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PGXL question

All of testers.  How noisy are the cooling fans?  Especially for those that were in the RTTY contest last weekend.


  • Tim - W4TME
    Tim - W4TME Administrator, FlexRadio Employee admin
    edited January 2018
    That is a relative question.  When operating in a contest or using full duty cycle modes, the amp will require additional cooling of the transistors and this means moving more air across the heatsinks by spinning the fans at a faster rate than when operating lower duty cycle modes.  To some people, the fan noise will not be objectional.  Others may find it excessive.
  • Gordon, ve7on
    Gordon, ve7on Member
    edited June 2020
    I understand air flow is necessary but some amps are quite quiet and some are like a 747.  I am just trying to find out if the PGXL is on the quieter or noisier end of the scale.
  • David Decoons, wo2x
    David Decoons, wo2x Member, Super Elmer Moderator
    edited February 2018
    As Tim said the amp does require air flow. The good thing is the connection from Flex to the amp requires RF cable and Ethernet. You can locate the amp away from the operating position if the fan noise is too loud. Mine is about 6 feet away from the operating position on a lower shelf.

    You can even have it in another room and use the desktop app to control and monitor the amp.

    Solid performer. This is a true full duty cycle amp, not like some other solid state amps that will overheat at full duty cycle.

    Dave wo2x

  • EA4GLI
    EA4GLI Member ✭✭✭
    edited April 2018
  • Ria
    Ria Member ✭✭✭
    edited November 2019
    There are selectable fan modes so you can optimize for quiet or cool. Contest mode can kick up a bit but normal mode is pretty quiet.
  • Rick Hadley - W0FG
    Rick Hadley - W0FG Member ✭✭
    edited January 2018
    I've found normal mode to be very quiet in the amp I've been able to observe.  Contest or intermediate mode is about equivalent to the level generated by the 6500 when the fans kick in at higher temperature...noticeable, but not objectionable.  "Broadcast" mode, on the other hand, sounds like a vacuum cleaner, but that's not something you're likely to need unless you're running something like a full-bore RTTY SO2R contest.
  • AC9S
    AC9S Member ✭✭
    edited June 2020

    Does this mean the fan speed has to be manually selected?  I picked up a used

    KPA500 a couple of weeks ago as a backup  and it ramps fan speed as a function of PA temp.

    Thanks - Keith - AC9S

  • Ria
    Ria Member ✭✭✭
    edited January 2018
    No, it does not. However there are three fan profiles to accommodate different desires for balance between noise and duty cycle. HOWEVER these modes still vary the fan speed with temperature. They just have different thresholds and maximum speeds.

    Normal mode it spins up as the amp gets a bit warmer, to optimize for quiet. Contest mode spins up earlier and keeps it at higher speed longer. Broadcast mode I will not comment on since it is a work in progress but it’s high speed to keep it constantly cool. Ria
  • David Decoons, wo2x
    David Decoons, wo2x Member, Super Elmer Moderator
    edited January 2018
    I will add to what Ria posted. For normal SSB rag chew operating you would most likely want to run normal mode. The more you talk the faster the fans will speed up. The good thing is the amp can be located away from the operating position easily to conserve desk space at the operating position and reduce fan noise. Since it is networked it can be installed across the room, in another room, etc. I am going to install mine with the remote tuner in the garage which is underneath my shack in the spring when I install new shelving. At that time I will run the fans in Contest mode. The amp is a solid performer and is a winner for Flex. Remote operation with control and monitor of the amp is no problem. Dave wo2x

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