• PLLs and phase noise

    From Cursitor Doom@21:1/5 to All on Sun Jul 21 17:53:38 2024
    Gentlemen,

    Okay, I know this is a stupid question, but just a rough idea would
    suffice. Given a typical RF PLL, how much phase noise would prevent
    the thing from locking?

    CD.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Jeroen Belleman@21:1/5 to Cursitor Doom on Sun Jul 21 19:48:35 2024
    On 7/21/24 18:53, Cursitor Doom wrote:
    Gentlemen,

    Okay, I know this is a stupid question, but just a rough idea would
    suffice. Given a typical RF PLL, how much phase noise would prevent
    the thing from locking?

    CD.

    I'd love to give you a fair answer, but as it stands, the question
    is far too vague. PLLs can be very good at detecting a signal buried
    in noise, but the devil is in the details. What are you trying to do?

    Jeroen Belleman

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Cursitor Doom@21:1/5 to jeroen@nospam.please on Sun Jul 21 19:16:13 2024
    On Sun, 21 Jul 2024 19:48:35 +0200, Jeroen Belleman
    <jeroen@nospam.please> wrote:

    On 7/21/24 18:53, Cursitor Doom wrote:
    Gentlemen,

    Okay, I know this is a stupid question, but just a rough idea would
    suffice. Given a typical RF PLL, how much phase noise would prevent
    the thing from locking?

    CD.

    I'd love to give you a fair answer, but as it stands, the question
    is far too vague. PLLs can be very good at detecting a signal buried
    in noise, but the devil is in the details. What are you trying to do?


    Fix my spectrum analyzer. It's a complex beast and it has a YIG-tuned oscillator stage which is out of lock. its IF is all over the place;
    not just jittery but out of band, and I have to find out why.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Jeroen Belleman@21:1/5 to Cursitor Doom on Sun Jul 21 23:01:03 2024
    On 7/21/24 20:16, Cursitor Doom wrote:
    On Sun, 21 Jul 2024 19:48:35 +0200, Jeroen Belleman
    <jeroen@nospam.please> wrote:

    On 7/21/24 18:53, Cursitor Doom wrote:
    Gentlemen,

    Okay, I know this is a stupid question, but just a rough idea would
    suffice. Given a typical RF PLL, how much phase noise would prevent
    the thing from locking?

    CD.

    I'd love to give you a fair answer, but as it stands, the question
    is far too vague. PLLs can be very good at detecting a signal buried
    in noise, but the devil is in the details. What are you trying to do?


    Fix my spectrum analyzer. It's a complex beast and it has a YIG-tuned oscillator stage which is out of lock. its IF is all over the place;
    not just jittery but out of band, and I have to find out why.

    I suppose the first thing to look at would be the power supplies
    of the relevant section. Can you also get a look at the tuning
    voltage of the YIG?

    Jeroen Belleman

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Cursitor Doom@21:1/5 to All on Sun Jul 21 22:57:09 2024
    On Sun, 21 Jul 2024 23:33:55 +0200, Gerhard Hoffmann <dk4xp@arcor.de>
    wrote:

    Am 21.07.24 um 23:01 schrieb Jeroen Belleman:

    I suppose the first thing to look at would be the power supplies
    of the relevant section. Can you also get a look at the tuning
    voltage of the YIG?

    current!

    Ideally the current is what's relevant here. It should be between 50
    and 150mA. However, measuring that is a little bit tricky, so they
    provide a test point for the voltage instead, and that does indicate
    what appears to be the correct behaviour. But that's just an aside,
    since the problem lies upstream from the coil driver.


    Is is also in the US, that the news volume has dropped to nearly nothing?

    Gerhard

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Jeroen Belleman@21:1/5 to Gerhard Hoffmann on Sun Jul 21 23:55:38 2024
    On 7/21/24 23:33, Gerhard Hoffmann wrote:
    Am 21.07.24 um 23:01 schrieb Jeroen Belleman:

    I suppose the first thing to look at would be the power supplies
    of the relevant section. Can you also get a look at the tuning
    voltage of the YIG?
    current!

    OK, sure.


    Is is also in the US, that the news volume has dropped to nearly nothing?

    Gerhard


    CrowdStrike struck down the crowd of MS-Windows servers? Let this
    be a lesson.

    Jeroen Belleman

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Gerhard Hoffmann@21:1/5 to All on Sun Jul 21 23:33:55 2024
    Am 21.07.24 um 23:01 schrieb Jeroen Belleman:

    I suppose the first thing to look at would be the power supplies
    of the relevant section. Can you also get a look at the tuning
    voltage of the YIG?
    current!

    Is is also in the US, that the news volume has dropped to nearly nothing?

    Gerhard

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)