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Re: [FT897] fan noise

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  • Geoff
    I don t think the pics made it through. What about a simple thermostat switch? or are they not accurate enough.. eg
    Message 1 of 13 , Apr 5 5:44 AM
    • 0 Attachment
      I don't think the pics made it through.

      What about a simple thermostat switch? or are they not accurate enough..

      eg http://jaycar.com.au/productView.asp?ID=ST3831

      Geoff VK2MIA


      On 5/04/2012 6:22 AM, Minto Witteveen wrote:
      > Hi Philippe,
      >
      > Here are two photo’s. (Hope they stay inserted by the mailer…)
      > The circuit can be seen top left on the first photo. It includes a 78L05, an 18F1330 and a fet. Plus a jumper for programming and a bus for attaching an rs232 board (used for testing and reporting actual measured temp, these test led me to choose 40 and 45 degrees as lower and upper temp).
      > The LM335 can be seen mid-right side. It fits snugly between the heatsink and the PCB. A series resistor and a decoupling ceramic can also be seen.
      >
      > The second photo shows the +12 volts power feed I got from the underside of the rig. (green and blue wires)
      >
      > If you like I can send you an email with the (project) code for the 1330, written in hitech C18.
      >
      > Regards,
      > Minto pa3bca
      >
      >
      >
      >
      >
      >
      >
      >
      >
      > --------------------------------------------------------------------------
      > Ceterum censeo Carthaginem delendam esse
      > -----Original Message-----
      > From: Philippe ON4VP
      > Sent: Wednesday, April 04, 2012 21:21
      > To: FT897@yahoogroups.com
      > Subject: Re: [FT897] fan noise
      >
      > Now that is what I'm talking about.
      > Great Job Minto.
      >
      > Would it be possible to provide pictures of the place where you installed
      > it.
      > I'd like to do exactly the same modification.
      >
      > Thanks a lot for sharing.
      > 73, ON4VP
      >
      > Op 4 april 2012 18:51 schreef Minto Witteveen
      > <minto.witteveen@...>het volgende:
      >
      >> **
      >>
      >>
      >> The 897’s fans are indeed quite (annoyingly) loud – and all 897’s I have
      >> seen and heard make the same noise. The noise is caused by rather small
      >> fans running at high rpm in an enclosed environment (not optimized for
      >> least noise). It’s just moving the air.
      >> I find it extremely unlikely that oiling the bearings of the fans will
      >> solve the noise problem. If the majority of the noise would be caused by
      >> the bearings you’d have a bigger problem seeing how much noise is already
      >> generated by the moving air….. Besides how many hours would the fans have
      >> on their odometers?
      >>
      >> The noise annoyed me too. So I did what I think Yaesu should have done: I
      >> installed a small circuit that activates the fans only when necessary. This
      >> means not every time the PTT is pressed (and stopped after release of the
      >> PTT regardless of the actual temperature of the rig..)
      >> Now when I use the rig for short FM transmissions or (longer) SSB the rig
      >> stays silent. The fans only come on after prolonged TX. What a relief J
      >> The circuit consist of a 18f1330 Microchip PIC, an LM335 analog temp
      >> sensor mounted on the internal heat sink near the PA, and a logic-level fet
      >> to switch the fans directly from +12 volt.
      >> I have the fans switch on when the temp of the heatsink exceeds 45 degrees
      >> (celcius!) and switch off below 40 degrees.
      >> The 1330 is a bit overkill but it is what I had laying around at the time.
      >> Works perfect for me…
      >>
      >> Regards,
      >> Minto pa3bca
      >
      > [Non-text portions of this message have been removed]
      >
      >
      >
      > ------------------------------------
      >
      > Yahoo! Groups Links
      >
      >
      >
    • Minto Witteveen
      Yes Philippe already told me the pics got lost. For those who are interested, they can be found Here: http://pa3bca.pa3bca.nl/tmp/IMG_4946.jpg And here:
      Message 2 of 13 , Apr 5 9:06 AM
      • 0 Attachment
        Yes Philippe already told me the pics got lost. For those who are
        interested, they can be found
        Here: http://pa3bca.pa3bca.nl/tmp/IMG_4946.jpg
        And here: http://pa3bca.pa3bca.nl/tmp/IMG_4950.jpg

        A simple thermostat is probably good enough. 50 degrees is still acceptable
        I think. The reason why I used the 1330 is simple. My annoyance threshold
        was exceeded on a Saturday evening, and I wanted a fix immediately. Therefor
        the 1330 and the LM335 I had laying around. It also gave me the option to
        experiment with temperature thresholds. And as far as I know these
        thermostats have almost no hysteresis so they tend to switch on/off around
        50 degrees more than would be acceptable by my annoyance threshold :-)

        Regards,
        Minto pa3bca




        --------------------------------------------------------------------------
        Ceterum censeo Carthaginem delendam esse
        -----Original Message-----
        From: Geoff
        Sent: Thursday, April 05, 2012 14:44
        To: FT897@yahoogroups.com
        Cc: Minto Witteveen
        Subject: Re: [FT897] fan noise

        I don't think the pics made it through.

        What about a simple thermostat switch? or are they not accurate enough..

        eg http://jaycar.com.au/productView.asp?ID=ST3831

        Geoff VK2MIA


        On 5/04/2012 6:22 AM, Minto Witteveen wrote:
        > Hi Philippe,
        >
        > Here are two photo’s. (Hope they stay inserted by the mailer…)
        > The circuit can be seen top left on the first photo. It includes a 78L05,
        > an 18F1330 and a fet. Plus a jumper for programming and a bus for
        > attaching an rs232 board (used for testing and reporting actual measured
        > temp, these test led me to choose 40 and 45 degrees as lower and upper
        > temp).
        > The LM335 can be seen mid-right side. It fits snugly between the heatsink
        > and the PCB. A series resistor and a decoupling ceramic can also be seen.
        >
        > The second photo shows the +12 volts power feed I got from the underside
        > of the rig. (green and blue wires)
        >
        > If you like I can send you an email with the (project) code for the 1330,
        > written in hitech C18.
        >
        > Regards,
        > Minto pa3bca
        >
        >
        >
        >
        >
        >
        >
        >
        >
        > --------------------------------------------------------------------------
        > Ceterum censeo Carthaginem delendam esse
        > -----Original Message-----
        > From: Philippe ON4VP
        > Sent: Wednesday, April 04, 2012 21:21
        > To: FT897@yahoogroups.com
        > Subject: Re: [FT897] fan noise
        >
        > Now that is what I'm talking about.
        > Great Job Minto.
        >
        > Would it be possible to provide pictures of the place where you installed
        > it.
        > I'd like to do exactly the same modification.
        >
        > Thanks a lot for sharing.
        > 73, ON4VP
        >
        > Op 4 april 2012 18:51 schreef Minto Witteveen
        > <minto.witteveen@...>het volgende:
        >
        >> **
        >>
        >>
        >> The 897’s fans are indeed quite (annoyingly) loud – and all 897’s I have
        >> seen and heard make the same noise. The noise is caused by rather small
        >> fans running at high rpm in an enclosed environment (not optimized for
        >> least noise). It’s just moving the air.
        >> I find it extremely unlikely that oiling the bearings of the fans will
        >> solve the noise problem. If the majority of the noise would be caused by
        >> the bearings you’d have a bigger problem seeing how much noise is already
        >> generated by the moving air….. Besides how many hours would the fans have
        >> on their odometers?
        >>
        >> The noise annoyed me too. So I did what I think Yaesu should have done: I
        >> installed a small circuit that activates the fans only when necessary.
        >> This
        >> means not every time the PTT is pressed (and stopped after release of the
        >> PTT regardless of the actual temperature of the rig..)
        >> Now when I use the rig for short FM transmissions or (longer) SSB the rig
        >> stays silent. The fans only come on after prolonged TX. What a relief J
        >> The circuit consist of a 18f1330 Microchip PIC, an LM335 analog temp
        >> sensor mounted on the internal heat sink near the PA, and a logic-level
        >> fet
        >> to switch the fans directly from +12 volt.
        >> I have the fans switch on when the temp of the heatsink exceeds 45
        >> degrees
        >> (celcius!) and switch off below 40 degrees.
        >> The 1330 is a bit overkill but it is what I had laying around at the
        >> time.
        >> Works perfect for me…
        >>
        >> Regards,
        >> Minto pa3bca
        >
        > [Non-text portions of this message have been removed]
        >
        >
        >
        > ------------------------------------
        >
        > Yahoo! Groups Links
        >
        >
        >
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