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  • Conventional PSU fan noise

    From Jim GM4DHJ ...@21:1/5 to David Taylor on Sun Aug 23 08:54:06 2020
    On 23/08/2020 05:36, David Taylor wrote:
    On 22/08/2020 22:47, Guy G4DWV 4X1LT wrote:
    Hi,

    My current SMPS is beginning to fail. So I thought I would get a
    conventional PSU. The only thing that I have heard is that they have
    internal fans that can be noisy.

    This https://www.nevadaradio.co.uk/product/nevada-ps-30m/ is what I am
    thinking of getting.

    Thanks in advance for any advice.

    That's switched mode too:

    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    Power Supplies Feature: Switch Mode PSU Brand: Nevada ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

    that is a mistake

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Guy G4DWV 4X1LT@21:1/5 to my reverie and on Sun Aug 23 15:39:40 2020
    On Sun, 23 Aug 2020 05:36:34 +0100, just as I was about to take a
    herb, David Taylor <david-taylor@blueyonder.co.uk.invalid> disturbed
    my reverie and wrote:

    That's switched mode too:
    Phew! Thanks for spotting that!
    --
    73 de Guy G4DWV 4X1LT

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Guy G4DWV 4X1LT@21:1/5 to and on Sun Aug 23 15:44:18 2020
    On Sun, 23 Aug 2020 06:23:48 +0100, just as I was about to take a
    herb, "Jim GM4DHJ ..." <jim.gm4dhj@ntlworld.com> disturbed my reverie
    and wrote:

    says switch mode in the advert but as you say it is not and is very
    heavy with a big transformer......

    Once it is confirmed as a conventional supply, I'll get one. The 40A
    one that you mentioned is only 20 sovs more so will consider it.
    --
    73 de Guy G4DWV 4X1LT

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Jim GM4DHJ ...@21:1/5 to All on Sun Aug 23 17:10:55 2020
    On 23/08/2020 15:39, Guy G4DWV 4X1LT wrote:
    On Sun, 23 Aug 2020 05:36:34 +0100, just as I was about to take a
    herb, David Taylor <david-taylor@blueyonder.co.uk.invalid> disturbed
    my reverie and wrote:

    That's switched mode too:
    Phew! Thanks for spotting that!

    IT'S NOT SWITCHED MODE IT HAS A TRANSFORMER HELLLOOOOOO

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Jim GM4DHJ ...@21:1/5 to All on Sun Aug 23 17:24:06 2020
    On 23/08/2020 15:44, Guy G4DWV 4X1LT wrote:
    On Sun, 23 Aug 2020 06:23:48 +0100, just as I was about to take a
    herb, "Jim GM4DHJ ..." <jim.gm4dhj@ntlworld.com> disturbed my reverie
    and wrote:

    says switch mode in the advert but as you say it is not and is very
    heavy with a big transformer......

    Once it is confirmed as a conventional supply, I'll get one. The 40A
    one that you mentioned is only 20 sovs more so will consider it.

    jeeezus I HAVE ONE...tee hee...does nobody believe ANYTHING I say ?????

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From David Woolley@21:1/5 to All on Mon Aug 24 10:53:55 2020
    On 23/08/2020 17:10, Jim GM4DHJ ... wrote:
    IT'S NOT SWITCHED MODE IT HAS A TRANSFORMER HELLLOOOOOO

    Most switch mode supplies have a transformer, but ferrite rather than
    iron cored, and operating at many kHz. (Some embedded applications,
    like light bulbs, might use live chassis techniques.)

    I'm actually a little surprised that it is still possible to obtain
    linear power supplies on the consumer market, as I don't think they meet
    the CE requirements in terms of distortion of the mains waveform fed
    back into the system. The diodes tend only to conduct for a small part
    of the mains cycle, during which you get big current spikes.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Radio Man@21:1/5 to no-email@tardis.com on Mon Aug 24 09:46:29 2020
    Guy G4DWV 4X1LT <no-email@tardis.com> wrote:
    Hi,

    My current SMPS is beginning to fail. So I thought I would get a
    conventional PSU. The only thing that I have heard is that they have
    internal fans that can be noisy.

    This https://www.nevadaradio.co.uk/product/nevada-ps-30m/ is what I am thinking of getting.

    Thanks in advance for any advice.

    Is there a reason you want a ‘conventional’ PSU?

    While cheap / older switch mode PSUs had a reputation for RF noise etc,
    there are good ones around which are quiet both RF wise and audio wise.
    They also take up less bench space. I like the Samlex ones, if you can
    find them. Footprint is about 8”x8” and maybe 2” high. They have a quiet fan you can just hear. Even with two running I can just detect them but
    there is a mod if this is an issue. One runs 24/7 and doesn’t get warm powering an igate. From memory they are rated at 20A +, I think 25A.
    Nothing detectable on HF, 6m, 4m, 2m or 70 cm RF wise.

    I picked two of mine up at rallies for £20 brand new in boxes. The third
    was a gift.

    I have several linear PSUs but only use them when I need a variable supply
    or on the work bench etc.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From David Woolley@21:1/5 to All on Mon Aug 24 11:09:59 2020
    On 22/08/2020 22:47, Guy G4DWV 4X1LT wrote:
    Thishttps://www.nevadaradio.co.uk/product/nevada-ps-30m/ is what I am thinking of getting.


    The circuit diagram certainly looks to be fully linear as far as
    regulation goes:
    <https://pa0fri.home.xs4all.nl/Diversen/EP925/ep925eng.htm>. Not
    surprisingly, it is brand engineered.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Jim GM4DHJ ...@21:1/5 to David Woolley on Mon Aug 24 12:21:01 2020
    On 24/08/2020 10:53, David Woolley wrote:
    On 23/08/2020 17:10, Jim GM4DHJ ... wrote:
    IT'S NOT SWITCHED MODE IT HAS A TRANSFORMER HELLLOOOOOO

    Most switch mode supplies have a transformer, but ferrite rather than
    iron cored, and operating at many kHz.  (Some embedded applications,
    like light bulbs, might use live chassis techniques.)

    I'm actually a little surprised that it is still possible to obtain
    linear power supplies on the consumer market, as I don't think they meet
    the CE requirements in terms of distortion of the mains waveform fed
    back into the system.  The diodes tend only to conduct for a small part
    of the mains cycle, during which you get big current spikes.
    I don't care I have three of them a 30a daiwa alinco and a nevada
    ......had a switched mode alinco once and it had a tuning knob because
    the noise was not acceptable....

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Ian Jackson@21:1/5 to david@ex.djwhome.demon.invalid on Mon Aug 24 11:48:14 2020
    In message <ri03lo$lj4$1@dont-email.me>, David Woolley <david@ex.djwhome.demon.invalid> writes
    On 22/08/2020 22:47, Guy G4DWV 4X1LT wrote:
    Thishttps://www.nevadaradio.co.uk/product/nevada-ps-30m/ is what I am
    thinking of getting.


    The circuit diagram certainly looks to be fully linear as far as
    regulation goes:
    <https://pa0fri.home.xs4all.nl/Diversen/EP925/ep925eng.htm>. Not >surprisingly, it is brand engineered.

    A nearby amateur owns one of those - but it packed up, and I've been
    tasked with repairing it. The 'beauty' of linear PSUs is that you can
    generally understand how they work.

    The circuit looks simple enough, and the unit delivers volts and amps if
    you uncouple the overload / over-voltage protection part and drive TR6
    base from a separate variable PSU. The resistors and diodes check out
    OK, and with the two parts uncoupled, all the voltages seem 'sensible'.
    I've even changed the ICs (but not the transistors as their voltages
    seem OK). But with the protection part connected, there's virtually no
    output. I've 'put it aside for the moment'!
    --
    Ian

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From David Woolley@21:1/5 to Radio Man on Mon Aug 24 11:20:55 2020
    On 24/08/2020 10:46, Radio Man wrote:
    Is there a reason you want a ‘conventional’ PSU?

    The normal reason for a linear (not conventional) supply is the RF noise
    from the chopping frequency of switching regulators.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Jim GM4 DHJ ...@21:1/5 to David Woolley on Tue Aug 25 07:58:09 2020
    On 24/08/2020 11:09, David Woolley wrote:
    On 22/08/2020 22:47, Guy G4DWV 4X1LT wrote:
    Thishttps://www.nevadaradio.co.uk/product/nevada-ps-30m/  is what I am
    thinking of getting.


    The circuit diagram certainly looks to be fully linear as far as
    regulation goes: <https://pa0fri.home.xs4all.nl/Diversen/EP925/ep925eng.htm>.  Not surprisingly, it is brand engineered.
    the manson ps925 is nothing like the Nevada ps30m

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Jim GM4DHJ ...@21:1/5 to All on Sun May 9 19:29:36 2021
    On 23/08/2020 06:21, Jim GM4DHJ ... wrote:
    On 22/08/2020 22:47, Guy G4DWV 4X1LT wrote:
    Hi,

    My current SMPS is beginning to fail. So I thought I would get a
    conventional PSU. The only thing that I have heard is that they have
    internal fans that can be noisy.

    This https://www.nevadaradio.co.uk/product/nevada-ps-30m/ is what I am
    thinking of getting.

    Thanks in advance for any advice.

    I bought one of those a good few years ago and I find it to be very
    reliable and well made and the fan is not loud at all in fact I can't
    hear it....and the meters light up as well... got it when it was £89 it
    has cost more than £100 at times but £99 is a bargain...go for
    it!...there is a 40a version for a bit more cash.....I know it doesn't
    have a fancy name but I think it is made by a company who knows what
    they are doing....got the nevada PS-O9 from the same manufacturer which
    gives 12a.....all good stuff
    Bought another one and the fan is very noisy...I withdraw my
    cecommendation...

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