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KPA1500 Power Supply Fan Noise

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KPA1500 Power Supply Fan Noise

More broadly, has there been any progress on reducing the piercing power supply fan noise on the KPA1500 when only using it as a tuner or an antenna switch? I complained about this a year ago, and I find it completely unacceptable. No set of noise-reducing headphones that I have tried works well enough to make the noise tolerable. I've tried moving the PS deck around with minimal improvement. This just doesn't seem to fit Elecraft's philosophy of a quiet operating environment. Why do these fans have to operate at full throttle when there is minimal current draw from the rf deck? Why do these fans create such a piercing high-pitched note?
If there is no response from Elecraft, what have other ops done--short of moving the PS into an adjoining room--to mitigate the scream?
Thanks,
73 Eric WD6DBM

Sent from Yahoo Mail on Android
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Doug Turnbull

Re: KPA1500 Power Supply Fan Noise

Eric, I do not understand your problem with the PS and audible noise. The larger fans in my KPA1500 are quiet. Any noise is at low freq. The RF deck does produce noise and I wish it did not. My Sony noise cancelling phones handle this noise well. Maybe your PS has faulty fans. Are the bearings okay? Please do not get annoyed with me but this is my experience.I suppose cooling junction temperatures low takes a lot of air. My Acom 2000A tube amp is much quieter.73 Doug EI2CNSent from my Samsung Galaxy smartphone.
-------- Original message --------From: eric norris via Elecraft <[hidden email]> Date: 11/06/2019 00:57 (GMT+00:00) To: [hidden email], [hidden email], Elecraft Reflector <[hidden email]> Subject: [Elecraft] KPA1500 Power Supply Fan Noise More broadly, has there been any progress on reducing the piercing power supply fan noise on the KPA1500 when only using it as a tuner or an antenna switch? I complained about this a year ago, and I find it completely unacceptable. No set of noise-reducing headphones that I have tried works well enough to make the noise tolerable. I've tried moving the PS deck around with minimal improvement. This just doesn't seem to fit Elecraft's philosophy of a quiet operating environment. Why do these fans have to operate at full throttle when there is minimal current draw from the rf deck? Why do these fans create such a piercing high-pitched note? If there is no response from Elecraft, what have other ops done--short of moving the PS into an adjoining room--to mitigate the scream?Thanks,73 Eric WD6DBMSent from Yahoo Mail on Android______________________________________________________________Elecraft mailing listHome: http://mailman.qth.net/mailman/listinfo/elecraftHelp: http://mailman.qth.net/mmfaq.htmPost: mailto:[hidden email] list hosted by: http://www.qsl.netPlease help support this email list: http://www.qsl.net/donate.htmlMessage delivered to [hidden email]
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Jim Brown-10

Re: KPA1500 Power Supply Fan Noise

On 6/11/2019 12:20 AM, turnbull wrote:
> Eric, I do not understand your problem with the PS and audible noise. The larger fans in my KPA1500 are quiet. Any noise is at low freq.

Do you work keydown modes at high duty cycles, like RTTY contesting or
WSJT-X modes where high power is needed (6M, 160M, for example)? If you
do a lot of meteor scatter or FT8 or moonbounce, especially on 6M where
the efficiency is lowest, it doesn't take long for the fans to scream.
And that's because they are small, which they must be to fit in the
height dimension of the power amp.

73, Jim K9YC

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Peter Hall

Re: KPA1500 Power Supply Fan Noise

In reply to this post by Elecraft mailing list

Hello Eric

There's no doubt that a KPA1500 physical installation needs some careful attention to the noise aspect. That said, I'm a bit surprised by your problem with the PSU fan. I can certainly hear mine but, overall, the noise is entirely dominated by the RF deck fans. I've located the PSU under my operating desk, which is made of a dense particleboard material. The RF deck sits alongside my TS-890S transceiver on the desk. I can hear the PSU fan if I put my head below desk level but, even then, I don't find the fan to be particularly high-pitched in its acoustic output. Could you possibly have a faulty fan (maybe excess nearing noise)?

On the other hand, I do find the RF deck fans test my patience a bit, especially since the last round of major firmware updates which start the cooling at a lower heatsink temperature. That probably works well in a high-output environment, where it no doubt delays the onset of heat soaking. But when the amplifier "loafs" in a low power, low duty cycle environment as it does in some of my applications. it just starts the noise prematurely. It'd be great to see something like an "80m rag-chew" option for those times!

73, Peter (VK6HP).

-----Original Message-----
From: [hidden email] <[hidden email]> On Behalf Of eric norris via Elecraft
Sent: Tuesday, 11 June 2019 7:57 AM
To: [hidden email]; [hidden email]; Elecraft Reflector <[hidden email]>
Subject: [Elecraft] KPA1500 Power Supply Fan Noise

More broadly, has there been any progress on reducing the piercing power supply fan noise on the KPA1500 when only using it as a tuner or an antenna switch? I complained about this a year ago, and I find it completely unacceptable. No set of noise-reducing headphones that I have tried works well enough to make the noise tolerable. I've tried moving the PS deck around with minimal improvement. This just doesn't seem to fit Elecraft's philosophy of a quiet operating environment. Why do these fans have to operate at full throttle when there is minimal current draw from the rf deck? Why do these fans create such a piercing high-pitched note? If there is no response from Elecraft, what have other ops done--short of moving the PS into an adjoining room--to mitigate the scream?
Thanks,
73 Eric WD6DBM

Sent from Yahoo Mail on Android
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Eric Norris-2

Re: KPA1500 Power Supply Fan Noise

Apparently I was not clear enough in my message. It is the PSU fan noise
that is deafening, not the RF deck. Like Peter, my PSU sits on the floor
underneath a wooden operating desk that holds the rest of the K-line. The
noise from the PSU is high-pitched and piercing. The only thing I can
liken it to is a four-rotor Mazda prototype IMSA GTP race car from the
early 90s. Brain-piercing, tear-your-hair-out, heard-from-every
room-in-the-house louder than hell, and has been so since the day it
darkened my doorway--with the RF deck at idle.

73 Eric WD6DBM

On Tue, Jun 11, 2019, 12:54 AM Peter Hall <[hidden email]> wrote:

> Hello Eric
>
> There's no doubt that a KPA1500 physical installation needs some careful
> attention to the noise aspect. That said, I'm a bit surprised by your
> problem with the PSU fan. I can certainly hear mine but, overall, the
> noise is entirely dominated by the RF deck fans. I've located the PSU
> under my operating desk, which is made of a dense particleboard material.
> The RF deck sits alongside my TS-890S transceiver on the desk. I can hear
> the PSU fan if I put my head below desk level but, even then, I don't find
> the fan to be particularly high-pitched in its acoustic output. Could you
> possibly have a faulty fan (maybe excess nearing noise)?
>
> On the other hand, I do find the RF deck fans test my patience a bit,
> especially since the last round of major firmware updates which start the
> cooling at a lower heatsink temperature. That probably works well in a
> high-output environment, where it no doubt delays the onset of heat
> soaking. But when the amplifier "loafs" in a low power, low duty cycle
> environment as it does in some of my applications. it just starts the noise
> prematurely. It'd be great to see something like an "80m rag-chew" option
> for those times!
>
> 73, Peter (VK6HP).
>
> -----Original Message-----
> From: [hidden email] <[hidden email]>
> On Behalf Of eric norris via Elecraft
> Sent: Tuesday, 11 June 2019 7:57 AM
> To: [hidden email]; [hidden email]; Elecraft Reflector <
> [hidden email]>
> Subject: [Elecraft] KPA1500 Power Supply Fan Noise
>
> More broadly, has there been any progress on reducing the piercing power
> supply fan noise on the KPA1500 when only using it as a tuner or an antenna
> switch? I complained about this a year ago, and I find it completely
> unacceptable. No set of noise-reducing headphones that I have tried works
> well enough to make the noise tolerable. I've tried moving the PS deck
> around with minimal improvement. This just doesn't seem to fit Elecraft's
> philosophy of a quiet operating environment. Why do these fans have to
> operate at full throttle when there is minimal current draw from the rf
> deck? Why do these fans create such a piercing high-pitched note? If there
> is no response from Elecraft, what have other ops done--short of moving the
> PS into an adjoining room--to mitigate the scream?
> Thanks,
> 73 Eric WD6DBM
>
> Sent from Yahoo Mail on Android
> ______________________________________________________________
> Elecraft mailing list
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John Langdon

Re: KPA1500 Power Supply Fan Noise

Eric,

My KPA1500 RF deck is mounted on a high shelf, and the power supply is on low shelf below the desk. I have the fan speed on the RF deck set to 2 as a minimum. I almost never notice the PS fans, when I hear noise it is the RF deck. During the ARRL DX CW the fans reached 4 and it was loud enough to need headphones, in most operation it is not. The PS noise you are describing does not seem normal to me. Can you make a video/audio recording and post it on the web somewhere?

73 John N5CQ

-----Original Message-----
From: [hidden email] <[hidden email]> On Behalf Of Eric Norris
Sent: Tuesday, June 11, 2019 3:47 AM
To: Peter Hall <[hidden email]>
Cc: elecraft@mailman qth. net <[hidden email]>
Subject: Re: [Elecraft] KPA1500 Power Supply Fan Noise

Apparently I was not clear enough in my message. It is the PSU fan noise that is deafening, not the RF deck. Like Peter, my PSU sits on the floor underneath a wooden operating desk that holds the rest of the K-line. The noise from the PSU is high-pitched and piercing. The only thing I can liken it to is a four-rotor Mazda prototype IMSA GTP race car from the early 90s. Brain-piercing, tear-your-hair-out, heard-from-every room-in-the-house louder than hell, and has been so since the day it darkened my doorway--with the RF deck at idle.

73 Eric WD6DBM

On Tue, Jun 11, 2019, 12:54 AM Peter Hall <[hidden email]> wrote:

> Hello Eric
>
> There's no doubt that a KPA1500 physical installation needs some
> careful attention to the noise aspect. That said, I'm a bit surprised
> by your problem with the PSU fan. I can certainly hear mine but,
> overall, the noise is entirely dominated by the RF deck fans. I've
> located the PSU under my operating desk, which is made of a dense particleboard material.
> The RF deck sits alongside my TS-890S transceiver on the desk. I can hear
> the PSU fan if I put my head below desk level but, even then, I don't
> find the fan to be particularly high-pitched in its acoustic output.
> Could you possibly have a faulty fan (maybe excess nearing noise)?
>
> On the other hand, I do find the RF deck fans test my patience a bit,
> especially since the last round of major firmware updates which start
> the cooling at a lower heatsink temperature. That probably works well
> in a high-output environment, where it no doubt delays the onset of
> heat soaking. But when the amplifier "loafs" in a low power, low duty
> cycle environment as it does in some of my applications. it just
> starts the noise prematurely. It'd be great to see something like an
> "80m rag-chew" option for those times!
>
> 73, Peter (VK6HP).
>
> -----Original Message-----
> From: [hidden email]
> <[hidden email]>
> On Behalf Of eric norris via Elecraft
> Sent: Tuesday, 11 June 2019 7:57 AM
> To: [hidden email]; [hidden email]; Elecraft Reflector <
> [hidden email]>
> Subject: [Elecraft] KPA1500 Power Supply Fan Noise
>
> More broadly, has there been any progress on reducing the piercing
> power supply fan noise on the KPA1500 when only using it as a tuner or
> an antenna switch? I complained about this a year ago, and I find it
> completely unacceptable. No set of noise-reducing headphones that I
> have tried works well enough to make the noise tolerable. I've tried
> moving the PS deck around with minimal improvement. This just doesn't
> seem to fit Elecraft's philosophy of a quiet operating environment.
> Why do these fans have to operate at full throttle when there is
> minimal current draw from the rf deck? Why do these fans create such
> a piercing high-pitched note? If there is no response from Elecraft,
> what have other ops done--short of moving the PS into an adjoining room--to mitigate the scream?
> Thanks,
> 73 Eric WD6DBM
>
> Sent from Yahoo Mail on Android
> ______________________________________________________________
> Elecraft mailing list
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Roy Koeppe

Re: KPA1500 Power Supply Fan Noise

In reply to this post by Eric Norris-2

Eric -- this is not at all normal! My PSU is quiet...hardly hear it from
under the table. I understand Elecraft changed to much quieter fans maybe
two years ago. But even so, perhaps the voltage to your fans has soared way
to high? I haven't looked at the circuit driving them. Maybe lost
regulation, etc.

73, Roy K6XK

Apparently I was not clear enough in my message. It is the PSU fan noise
that is deafening, not the RF deck. Like Peter, my PSU sits on the floor
underneath a wooden operating desk that holds the rest of the K-line. The
noise from the PSU is high-pitched and piercing. The only thing I can
liken it to is a four-rotor Mazda prototype IMSA GTP race car from the
early 90s. Brain-piercing, tear-your-hair-out, heard-from-every
room-in-the-house louder than hell, and has been so since the day it
darkened my doorway--with the RF deck at idle.

73 Eric WD6DBM

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Larry (K8UT)

Re: KPA1500 Power Supply Fan Noise

In reply to this post by Elecraft mailing list

Eric,

My shack is a relatively quiet operating environment, but declaring
something as quiet or noisy is always somewhat subjective. The fans in
my PSU are pretty quiet, but nevertheless the KPA1500 PSU is
remote-installed in a closet in my shack.

I am absolutely no "audio" guy, but years ago installed a free, cheap &
dirty noise level meter app on my android phone called "Sound Meter." I
use it to complain to restaurant managers that the blaring music in
their establishments is too loud for casual conversation, demanding that
it be turned down.

With the KPA1500 turned off and phone situated 3 feet from the power
supply, the noise level in that closet is 28 DB. Turning on the
amplifier raises the noise level by 12 DB to 40 DB - a 12 DB difference.
Not much difference, and certainly not the "piercing power supply fan
noise" you describe.

-larry (K8UT)

------ Original Message ------
From: "eric norris via Elecraft" <[hidden email]>
To: "[hidden email]" <[hidden email]>; "[hidden email]"
<[hidden email]>; "Elecraft Reflector" <[hidden email]>
Sent: 2019-06-10 19:57:02
Subject: [Elecraft] KPA1500 Power Supply Fan Noise

>More broadly, has there been any progress on reducing the piercing power supply fan noise on the KPA1500 when only using it as a tuner or an antenna switch? I complained about this a year ago, and I find it completely unacceptable. No set of noise-reducing headphones that I have tried works well enough to make the noise tolerable. I've tried moving the PS deck around with minimal improvement. This just doesn't seem to fit Elecraft's philosophy of a quiet operating environment. Why do these fans have to operate at full throttle when there is minimal current draw from the rf deck? Why do these fans create such a piercing high-pitched note?
>If there is no response from Elecraft, what have other ops done--short of moving the PS into an adjoining room--to mitigate the scream?
>Thanks,
>73 Eric WD6DBM
>
>Sent from Yahoo Mail on Android
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Elecraft mailing list

Re: KPA1500 Power Supply Fan Noise

In reply to this post by Roy Koeppe

My KPA1500 s/n 156 had such a problem with PS audible noise.?? It was
fixed with two mods available from Elecraft, one a new LED board and
another with a resistor addition to the MeanWell power supply output??
The latter was probably not associated with noise but it's an addition
that was not on my #156.

73,
Dan -- N3ND

On 6/11/2019 7:51 AM, Roy Koeppe wrote:

> Eric -- this is not at all normal! My PSU is quiet...hardly hear it
> from under the table. I understand Elecraft changed to much quieter
> fans maybe two years ago. But even so, perhaps the voltage to your
> fans has soared way to high? I haven't looked at the circuit driving
> them. Maybe lost regulation, etc.
>
> 73,???? Roy?????? K6XK
>
>
> Apparently I was not clear enough in my message.?? It is the PSU fan noise
> that is deafening, not the RF deck.?? Like Peter, my PSU sits on the floor
> underneath a wooden operating desk that holds the rest of the K-line.??
> The
> noise from the PSU is high-pitched and piercing.?? The only thing I can
> liken it to is a four-rotor Mazda prototype IMSA GTP race car from the
> early 90s.?? Brain-piercing, tear-your-hair-out, heard-from-every
> room-in-the-house louder than hell, and has been so since the day it
> darkened my doorway--with the RF deck at idle.
>
> 73 Eric WD6DBM
>
>
>
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Richard Thorne-4

Re: KPA1500 Power Supply Fan Noise

Michael Walker

Re: KPA1500 Power Supply Fan Noise

How loud is the noise?

Can you measure it at all? There are many smart phone apps that are really
good.

I compared my iPhone to a bench standard and it was off by less 0.5db at
most frequencies. Pretty impressive actually.

Mike va3mw

On Tue, Jun 11, 2019 at 9:49 AM Richard Thorne <[hidden email]> wrote:

>
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N4ZR

Re: KPA1500 Power Supply Fan Noise

In reply to this post by Elecraft mailing list

And my SN 502 is perfectly acceptable, even with the stock fan-ware (is
that a word?)

73, Pete N4ZR
Check out the Reverse Beacon Network
at <http://reversebeacon.net>, now
spotting RTTY activity worldwide.
For spots, please use your favorite
"retail" DX cluster.

On 6/11/2019 9:22 AM, Dan Atchison via Elecraft wrote:

> My KPA1500 s/n 156 had such a problem with PS audible noise.?? It was
> fixed with two mods available from Elecraft, one a new LED board and
> another with a resistor addition to the MeanWell power supply output??
> The latter was probably not associated with noise but it's an addition
> that was not on my #156.
>
> 73,
> Dan -- N3ND
>
> On 6/11/2019 7:51 AM, Roy Koeppe wrote:
>> Eric -- this is not at all normal! My PSU is quiet...hardly hear it
>> from under the table. I understand Elecraft changed to much quieter
>> fans maybe two years ago. But even so, perhaps the voltage to your
>> fans has soared way to high? I haven't looked at the circuit driving
>> them. Maybe lost regulation, etc.
>>
>> 73,???? Roy?????? K6XK
>>
>>
>> Apparently I was not clear enough in my message.?? It is the PSU fan
>> noise
>> that is deafening, not the RF deck.?? Like Peter, my PSU sits on the
>> floor
>> underneath a wooden operating desk that holds the rest of the
>> K-line.?? The
>> noise from the PSU is high-pitched and piercing.?? The only thing I can
>> liken it to is a four-rotor Mazda prototype IMSA GTP race car from the
>> early 90s.?? Brain-piercing, tear-your-hair-out, heard-from-every
>> room-in-the-house louder than hell, and has been so since the day it
>> darkened my doorway--with the RF deck at idle.
>>
>> 73 Eric WD6DBM
>>
>>
>>
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:[hidden email]
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>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>> Message delivered to [hidden email]
>
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K9MA

Re: KPA1500 Power Supply Fan Noise

In reply to this post by Elecraft mailing list

I suspect the reason the power supply fans run at constant speed is that
they are part of the Meanwell power supply, and beyond Elecraft's
control due to warranty issues, etc. I certainly can't fault Elecraft
for using that power supply, as it's cost effective and probably helped
get the KPA1500 on the market more quickly. We can hope that perhaps
some day Meanwell will switch to a temperature controlled fan.

I don't find mine particularly loud, as the RF deck fans drown them out
even at their lower speeds. Even the K3 fans will drown it out when I'm
running in a CW contest. I use some very good passive headphones,
however. I don't think it's realistic to expect to be able to operate
with an amplifier in the shack without headphones. However, the KPA1500
is fully capable of remote operation, so you could put it in the next room.

73,
Scott K9MA

On 6/10/2019 18:57, eric norris via Elecraft wrote:

> More broadly, has there been any progress on reducing the piercing power supply fan noise on the KPA1500 when only using it as a tuner or an antenna switch? I complained about this a year ago, and I find it completely unacceptable. No set of noise-reducing headphones that I have tried works well enough to make the noise tolerable. I've tried moving the PS deck around with minimal improvement. This just doesn't seem to fit Elecraft's philosophy of a quiet operating environment. Why do these fans have to operate at full throttle when there is minimal current draw from the rf deck? Why do these fans create such a piercing high-pitched note?
> If there is no response from Elecraft, what have other ops done--short of moving the PS into an adjoining room--to mitigate the scream?
> Thanks,
> 73 Eric WD6DBM
>
> Sent from Yahoo Mail on Android
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--
Scott K9MA

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