Re: [Discuss-gnuradio] N210 Unsuccessful Ref Lock

[Josh Blum]

On 06/11/2012 05:18 PM, Ryan Wolfarth wrote:
> The clock signal has not been split yet: I'm only testing one N210 to
> verify a reference lock.  We will be using a SRS FS735 distribution
> amplifier for clock splitting.  It outputs 13+/-1 dBm to a 50 Ohm load from
> each output.
> 
> The current dboard is an RFX1800, but we will be using a combination of
> 1200s and 1800s depending on the signal we're capturing.  We changed the
> sleep time in test_dboard_coercion to 5 seconds instead of 1.  I'm going
> perform some more thorough testing, but this looks like a good fix!
> 

Yea, sorry. It looks like there were a few things a little screwy with
the lock detect checking. I will push something tomorrow to make it a
little more consistent.

Thanks!
-Josh

> Thank you,
> Ryan
> 
> On Mon, Jun 11, 2012 at 7:14 PM, Josh Blum <address@hidden> wrote:
> 
>>
>>
>> On 06/11/2012 04:04 PM, Ryan Wolfarth wrote:
>>> Hi all,
>>>
>>> My research group is continuing our setup of two servers with multiple
>>> N210s for a GNSS application.  Each server will have 4 or 5 N210s
>> recording
>>> RF data at frequencies of interest.  All are to be locked to the 10MHz
>>> reference and 1 PPS output from a Septentrio PolaRxS.  I have
>> successfully
>>> tested our PPS arrangement using test_pps_input.  However,
>>> test_dboard_coercion sometimes reports an unsuccessful lock to our
>> external
>>> oscillator.  The number of unsuccessful locks varies with the inputs to
>>> test_dboard_coercion:
>>>
>>> Set1:  "--rx --ref external" reports an unsuccessful ref lock at 1500MHz
>>> Set2:  "--rx --ref external --no_rx_gain" reports an unsuccessful ref
>> lock
>>> at 1500, 1550, 1700, 1750, 1800, 1850, 1900, 1950, and 2000MHz.
>>>
>>> These unsuccessful locks are intermittent.  The results for Set2 don't
>>> worry me so much: we're always running at high gain when recording.  What
>>> is the cause and is there a good solution to this problem?  Our plan is
>> to
>>> have all N210s writing constantly to a ring buffer, but only writing to
>>> file when triggered by an external source.  The reference lock is
>> critical
>>> since we're studying GNSS signals.  Any help is appreciated.  I know this
>>> list usually hits it out of the park, so I'm looking forward to your
>>> responses!
>>>
>>> Thank you,
>>> Ryan
>>>
>>> Setup: Dell PowerEdge R510 running UHD 3.4.2 on Ubuntu 12.04 server.
>>>
>>>
>>>
>>
>> Ryan,
>>
>> Can you tell me which dboard you are using? Its possible the sleep time
>> before checking for lock might not be enough.
>>
>> -Josh
>>
>>>
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>>
>