Re: [USRP-users] B210 mini I/Q imbalance?

[Marcus D. Leech via USRP-users]

On 05/05/2019 01:12 PM, Brian Padalino wrote:

Since it's AM, try shifting your center frequency by a little bit.

Extract the envelope the same way, though.

My thought is the DC cancellation circuitry in the 9361 is killing 
your AM waveform, so use a low-IF approach instead.


Brian
You beat me to it.  Yes, this will be true of most direct-conversion 
architectures--there will be DC-offset removal in the analog
  (or digital) pathways before samples are delivered to the host. That 
removal process will turn the DC anomaly from a large
  spur to a notch, so if you are doing narrow-band AM demodulation at 
"DC" in the complex signal domain, some of that signal

  will have  been removed.   Offset tuning eliminates this issue.




On Sun, May 5, 2019 at 1:05 PM franz kurniawan via USRP-users 
mailto:usrp-users@lists.ettus.com>> wrote:


I reduced to -40db, -50db and have the same result..

I attached the pictures of b200mini vs other SDR with the same
signal generator..

I expect the same result with the 'other SDR' result..
The IQ data of b200 is seems to be incorrect (imbalance? )

I have tried the uhd of these version :
v3.14.0.0-rc3 ,
release_003_007_001,
release_003_010_001_000

But all have the same result..

I tried to disable the set_auto_iq_balance to both false and true,
but have no effect..

Thank you

On May 5, 2019 11:27 PM, "Marcus D Leech" mailto:patchvonbr...@gmail.com>> wrote:

-20dBM is loud. Try backing the generator down to -40dBm


Sent from my iPhone

On May 5, 2019, at 12:14 PM, franz kurniawan
mailto:digitalturtle2...@gmail.com>> wrote:


I set the generator at -20db and b200 gain at 50..
I check that there is no cutoff at the usrp output and the
input to AM demod block..

Below are the setting of uhd block in gnuradio
Samp rate 500k
Output type float32
Sync PC clock
Clock rate 10 Mhz external
Freq 121MHz
Gain 50
Ch0 Bandwidth 20


Thank you

On May 5, 2019 11:05 PM, "Marcus D Leech"
mailto:patchvonbr...@gmail.com>> wrote:

What output level for the generator? What gain setting on
the b205?


Sent from my iPhone

On May 5, 2019, at 11:58 AM, franz kurniawan
mailto:digitalturtle2...@gmail.com>> wrote:


So, i try to make AM receiver..
And the resulted demodulated audio was distorted from
its original signal..
So, at this experiment i used signal generator to make
AM with sine wave modulated signal..
I expect to get pure sine wave signal after AM demod
process..
However, the sine wave is distorted as attached picture

I compared with another brand SDR and can get my
expected signal..
So i guess there is some problem with the b210mini

Thank you



On May 5, 2019 10:28 PM, "Marcus D. Leech via
USRP-users" mailto:usrp-users@lists.ettus.com>> wrote:

On 05/05/2019 10:53 AM, franz kurniawan via
USRP-users wrote:

Dear USRP users,

I used b210mini and encounter I/Q imbalance as
below picture..
As a result, the analog signal demodulation was
distorted and result a crappy sound..
I
Is there any workaround regarding this issue?

Thank you


Not sure what you mean.  The I/Q seem to be about
90deg out of phase wrt one another, which is exactly
what you'd expect.

Could you describe what it is you're trying to do?
Something with an audio demodulator?



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Re: [USRP-users] B210 mini I/Q imbalance?

[franz kurniawan via USRP-users]

Hi brian,

You are absolutely correct !
after i shifted 2Khz , i can get the expected signal..

In term of usrp sink (AM Tx), do you think that the same condition might
occurred?

Thank you



On May 6, 2019 12:12 AM, "Brian Padalino"  wrote:

Since it's AM, try shifting your center frequency by a little bit.

Extract the envelope the same way, though.

My thought is the DC cancellation circuitry in the 9361 is killing your AM
waveform, so use a low-IF approach instead.

Brian

On Sun, May 5, 2019 at 1:05 PM franz kurniawan via USRP-users <
usrp-users@lists.ettus.com> wrote:

> I reduced to -40db, -50db and have the same result..
>
> I attached the pictures of b200mini vs other SDR with the same signal
> generator..
>
> I expect the same result with the 'other SDR' result..
> The IQ data of b200 is seems to be incorrect (imbalance? )
>
> I have tried the uhd of these version :
> v3.14.0.0-rc3 ,
> release_003_007_001,
> release_003_010_001_000
>
> But all have the same result..
>
> I tried to disable the set_auto_iq_balance to both false and true, but
> have no effect..
>
> Thank you
>
> On May 5, 2019 11:27 PM, "Marcus D Leech"  wrote:
>
> -20dBM is loud. Try backing the generator down to -40dBm
>
>
> Sent from my iPhone
>
> On May 5, 2019, at 12:14 PM, franz kurniawan 
> wrote:
>
> I set the generator at -20db and b200 gain at 50..
> I check that there is no cutoff at the usrp output and the input to AM
> demod block..
>
> Below are the setting of uhd block in gnuradio
> Samp rate 500k
> Output type float32
> Sync PC clock
> Clock rate 10 Mhz external
> Freq 121MHz
> Gain 50
> Ch0 Bandwidth 20
>
>
> Thank you
>
> On May 5, 2019 11:05 PM, "Marcus D Leech"  wrote:
>
>> What output level for the generator? What gain setting on the b205?
>>
>>
>> Sent from my iPhone
>>
>> On May 5, 2019, at 11:58 AM, franz kurniawan 
>> wrote:
>>
>> So, i try to make AM receiver..
>> And the resulted demodulated audio was distorted from its original
>> signal..
>> So, at this experiment i used signal generator to make AM with sine wave
>> modulated signal..
>> I expect to get pure sine wave signal after AM demod process..
>> However, the sine wave is distorted as attached picture
>>
>> I compared with another brand SDR and can get my expected signal..
>> So i guess there is some problem with the b210mini
>>
>> Thank you
>>
>>
>>
>> On May 5, 2019 10:28 PM, "Marcus D. Leech via USRP-users" <
>> usrp-users@lists.ettus.com> wrote:
>>
>> On 05/05/2019 10:53 AM, franz kurniawan via USRP-users wrote:
>>
>>> Dear USRP users,
>>>
>>> I used b210mini and encounter I/Q imbalance as below picture..
>>> As a result, the analog signal demodulation was distorted and result a
>>> crappy sound..
>>> I
>>> Is there any workaround regarding this issue?
>>>
>>> Thank you
>>>
>>>
>>> Not sure what you mean.  The I/Q seem to be about 90deg out of phase wrt
>> one another, which is exactly what you'd expect.
>>
>> Could you describe what it is you're trying to do?  Something with an
>> audio demodulator?
>>
>>
>>
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>>
>>
>> 
>>
>>
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Re: [USRP-users] B210 mini I/Q imbalance?

[Brian Padalino via USRP-users]

Since it's AM, try shifting your center frequency by a little bit.

Extract the envelope the same way, though.

My thought is the DC cancellation circuitry in the 9361 is killing your AM
waveform, so use a low-IF approach instead.

Brian

On Sun, May 5, 2019 at 1:05 PM franz kurniawan via USRP-users <
usrp-users@lists.ettus.com> wrote:

> I reduced to -40db, -50db and have the same result..
>
> I attached the pictures of b200mini vs other SDR with the same signal
> generator..
>
> I expect the same result with the 'other SDR' result..
> The IQ data of b200 is seems to be incorrect (imbalance? )
>
> I have tried the uhd of these version :
> v3.14.0.0-rc3 ,
> release_003_007_001,
> release_003_010_001_000
>
> But all have the same result..
>
> I tried to disable the set_auto_iq_balance to both false and true, but
> have no effect..
>
> Thank you
>
> On May 5, 2019 11:27 PM, "Marcus D Leech"  wrote:
>
> -20dBM is loud. Try backing the generator down to -40dBm
>
>
> Sent from my iPhone
>
> On May 5, 2019, at 12:14 PM, franz kurniawan 
> wrote:
>
> I set the generator at -20db and b200 gain at 50..
> I check that there is no cutoff at the usrp output and the input to AM
> demod block..
>
> Below are the setting of uhd block in gnuradio
> Samp rate 500k
> Output type float32
> Sync PC clock
> Clock rate 10 Mhz external
> Freq 121MHz
> Gain 50
> Ch0 Bandwidth 20
>
>
> Thank you
>
> On May 5, 2019 11:05 PM, "Marcus D Leech"  wrote:
>
>> What output level for the generator? What gain setting on the b205?
>>
>>
>> Sent from my iPhone
>>
>> On May 5, 2019, at 11:58 AM, franz kurniawan 
>> wrote:
>>
>> So, i try to make AM receiver..
>> And the resulted demodulated audio was distorted from its original
>> signal..
>> So, at this experiment i used signal generator to make AM with sine wave
>> modulated signal..
>> I expect to get pure sine wave signal after AM demod process..
>> However, the sine wave is distorted as attached picture
>>
>> I compared with another brand SDR and can get my expected signal..
>> So i guess there is some problem with the b210mini
>>
>> Thank you
>>
>>
>>
>> On May 5, 2019 10:28 PM, "Marcus D. Leech via USRP-users" <
>> usrp-users@lists.ettus.com> wrote:
>>
>> On 05/05/2019 10:53 AM, franz kurniawan via USRP-users wrote:
>>
>>> Dear USRP users,
>>>
>>> I used b210mini and encounter I/Q imbalance as below picture..
>>> As a result, the analog signal demodulation was distorted and result a
>>> crappy sound..
>>> I
>>> Is there any workaround regarding this issue?
>>>
>>> Thank you
>>>
>>>
>>> Not sure what you mean.  The I/Q seem to be about 90deg out of phase wrt
>> one another, which is exactly what you'd expect.
>>
>> Could you describe what it is you're trying to do?  Something with an
>> audio demodulator?
>>
>>
>>
>> ___
>> USRP-users mailing list
>> USRP-users@lists.ettus.com
>> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
>>
>>
>> 
>>
>>
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Re: [USRP-users] B210 mini I/Q imbalance?

[Marcus D Leech via USRP-users]

-20dBM is loud. Try backing the generator down to -40dBm


Sent from my iPhone

> On May 5, 2019, at 12:14 PM, franz kurniawan  
> wrote:
> 
> I set the generator at -20db and b200 gain at 50..
> I check that there is no cutoff at the usrp output and the input to AM demod 
> block..
> 
> Below are the setting of uhd block in gnuradio
> Samp rate 500k
> Output type float32
> Sync PC clock
> Clock rate 10 Mhz external
> Freq 121MHz
> Gain 50
> Ch0 Bandwidth 20
> 
> 
> Thank you
> 
>> On May 5, 2019 11:05 PM, "Marcus D Leech"  wrote:
>> What output level for the generator? What gain setting on the b205?
>> 
>> 
>> Sent from my iPhone
>> 
>>> On May 5, 2019, at 11:58 AM, franz kurniawan  
>>> wrote:
>>> 
>>> So, i try to make AM receiver..
>>> And the resulted demodulated audio was distorted from its original signal..
>>> So, at this experiment i used signal generator to make AM with sine wave 
>>> modulated signal..
>>> I expect to get pure sine wave signal after AM demod process..
>>> However, the sine wave is distorted as attached picture
>>> 
>>> I compared with another brand SDR and can get my expected signal..
>>> So i guess there is some problem with the b210mini
>>> 
>>> Thank you
>>> 
>>> 
>>> 
>>> On May 5, 2019 10:28 PM, "Marcus D. Leech via USRP-users" 
>>>  wrote:
 On 05/05/2019 10:53 AM, franz kurniawan via USRP-users wrote:
 Dear USRP users,
 
 I used b210mini and encounter I/Q imbalance as below picture..
 As a result, the analog signal demodulation was distorted and result a 
 crappy sound..
 I
 Is there any workaround regarding this issue?
 
 Thank you
 
 
>>> Not sure what you mean.  The I/Q seem to be about 90deg out of phase wrt 
>>> one another, which is exactly what you'd expect.
>>> 
>>> Could you describe what it is you're trying to do?  Something with an audio 
>>> demodulator?
>>> 
>>> 
>>> 
>>> ___
>>> USRP-users mailing list
>>> USRP-users@lists.ettus.com
>>> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
>>> 
>>> 
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Re: [USRP-users] B210 mini I/Q imbalance?

[franz kurniawan via USRP-users]

I set the generator at -20db and b200 gain at 50..
I check that there is no cutoff at the usrp output and the input to AM
demod block..

Below are the setting of uhd block in gnuradio
Samp rate 500k
Output type float32
Sync PC clock
Clock rate 10 Mhz external
Freq 121MHz
Gain 50
Ch0 Bandwidth 20


Thank you

On May 5, 2019 11:05 PM, "Marcus D Leech"  wrote:

> What output level for the generator? What gain setting on the b205?
>
>
> Sent from my iPhone
>
> On May 5, 2019, at 11:58 AM, franz kurniawan 
> wrote:
>
> So, i try to make AM receiver..
> And the resulted demodulated audio was distorted from its original signal..
> So, at this experiment i used signal generator to make AM with sine wave
> modulated signal..
> I expect to get pure sine wave signal after AM demod process..
> However, the sine wave is distorted as attached picture
>
> I compared with another brand SDR and can get my expected signal..
> So i guess there is some problem with the b210mini
>
> Thank you
>
>
>
> On May 5, 2019 10:28 PM, "Marcus D. Leech via USRP-users" <
> usrp-users@lists.ettus.com> wrote:
>
> On 05/05/2019 10:53 AM, franz kurniawan via USRP-users wrote:
>
>> Dear USRP users,
>>
>> I used b210mini and encounter I/Q imbalance as below picture..
>> As a result, the analog signal demodulation was distorted and result a
>> crappy sound..
>> I
>> Is there any workaround regarding this issue?
>>
>> Thank you
>>
>>
>> Not sure what you mean.  The I/Q seem to be about 90deg out of phase wrt
> one another, which is exactly what you'd expect.
>
> Could you describe what it is you're trying to do?  Something with an
> audio demodulator?
>
>
>
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>
> 
>
>
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Re: [USRP-users] B210 mini I/Q imbalance?

[Marcus D Leech via USRP-users]

What output level for the generator? What gain setting on the b205?


Sent from my iPhone

> On May 5, 2019, at 11:58 AM, franz kurniawan  
> wrote:
> 
> So, i try to make AM receiver..
> And the resulted demodulated audio was distorted from its original signal..
> So, at this experiment i used signal generator to make AM with sine wave 
> modulated signal..
> I expect to get pure sine wave signal after AM demod process..
> However, the sine wave is distorted as attached picture
> 
> I compared with another brand SDR and can get my expected signal..
> So i guess there is some problem with the b210mini
> 
> Thank you
> 
> 
> 
> On May 5, 2019 10:28 PM, "Marcus D. Leech via USRP-users" 
>  wrote:
>> On 05/05/2019 10:53 AM, franz kurniawan via USRP-users wrote:
>> Dear USRP users,
>> 
>> I used b210mini and encounter I/Q imbalance as below picture..
>> As a result, the analog signal demodulation was distorted and result a 
>> crappy sound..
>> I
>> Is there any workaround regarding this issue?
>> 
>> Thank you
>> 
>> 
> Not sure what you mean.  The I/Q seem to be about 90deg out of phase wrt one 
> another, which is exactly what you'd expect.
> 
> Could you describe what it is you're trying to do?  Something with an audio 
> demodulator?
> 
> 
> 
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Re: [USRP-users] B210 mini I/Q imbalance?

[Marcus D. Leech via USRP-users]

On 05/05/2019 10:53 AM, franz kurniawan via USRP-users wrote:

Dear USRP users,

I used b210mini and encounter I/Q imbalance as below picture..
As a result, the analog signal demodulation was distorted and result a 
crappy sound..

I
Is there any workaround regarding this issue?

Thank you


Not sure what you mean.  The I/Q seem to be about 90deg out of phase wrt 
one another, which is exactly what you'd expect.


Could you describe what it is you're trying to do?  Something with an 
audio demodulator?




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