KPA-500 fan noise

[James Rogers]

     I have been running some RTTY on 17M and FSK-441 on 6M meteor
scatter, both of which have full period signals for 30 seconds or so.  I
have reduced power to 250W, but by the end of a transmissions the fan
has gone to 747 short field take off mode at about 71C.  Am I missing
something here or is this normal?

JIm, W4ATK
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[mcduffie]

> Am I missing
> something here or is this normal?

Sounds normal for mine.  I've recently had mine on 52.525 in an FM QSO.  I ended
up at about 250W with short transmissions.  That didn't surprise me much at all,
because my KPA seems to produce quite a bit of heat on six meters anyway.  Hit
the dummy load and do some continuous carrier testing and see how long it takes
to hit high speed.  It won't take long.  That's one screaming fan.

By the way, you can sample those speeds just by going to the menu and changing
the fan control setting.  That menu item sets the minimum speed the fan will run
(auto = off when below threshold).  One thing you might try is to set the fan to
the first or second speed (not auto) when you're operating those modes.  That
let's the fan run all the time at the speed you set, which allows it to cool in
receive mode when it might normally kick down to the off mode until you key the
next time.  Don't miss understand, the fan control menu sets the MINIMUM speed
the fan runs.  It still kicks up faster for warmer operation.

Gary
--
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[Jim Brown-10]

On 6/1/2014 5:59 PM, AG0N-3055 wrote:
> Sounds normal for mine.

Yes, quite normal. The KPA500 is very well protected, while still
allowing as much power output as possible. I do lots of RTTY contesting
on HF, and JT65 on several bands, including 6M. Depending on the ambient
temperature in the shack, the fan kicks into high gear after about 40
seconds, but the power remains at maximum.

I ran a beta KPA500 for a RTTY contest weekend, with instructions to run
it "with all the lights lit." I did, with no issues, and that's how I've
always run it.

BTW -- with many classes of power amps, greatest dissipation is not at
full power, but at some lower power level, and it is my understanding
this is true with the KPA500. So backing off TX power probably isn't
necessary, and if it is, the KPA500 will do it on its own.

73, Jim K9YC


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[James Rogers]

Thanks to all who replied.  If I did not have to cut a hole in the sheet
rock, I would install a dryer vent!! I think I will try setting the fan
to a minimum speed as suggested and see how that works out keeping the
air moving all the time.

73s Jim, W4ATK
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[Elecraft mailing list]

You could always try replacing the fan with a quieter fan.
I do not have the KPA500 (Yet) but I did replace both the Fans on The K3 with Fans from Noctua.
They are a lot quieter, The only downside is the color of the Fans, but not a big deal since they are in the back




________________________________
 From: Jim Rogers <[hidden email]>
To: [hidden email]
Sent: Monday, June 2, 2014 7:26 AM
Subject: Re: [Elecraft] KPA-500 fan noise
 

Thanks to all who replied.  If I did not have to cut a hole in the sheet
rock, I would install a dryer vent!! I think I will try setting the fan
to a minimum speed as suggested and see how that works out keeping the
air moving all the time.

73s Jim, W4ATK
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[mcduffie]

On Mon, 2 Jun 2014 06:05:22 -0700 (PDT), Harry Yingst via Elecraft
wrote:

> You could always try replacing the fan with a quieter fan.

I would consider that myself, but only with one recommended by the good
people at Elecraft.  The fan in the KPA is VERY loud when it hits the
last two speeds.  Warp and Turbo Warp would wake my wife in the next
room if she was a light sleeper, although I virtually never get it up
that warm.  It was just my short excursion on 6M FM that really got it
up there fast.  My issue isn't with the fan operation, although I wish
it would come on just a bit earlier than it does.  My issue is with the
sound level out of this particular fan.  It's a screaming banshee when
it gets up there at speed.  It's a very "raw" sound, not the sound of
air moving, but of a high speed motor.

My only hesitation with putting a different fan in it would be
compatibility with the speed control circuitry.  I just won't do it,
especially under warranty, without Elecraft's recommendation and
blessing.  They've got a good product and I want to keep it that way.

Typing this up raised my curiosity and I went to the shack and ran a
control test into my Bird load.  I set my rig at 10W on 52.525 FM, which
gives me 200W output.  With manual fan control, I made sure the amp was
cooled to 33C as a starting point, and then set the fan back to NORmal
setting.  I keyed the rig on FM at the (unmeasured) 10W setting, and sat
back to see what it did.  It took 75 seconds to reach 70C.  At which
point, the fan is at 5, a rather noisy speed.  It seemed to level out at
77-78C for a bit and then went to 80C at 4:50 minutes.  I ended the test
at that point.  At 80, the fan went to 6, the highest speed, screaming
away.  With this test, I'm confident that it would probably handle
anything I would ever do to it in normal operation, especially given the
fact that I'm not dumb enough to do that test at 500W output.  :o)  I
think the fan does a pretty good job, but do wish it was quieter.  I
never hit those higher speeds, except in test conditions like this.  My
normal use has it hitting 70C only on the rarest of occasions.

Gary
--
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3055: http://ag0n.net/irlp/3055
NodeOp Help Page: http://ag0n.net/irlp
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[Jim Brown-10]

On 6/2/2014 7:56 AM, AG0N-3055 wrote:
>> You could always try replacing the fan with a quieter fan.
> I would consider that myself, but only with one recommended by the good people at Elecraft.

It is generally a bad idea to try to re-engineer a product, especially
one that is well designed. In this case, I would consider it a really
bad idea.

73, Jim K9YC
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[k6dgw]

Our "Beverage Central" is located in my shack.  I was contemplating
putting a heat exchanger on the KAP500 PA's and routing cold water from
the drink fridge through it.  I guess that would class as
"re-engineering?"  Haven't figured out how to get the plumbing out of
the fridge, however.

73,

Fred K6DGW
- Northern California Contest Club
- CU in the 2014 Cal QSO Party 4-5 Oct 2014
- www.cqp.org

On 6/2/2014 8:16 AM, Jim Brown wrote:
> On 6/2/2014 7:56 AM, AG0N-3055 wrote:
>>> You could always try replacing the fan with a quieter fan.
>> I would consider that myself, but only with one recommended by the
>> good people at Elecraft.
>
> It is generally a bad idea to try to re-engineer a product, especially
> one that is well designed. In this case, I would consider it a really
> bad idea.


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[Fred Townsend-2]

I would hate to think what would happen if a water line breaks. Why not duct the air from a portable AC unit to the KPA-500. Then when the ducting breaks you won't have water all over the place... just cool air.
Seriously folks, any chance the exhaust air from the KPA is being fed back into the air intake for the KPA? That will heat things up in a hurry. Maybe outside air (depending where you live) ducted to the KPA would keep things cooler. Failing that just empty the contents of the beverage cooler into your stomach and after a while the whole room will be spinning. The fans will be still running but you won't notice.
73
Fred, AE6QL

-----Original Message-----

>From: Fred Jensen <[hidden email]>
>Sent: Jun 2, 2014 8:28 AM
>To: [hidden email]
>Subject: Re: [Elecraft] KPA-500 fan noise
>
>Our "Beverage Central" is located in my shack.  I was contemplating
>putting a heat exchanger on the KAP500 PA's and routing cold water from
>the drink fridge through it.  I guess that would class as
>"re-engineering?"  Haven't figured out how to get the plumbing out of
>the fridge, however.
>
>73,
>
>Fred K6DGW
>- Northern California Contest Club
>- CU in the 2014 Cal QSO Party 4-5 Oct 2014
>- www.cqp.org
>
>On 6/2/2014 8:16 AM, Jim Brown wrote:
>> On 6/2/2014 7:56 AM, AG0N-3055 wrote:
>>>> You could always try replacing the fan with a quieter fan.
>>> I would consider that myself, but only with one recommended by the
>>> good people at Elecraft.
>>
>> It is generally a bad idea to try to re-engineer a product, especially
>> one that is well designed. In this case, I would consider it a really
>> bad idea.
>
>
>______________________________________________________________
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[riese-k3djc]

you guys

add one of these less strain on the fan and ur ears

Bob K3DJC

http://en.wikipedia.org/wiki/Thermoelectric_cooling



n Mon, 2 Jun 2014 08:46:45 -0700 (GMT-07:00) Fred Townsend
<[hidden email]> writes:

> I would hate to think what would happen if a water line breaks. Why
> not duct the air from a portable AC unit to the KPA-500. Then when
> the ducting breaks you won't have water all over the place... just
> cool air.
> Seriously folks, any chance the exhaust air from the KPA is being
> fed back into the air intake for the KPA? That will heat things up
> in a hurry. Maybe outside air (depending where you live) ducted to
> the KPA would keep things cooler. Failing that just empty the
> contents of the beverage cooler into your stomach and after a while
> the whole room will be spinning. The fans will be still running but
> you won't notice.
> 73
> Fred, AE6QL
>
> -----Original Message-----
> >From: Fred Jensen <[hidden email]>
> >Sent: Jun 2, 2014 8:28 AM
> >To: [hidden email]
> >Subject: Re: [Elecraft] KPA-500 fan noise
> >
> >Our "Beverage Central" is located in my shack.  I was contemplating
>
> >putting a heat exchanger on the KAP500 PA's and routing cold water
> from
> >the drink fridge through it.  I guess that would class as
> >"re-engineering?"  Haven't figured out how to get the plumbing out
> of
> >the fridge, however.
> >
> >73,
> >
> >Fred K6DGW
> >- Northern California Contest Club
> >- CU in the 2014 Cal QSO Party 4-5 Oct 2014
> >- www.cqp.org
> >
> >On 6/2/2014 8:16 AM, Jim Brown wrote:
> >> On 6/2/2014 7:56 AM, AG0N-3055 wrote:
> >>>> You could always try replacing the fan with a quieter fan.
> >>> I would consider that myself, but only with one recommended by
> the
> >>> good people at Elecraft.
> >>
> >> It is generally a bad idea to try to re-engineer a product,
> especially
> >> one that is well designed. In this case, I would consider it a
> really
> >> bad idea.
> >
> >
> >______________________________________________________________
> >Elecraft mailing list
> >Home: http://mailman.qth.net/mailman/listinfo/elecraft
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>
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>

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[Richard Squire - HB9ANM]

If you set fan speed to Level 1 in the first place, it will run
continuously and avoid wide temperature variations.
I can work pileups in RTTY at 500W and the fan goes into Level 2 on rare
occasions and for a short time only.
IMHO, the NORmal setting is not the best one. Level 1 (constant) is very
quiet and a better choice to protect the Mosfets.

73
Richard - HB9ANM

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[Fred Townsend-2]

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[Fred Townsend-2]

How would that work Bob? Actually Peltier junctions do not create cold. They move heat and then the distance the heat is moved is less than a quarter inch and you end up with more heat than you started with. BTW you need a heat sink for the back side of the Peltier. Back to square one. You can get more cooling from an ice cube.
73
Fred, AE6QL



-----Original Message-----

>From: [hidden email]
>Sent: Jun 2, 2014 9:29 AM
>To: [hidden email]
>Cc: [hidden email], [hidden email]
>Subject: Re: [Elecraft] KPA-500 fan noise
>
>you guys
>
>add one of these less strain on the fan and ur ears
>
>Bob K3DJC
>
>http://en.wikipedia.org/wiki/Thermoelectric_cooling
>
>
>
>n Mon, 2 Jun 2014 08:46:45 -0700 (GMT-07:00) Fred Townsend
><[hidden email]> writes:
>> I would hate to think what would happen if a water line breaks. Why
>> not duct the air from a portable AC unit to the KPA-500. Then when
>> the ducting breaks you won't have water all over the place... just
>> cool air.
>> Seriously folks, any chance the exhaust air from the KPA is being
>> fed back into the air intake for the KPA? That will heat things up
>> in a hurry. Maybe outside air (depending where you live) ducted to
>> the KPA would keep things cooler. Failing that just empty the
>> contents of the beverage cooler into your stomach and after a while
>> the whole room will be spinning. The fans will be still running but
>> you won't notice.
>> 73
>> Fred, AE6QL
>>
>> -----Original Message-----
>> >From: Fred Jensen <[hidden email]>
>> >Sent: Jun 2, 2014 8:28 AM
>> >To: [hidden email]
>> >Subject: Re: [Elecraft] KPA-500 fan noise
>> >
>> >Our "Beverage Central" is located in my shack.  I was contemplating
>>
>> >putting a heat exchanger on the KAP500 PA's and routing cold water
>> from
>> >the drink fridge through it.  I guess that would class as
>> >"re-engineering?"  Haven't figured out how to get the plumbing out
>> of
>> >the fridge, however.
>> >
>> >73,
>> >
>> >Fred K6DGW
>> >- Northern California Contest Club
>> >- CU in the 2014 Cal QSO Party 4-5 Oct 2014
>> >- www.cqp.org
>> >
>> >On 6/2/2014 8:16 AM, Jim Brown wrote:
>> >> On 6/2/2014 7:56 AM, AG0N-3055 wrote:
>> >>>> You could always try replacing the fan with a quieter fan.
>> >>> I would consider that myself, but only with one recommended by
>> the
>> >>> good people at Elecraft.
>> >>
>> >> It is generally a bad idea to try to re-engineer a product,
>> especially
>> >> one that is well designed. In this case, I would consider it a
>> really
>> >> bad idea.
>> >
>> >
>> >______________________________________________________________
>> >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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>>
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>>
>

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[Eric Swartz - WA6HHQ]

Let's end this thread for now, since the original poster has had his query
answered. (And in the interest of keeping list volume under control.)

73,
Eric
List moderator
elecraft.com

On 6/2/2014 10:21 AM, Fred Townsend wrote:
> How would that work Bob? Actually Peltier junctions do not create cold. They move heat and then the distance the heat is moved is less than a quarter inch and you end up with more heat than you started with. BTW you need a heat sink for the back side of the Peltier. Back to square one. You can get more cooling from an ice cube.
> 73
> Fred, AE6QL
>
>

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[KB9WMJ]

Has anyone else encountered this?

My AVG virus S/W is saying that my K3 MARS mod (which I have not used yet)
contains the Win32/DH virus.

I e-mailed Elecraft a week ago, but got no response.


Keith
KB9WMJ

 

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[Dick Diddams]

My comment is not to K6GPW, but to the continuously number of postings
regarding Fan Noise.

1) Would someone measure (quantify) the "objectionable" noise (using a sound
meter) and report their dB findings.  

2) Determine a sound level (measurement) that is acceptable (based upon
normal ears).  

3) Describe how / where the amplifier is located; possibly the amplifier is
in a position where sound is reverberating off a wall, metal file cabinet,
wooden or plastic shelf, (possibly the amplifier enclosure itself), etc..  

4) What is the noise specification of the fan in the amplifier provided by
the manufacturer - is it being exceeded.

5) How loud is "too loud" - my ears or your ears?  

6) Is there an industry standard for reference in measuring the KPA500
"noise"?

 

Someone who is/are audio experts can provide a methodology on how to
properly measure (fan) noise.  Baseline fan noise must be measured in an
environment where other artifacts are not influencing (amplifying) the
"real" sound level and away from the operating station to obtain a true
level of the fan noise. The measurement methodology must be capable of being
duplicated by others with results within instrument accuracies.  Next repeat
measurements with the amplifier in the operating position.  At least, at
this time, one would know if there is an increase in "fan" noise level, if
the noise increases, it probably isn't the fan.

 

Possibly a simple solution to those with sensitive ears is placing sound
absorbing material between the wall and amplifier, or a baffle above the
amplifier slanting towards sound absorbing material.  Or lastly, just suck
it up and live with the "noise".

 

It very well could be, the artifact of undesirable fan noise can, only be
resolved by usage of headphones or sell your amplifier - if the price is
right, I'll buy yours!  "hi"

 

BTW, my KPA500 does not have an objectionable fan noise.  I didn't use the
word "loud" or "soft: because I do not know what the definition of "loud" or
"soft" may be!  If I could borrow a noise meter, I'd measure my amplifier
and let everyone what a "desirable" noise level should be!  "hi"

 

Owner of K1, K2, K3, KPA500, KAT500 and several other pieces of Elecraft
products.

 

73, Dick - W7QHE/4

 

=======================

 

Message: 9

Date: Mon, 02 Jun 2014 08:28:28 -0700

From: Fred Jensen <[hidden email] <mailto:[hidden email]> >

To: [hidden email] <mailto:[hidden email]>

Subject: Re: [Elecraft] KPA-500 fan noise

 

Our "Beverage Central" is located in my shack.  I was contemplating putting
a heat exchanger on the KAP500 PA's and routing cold water from the drink
fridge through it.  I guess that would class as

"re-engineering?"  Haven't figured out how to get the plumbing out of the
fridge, however.

 

73,

 

Fred K6DGW

- Northern California Contest Club

- CU in the 2014 Cal QSO Party 4-5 Oct 2014

- www.cqp.org <http://www.cqp.org/>

 

On 6/2/2014 8:16 AM, Jim Brown wrote:

> On 6/2/2014 7:56 AM, AG0N-3055 wrote:

>>> You could always try replacing the fan with a quieter fan.  I would
consider that myself, but only with >>> one recommended by the good people
at Elecraft.

>

> It is generally a bad idea to try to re-engineer a product, especially one
that is well designed. In this > > > case, I would consider it a really bad
idea.

 

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[Jim Brown-10]

On 6/2/2014 7:55 PM, Richard L Diddams, Sr. wrote:
> My comment is not to K6GPW, but to the continuously number of postings regarding Fan Noise.

Far more than necessary, IMO.  Dick, the fan speed is adjusted by the
control system based on temperature of the output devices, which you can
monitor from the front panel. The fan speed gradually increases as the
temperature passes lower temperature thresholds, but it really kicks
into high gear at about 71 degrees C.

If you want to hear what this sounds like, put a brick on the key and
crank the amp to rated power for a minute or so. Depending on ambient
and air flow in your shack, you'll hear it kick in, and if you have the
instrumentation to do so, can measure it yourself.

My fan kicks in roughly 40-45 seconds into a keydown transmission on 6M,
and very occasionally, briefly, when I'm RTTY contesting, calling CQ
near the end of the contest with few responses. In normal contesting,
where you're sitting on a frequency and running stations at several a
minute, the duty cycle is low enough that the high fan speed rarely
kicks in.

Could the noise level be reduced by some design advice from a good
acoustic consultant? Sure. I can recommend several who work on making
HVAC systems in theaters and concert halls dead quiet. How much cost
would you like to add to your KPA500?

The sound pressure level at that high is nothing more than annoying,
certainly nothing to be alarmed about from a hearing damage point of
view, and it's a lot less annoying if you're wearing cans. And for
keydown modes like AM, FM, PSK, and RTTY, there's even a side benefit --
when the fan speeds up, you've probably been going on too long about
nothing, so it works to prevent you from boring the other member(s) of
the QSO.

73, Jim K9YC


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[Mike Reublin]

Most likely a false positive. Do you know which of the Elecraft guys wrote it? Did they email it to you or did you download it?

Contact Elecraft again. It's not like them to be non responsive. Then notify AVG so they can correct their software.

73, Mike NF4L

On Jun 2, 2014, at 5:21 PM, <[hidden email]> <[hidden email]> wrote:

> Has anyone else encountered this?
>
> My AVG virus S/W is saying that my K3 MARS mod (which I have not used yet)
> contains the Win32/DH virus.
>
> I e-mailed Elecraft a week ago, but got no response.
>
>
> Keith
> KB9WMJ
>
>
>
> ______________________________________________________________
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[Elecraft mailing list]

I would tend to believe that replacing the cheap fans with
higher quality fans would be a improvement in design. 

If the K3 cannot handle what little extra current draw the fans have 
then I would certainly question the well engineered aspect of it.

As in any product cost is a factor and I'm sure Elecraft
has to weigh the cost associated with various parts.

For many the noise will not bother them for others it will so for the ones
who  do find the additional noise bothersome they can simply swap out
the fans for a higher quality fan and enjoy the reduction in fan noise.

To my ears (and I'm partially deaf from when I was in the Navy) the stock
fans in the K3 had a grating sound that added to the background noise.
Replacing the fans was a worthwhile improvement and made copy easier.

I'm not afraid of improving a design where there is room for improvement.








________________________________
 From: Jim Brown <[hidden email]>
To: [hidden email]
Sent: Monday, June 2, 2014 11:16 AM
Subject: Re: [Elecraft] KPA-500 fan noise
 

On 6/2/2014 7:56 AM, AG0N-3055 wrote:
>> You could always try replacing the fan with a quieter fan.
> I would consider that myself, but only with one recommended by the good people at Elecraft.

It is generally a bad idea to try to re-engineer a product, especially
one that is well designed. In this case, I would consider it a really
bad idea.

73, Jim K9YC
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[Phil Wheeler-2]

I've never heard any of the fans (K3 or KPA500)
except when I shut down the KPA500 for a  short
time.  So I need no "criteria" :-)

73, Phil W7OX

On 6/2/14, 7:55 PM, Richard L Diddams, Sr. wrote:

> My comment is not to K6GPW, but to the continuously number of postings
> regarding Fan Noise.
>
> 1) Would someone measure (quantify) the "objectionable" noise (using a sound
> meter) and report their dB findings.
>
> 2) Determine a sound level (measurement) that is acceptable (based upon
> normal ears).
>
> 3) Describe how / where the amplifier is located; possibly the amplifier is
> in a position where sound is reverberating off a wall, metal file cabinet,
> wooden or plastic shelf, (possibly the amplifier enclosure itself), etc..
>
> 4) What is the noise specification of the fan in the amplifier provided by
> the manufacturer - is it being exceeded.
>
> 5) How loud is "too loud" - my ears or your ears?
>
> 6) Is there an industry standard for reference in measuring the KPA500
> "noise"?
>
>  
>
> Someone who is/are audio experts can provide a methodology on how to
> properly measure (fan) noise.  Baseline fan noise must be measured in an
> environment where other artifacts are not influencing (amplifying) the
> "real" sound level and away from the operating station to obtain a true
> level of the fan noise. The measurement methodology must be capable of being
> duplicated by others with results within instrument accuracies.  Next repeat
> measurements with the amplifier in the operating position.  At least, at
> this time, one would know if there is an increase in "fan" noise level, if
> the noise increases, it probably isn't the fan.
>
>  
>
> Possibly a simple solution to those with sensitive ears is placing sound
> absorbing material between the wall and amplifier, or a baffle above the
> amplifier slanting towards sound absorbing material.  Or lastly, just suck
> it up and live with the "noise".
>
>  
>
> It very well could be, the artifact of undesirable fan noise can, only be
> resolved by usage of headphones or sell your amplifier - if the price is
> right, I'll buy yours!  "hi"
>
>  
>
> BTW, my KPA500 does not have an objectionable fan noise.  I didn't use the
> word "loud" or "soft: because I do not know what the definition of "loud" or
> "soft" may be!  If I could borrow a noise meter, I'd measure my amplifier
> and let everyone what a "desirable" noise level should be!  "hi"
>
>  
>
> Owner of K1, K2, K3, KPA500, KAT500 and several other pieces of Elecraft
> products.
>
>  
>
> 73, Dick - W7QHE/4
>
>  
>
> =======================
>
>  
>
> Message: 9
>
> Date: Mon, 02 Jun 2014 08:28:28 -0700
>
> From: Fred Jensen <[hidden email] <mailto:[hidden email]> >
>
> To: [hidden email] <mailto:[hidden email]>
>
> Subject: Re: [Elecraft] KPA-500 fan noise
>
>  
>
> Our "Beverage Central" is located in my shack.  I was contemplating putting
> a heat exchanger on the KAP500 PA's and routing cold water from the drink
> fridge through it.  I guess that would class as
>
> "re-engineering?"  Haven't figured out how to get the plumbing out of the
> fridge, however.
>
>  
>
> 73,
>
>  
>
> Fred K6DGW
>
> - Northern California Contest Club
>
> - CU in the 2014 Cal QSO Party 4-5 Oct 2014
>
> - www.cqp.org <http://www.cqp.org/>
>
>  
>
> On 6/2/2014 8:16 AM, Jim Brown wrote:
>
>> On 6/2/2014 7:56 AM, AG0N-3055 wrote:
>>>> You could always try replacing the fan with a quieter fan.  I would
> consider that myself, but only with >>> one recommended by the good people
> at Elecraft.
>
>> It is generally a bad idea to try to re-engineer a product, especially one
> that is well designed. In this > > > case, I would consider it a really bad
> idea.

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