module responsible for the clock process, but what else would that foul?

Rob
Last edited by FMROB on Mon Apr 14, 2014 7:26 pm, edited 1 time in total.
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efc
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Re: MTR 3000 TESTING WITH A R8000 MONITOR

Post by efc »

Well,I am concerned about the Radios ability to properly decode encode the proper Bit structure of the signal.I only say that because the R 8000,and i assume the aeroflex,have software to test this component of the radio,which i assume then that testing in analog would not be good enough.Which,I have tested the trbo radios before,and thought well,all ops check good so ,RF is RF and therefore we are good to go.

Thanks
John
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FMROB
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Re: MTR 3000 TESTING WITH A R8000 MONITOR

Post by FMROB »

John,

So I was floating around google land and came across this article http://urgentcomm.com/project-25-mag/ho ... -25-system. It deals with p25, but I am assuming that the same would hold true for DMR to some degree. Interesting read, but it turns out that I at least answered some of my question.

For example "Receiver sensitivity is measured differently in P25 systems than it is in FM systems. While FM usually requires a test of sensitivity using SINAD or distortion, a P25 system, because it is digital, must use a bit error rate, or BER, test. Such tests are done using a defined test pattern as specified in the TIA/EIA-102 CAAA.C standard, usually using the 1011 tone or the 511 (V.52) tone. These tones are locked-down bit patterns, since any variation would cause bit errors. A digital signal generator, or a digital radio test set that can generate these tones, is utilized for this test, during which the RF level is reduced to find the corresponding value for 5% BER. Typically that would be around –116 dBm."

I am back to my other question, if a trbo portable fails ber test, what else in the radio analog wise would not be on target, if anything at all.

Rob
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escomm
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Re: MTR 3000 TESTING WITH A R8000 MONITOR

Post by escomm »

There is no autotune or test for the repeaters

Sorry
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Re: MTR 3000 TESTING WITH A R8000 MONITOR

Post by Bill_G »

FMROB wrote:John,

So I was floating around google land and came across this article http://urgentcomm.com/project-25-mag/ho ... -25-system. It deals with p25, but I am assuming that the same would hold true for DMR to some degree. Interesting read, but it turns out that I at least answered some of my question.

For example "Receiver sensitivity is measured differently in P25 systems than it is in FM systems. While FM usually requires a test of sensitivity using SINAD or distortion, a P25 system, because it is digital, must use a bit error rate, or BER, test. Such tests are done using a defined test pattern as specified in the TIA/EIA-102 CAAA.C standard, usually using the 1011 tone or the 511 (V.52) tone. These tones are locked-down bit patterns, since any variation would cause bit errors. A digital signal generator, or a digital radio test set that can generate these tones, is utilized for this test, during which the RF level is reduced to find the corresponding value for 5% BER. Typically that would be around –116 dBm."

I am back to my other question, if a trbo portable fails ber test, what else in the radio analog wise would not be on target, if anything at all.

Rob
It comes back to the precision modulation discussed in the article. The transmitter has to hit the target dev levels. In analog, you can verify pwr, freq, and dev, but you aren't using a standardized test pattern with a specific dev. Hence the mod fidelity and BER test.
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Re: MTR 3000 TESTING WITH A R8000 MONITOR

Post by FMROB »

Bill,

Interesting, So if the "radio" makes spec deviation in analog it is a possibility that the radio could have bad deviation in digital? My interest is what might cause that.

Rob
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Bill_G
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Re: MTR 3000 TESTING WITH A R8000 MONITOR

Post by Bill_G »

I would think it possible. Since we don't know how or where the specific models store their alignment, it could be possible for an analog mode to operate off a different alignment than a digital mode. It's just like radios had separate wideband and narrowband settings. Proper operation in one mode just means the radio is capable of being aligned in that mode. I imagine it's entirely possible to have a good analog function, and be broken in digital. There may be some global settings, but we would need more information about specific models before we make that assumption.
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efc
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Re: MTR 3000 TESTING WITH A R8000 MONITOR

Post by efc »

Thanks,i am going to read that,and yes Bill and company,what you are saying is my concern.You cannot from what i see ,put a DMR radio in analog,test it and say all is good.That is because of BER.So........if my R8000 cannot properly do a tune and align on an MTR 3000 ,which operates in Trboland,how am I able to really test it,find a problem,fix it.Which of course is the goal in all jobs.Take care of the customer.And I hate playing the guessing came,coukd be this could be that,oh well,send it back to Moto,because somthing is wrong.Thank you for all your responses,I am glad to see that this thread is leading to some good discusdion on the matter.

Thank you all
John
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