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View all threadsAdding 10 MHz permanently to B210?
Hi,
As far as I understand I have to enable external 10 MHz clock source before
the PLL locks onto it and syncs the 40 MHz internal master clock, is this
right? When I look into the circuit diagram I see a switch, choosing between
external clock and GPSDO. What input is selected by default, without
specifying anything? GPSDO?
And is the PLL active all the time, meens, normally running free, and when
it sees a 10 MHz reference it automagically locks?
The idea is, connecting a 0.something ppm TCXO to one of those inputs, to
achieve something better than 10 KHz error at 5.5 GHz without having to turn
this on all the time :)
Ralph, dk5ras.
--
Ralph A. Schmid
Mondstr. 10
90762 Fürth
+49-171-3631223
ralph@schmid.xxx
http://www.bclog.de/
The default state is to use the internal reference clock, unless there's
a GPSDO, in which case, it will select the GPSDO.
Your application can request external clocking during application
initialization.
On 2017-06-29 10:20, Ralph A. Schmid, dk5ras via USRP-users wrote:
Hi,
As far as I understand I have to enable external 10 MHz clock source before
the PLL locks onto it and syncs the 40 MHz internal master clock, is this
right? When I look into the circuit diagram I see a switch, choosing between
external clock and GPSDO. What input is selected by default, without
specifying anything? GPSDO?
And is the PLL active all the time, meens, normally running free, and when
it sees a 10 MHz reference it automagically locks?
The idea is, connecting a 0.something ppm TCXO to one of those inputs, to
achieve something better than 10 KHz error at 5.5 GHz without having to turn
this on all the time :)
Ralph, dk5ras.
--
Ralph A. Schmid
Mondstr. 10
90762 Fürth
+49-171-3631223
ralph@schmid.xxx
http://www.bclog.de/
USRP-users mailing list
USRP-users@lists.ettus.com
http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
Hallo Ralph,
The default source is internal which does not use the GPSDO or external
source. This is the 40 MHz TCXO. I'm not certain which state the switch is
initialized in but it can probabt
If you want to permanently supply a 10 MHz external reference it should be
connected to the external connector. It is required to select the external
reference every time a session is made with the B210, there is no way to
set the external as the default without modifying UHD.
Viele Grüße,
Derek
On Thu, Jun 29, 2017 at 7:20 AM, Ralph A. Schmid, dk5ras via USRP-users <
usrp-users@lists.ettus.com> wrote:
Hi,
As far as I understand I have to enable external 10 MHz clock source before
the PLL locks onto it and syncs the 40 MHz internal master clock, is this
right? When I look into the circuit diagram I see a switch, choosing
between
external clock and GPSDO. What input is selected by default, without
specifying anything? GPSDO?
And is the PLL active all the time, meens, normally running free, and when
it sees a 10 MHz reference it automagically locks?
The idea is, connecting a 0.something ppm TCXO to one of those inputs, to
achieve something better than 10 KHz error at 5.5 GHz without having to
turn
this on all the time :)
Ralph, dk5ras.
--
Ralph A. Schmid
Mondstr. 10
90762 Fürth
+49-171-3631223
ralph@schmid.xxx
http://www.bclog.de/
USRP-users mailing list
USRP-users@lists.ettus.com
http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
Hi Derek,
Modifying something would not matter, I am skilled enough for this, and the thing is out of warranty anyway :)
Remains one basic question, will the PLL lock as soon as it sees 10 MHz on its REF input, or does it need to be enabled by the command that chooses external clock or GPSDO?
Thank you, and with best regards
Ralph.
From: Derek Kozel [mailto:derek.kozel@ettus.com]
Sent: Thursday, June 29, 2017 5:06 PM
To: Ralph A. Schmid, dk5ras
Cc: usrp-users@lists.ettus.com
Subject: Re: [USRP-users] Adding 10 MHz permanently to B210?
Hallo Ralph,
The default source is internal which does not use the GPSDO or external source. This is the 40 MHz TCXO. I'm not certain which state the switch is initialized in but it can probabt
If you want to permanently supply a 10 MHz external reference it should be connected to the external connector. It is required to select the external reference every time a session is made with the B210, there is no way to set the external as the default without modifying UHD.
Viele Grüße,
Derek
On Thu, Jun 29, 2017 at 7:20 AM, Ralph A. Schmid, dk5ras via USRP-users <usrp-users@lists.ettus.com mailto:usrp-users@lists.ettus.com > wrote:
Hi,
As far as I understand I have to enable external 10 MHz clock source before
the PLL locks onto it and syncs the 40 MHz internal master clock, is this
right? When I look into the circuit diagram I see a switch, choosing between
external clock and GPSDO. What input is selected by default, without
specifying anything? GPSDO?
And is the PLL active all the time, meens, normally running free, and when
it sees a 10 MHz reference it automagically locks?
The idea is, connecting a 0.something ppm TCXO to one of those inputs, to
achieve something better than 10 KHz error at 5.5 GHz without having to turn
this on all the time :)
Ralph, dk5ras.
--
Ralph A. Schmid
Mondstr. 10
90762 Fürth
+49-171-3631223
mailto:ralph@schmid.xxx ralph@schmid.xxx
http://www.bclog.de/ http://www.bclog.de/
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