Water cooling; was KPA1500 Fan Noise

[John Simmons]

The Russian group, eb104, produces LDMOS water cooled amps. You can see
them on their YouTube channel. The amps are much quieter than the
KPA1500 but not as compact.

73,
-John NI0K

> Clay Autery <mailto:[hidden email]>
> Sunday, June 03, 2018 1:08 PM
> "Water cooling" has come a LONG way from the days back in the 90s when
> we were machining out own water blocks from aluminum and copper, and
> trying to construct flow loops that didn't leak, find suitable
> radiators, etc.
>
> But I don't think there are any current CPU/GPU coolers on the market
> that would touch the heat rejection requirements of the combined LDMOS
> modules, assuming you could find a model that could be adapted, and
> somehow managed to find a way to get it attached....  You'd ALMOST
> HAVE to cool the copper heat spreader, since the LDMOS are I suspect
> soldered to it.  Don't know if the heat spreader is soldered or
> mechanically attached to the heat sink..  It is possible that you
> could gang multiple large OTS CPU coolers onto the heat spreader in
> place of the massive heatsink.
>
> Then you'd need to figure out what you were going to do with the 1-
> "n" number of sets of hoses and radiators.... and 1-3 times n number
> of radiators in very large fans.
>
> And THEN, remember that there are other thermal loads inside the
> chassis...  You'll still need to provided some airflow to those loads,
> so you'll still need case fans.
>
> Certainly and interesting and intriguing project for someone deep of
> pockets and most grande of huevos....  but not a trivial task certainly.
> I personally would not risk my $6k amp to do it... If I had one.  :(
>
> 73,
>
> ______________________
> Clay Autery, KY5G
> [phone]
>
>
>
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> Drew AF2Z <mailto:[hidden email]>
> Sunday, June 03, 2018 8:11 AM
> There are liquid cooling systems available for CPUs and graphics
> cards, used by gamers and overclockers. Have no idea how this would
> compare to cooling a 1500 watt RF power amplifier but probably more
> analogous than an airplane engine.
>
> 73,
> Drew
> AF2Z
>
>
>
>
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> Dauer, Edward <mailto:[hidden email]>
> Saturday, June 02, 2018 4:09 PM
> I have been following this thread with interest because I have a
> KPA1500 on order, and I have very limited flexibility as to where the
> RF deck can go compared to where I will have to sit.
>
> Don's video was very well done and a great help in understanding the
> realities.
>
> I know zero about thermodynamics, and so wanted only to say thanks to
> everyone who is contributing ideas, and to make but two comments.
>
> First, as to water cooling, I suspect it would be a huge weight
> penalty to get the cooling fluid everywhere it needs to be. So far as
> I know there is only one reciprocating engine made for aircraft that
> has a water jacket. (There might be others nowadays - I haven't owned
> an airplane for some years.) The reasons others don't are reliability,
> safety, complexity, and - mostly - weight. Second, isn't this largely
> a contest-operating issue? I believe we are still governed by the rule
> that we may use only that amount of power necessary for the
> communication. I contest too, so I'll face the problem on those
> occasions, but not for casual ragchews. I plan to make some graphs of
> when in terms of time, power, mode and band the fans on mine kick up a
> notch, and use it as a general operating guideline if I need to.
>
> Ted, KN1CBR
>
>
>
> Date: Sat, 2 Jun 2018 08:48:46 -0600
> From: Don Butler <[hidden email]>
> To: Paul Baldock <[hidden email]>, "[hidden email]"
> <[hidden email]>
> Subject: Re: [Elecraft] KPA1500 Fan Noise Video posted
> Message-ID: <[hidden email]>
> Content-Type: text/plain; charset="utf-8"
>
> Paul ?. The PS noise is minimal from my point of view. The power
> supply fans do run continuously while the amp is switched on ?. You
> can hear the PS fans at the beginning and end of the video when the
> fan speed is set at ?0? .. all you?re hearing at that time is the PS
> fan ? at power down right at the end you can hear when the PS fans stop.
>
> Don, N5LZ
>
>
>
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