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KPA500 question about cooling

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Bill Clarke

KPA500 question about cooling

Is it necessary that the top of the amp be unblocked? I was thinking of
the KAT500 being placed on top of the amp. Perhaps the other way around
would be better? Any side clearances required?

I am designing a new radio desk that will house my K3, P3, and yet to be
purchased amp and tuner.

Thanks, Bill W2BLC
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mcduffie

Re: KPA500 question about cooling

On Sun, 26 May 2013 16:40:48 -0400, Bill wrote:

> Is it necessary that the top of the amp be unblocked? I was thinking of
> the KAT500 being placed on top of the amp. Perhaps the other way around
> would be better? Any side clearances required?

You'll find out when you build the KPA that the top needs to be kept clear. Air
intake is at the top, and exhaust at the rear. It moves a lot of air when the
fan hits high gear :) Others have put the tuner under the amp. It also helps
to hold the tuner down when you hit a button. I'm more than likely going to do
the same thing when I get mine.

Gary
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K9QJS

Re: KPA500 question about cooling

In reply to this post by Bill Clarke

BIll,

The KAT500 Elecraft page shows a photo from Visalia with the KAT500 placed on top of the amp.

http://www.elecraft.com/KAT500/kat500.html

I'm planning on stacking one on top of the other, myself, when I add them both to my shack.

73,
Hoop
K9QJS

On May 26, 2013, at 1:40 PM, Bill <[hidden email]> wrote:

Is it necessary that the top of the amp be unblocked? I was thinking of the KAT500 being placed on top of the amp. Perhaps the other way around would be better? Any side clearances required?

I am designing a new radio desk that will house my K3, P3, and yet to be purchased amp and tuner.

Thanks, Bill W2BLC
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mcduffie

Re: KPA500 question about cooling

In reply to this post by Bill Clarke

On Sun, 26 May 2013 15:06:25 -0700, Ron D'Eau Claire wrote:

> The KAT500 may be placed on TOP or under the KPA500.

I wouldn't put it on top. I can hear fan and air changes if I get within a half
inch of the intake slots with my hand at higher speeds. You can feel the air
flow considerably at high speed with your hand an inch over the opening. That
means it does affect the airflow to put something that close. I don't care if
the factory or a manual says you can do it. I sure wouldn't run mine that way.

Gary
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Dick Dievendorff

Re: KPA500 question about cooling

In reply to this post by Bill Clarke

> If you put the KAT500 above the amp the fans run more often, but are able to keep the amp cool enough for most normal uses. K6XX did test this early on with thermometers. It comes up to fan temp more quickly, but settles at the same temp. I have mine above the amp, but the amp can also be above the ATU, which is what I might do except that the cover of my ATU is off most of the time for a firmware debug cable.

Putting the amp over the ATU helps keep the ATU in place if you are troubled by cables tending to move the ATU.

I like the look of K3, P3, and KAT500 lined up. I don't need to operate controls on either the amp or ATU often enough to make it a significant ergonomic issue. I do care about the height of the K3 above the desk tho.

If I were a RTTY contester in the tropics, I would allow more than minimum clear air space around the rig and amp.

It's a personal choice issue.

73 de Dick, K6KR

On May 26, 2013, at 1:40 PM, Bill <[hidden email]> wrote:

> Is it necessary that the top of the amp be unblocked? I was thinking of the KAT500 being placed on top of the amp. Perhaps the other way around would be better? Any side clearances required?
>
> I am designing a new radio desk that will house my K3, P3, and yet to be purchased amp and tuner.
>
> Thanks, Bill W2BLC
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
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>
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John Bastin

Re: KPA500 question about cooling

In reply to this post by mcduffie

On 26 May 2013, at 4:47 PM, [hidden email] wrote:

> On Sun, 26 May 2013 16:40:48 -0400, Bill wrote:
>
>> Is it necessary that the top of the amp be unblocked? I was thinking of
>> the KAT500 being placed on top of the amp. Perhaps the other way around
>> would be better? Any side clearances required?
>
> You'll find out when you build the KPA that the top needs to be kept clear. Air
> intake is at the top, and exhaust at the rear. It moves a lot of air when the
> fan hits high gear :) Others have put the tuner under the amp. It also helps
> to hold the tuner down when you hit a button. I'm more than likely going to do
> the same thing when I get mine.

I thought that, too, so when I set up my K-Line I put the KAT500 under the KPA500 on the desk. Then I saw the setup at Dayton, where they had the KPA500 with the KAT500 on top.

I asked the person at the booth and he told me that there is no problem running the amp with the tuner on top, that they are designed to have adequate cooling when installed in that position.

Hope this helps.

John K8AJS
[hidden email]

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Sebastian, W4AS

Re: KPA500 question about cooling

In reply to this post by mcduffie

I do a lot of meteor scatter on 6 meters, and I've tried the tuner both above and below the amp.

I've found the KPA500 runs cooler with the KAT500 tuner below the amp.

73 de Sebastian, W4AS

On May 26, 2013, at 6:23 PM, [hidden email] wrote:

> On Sun, 26 May 2013 15:06:25 -0700, Ron D'Eau Claire wrote:
>
>> The KAT500 may be placed on TOP or under the KPA500.
>
> I wouldn't put it on top. I can hear fan and air changes if I get within a half
> inch of the intake slots with my hand at higher speeds. You can feel the air
> flow considerably at high speed with your hand an inch over the opening. That
> means it does affect the airflow to put something that close. I don't care if
> the factory or a manual says you can do it. I sure wouldn't run mine that way.
>
> Gary

Richard Gillingham

Re: KPA500 question about cooling

Yes.
The very first statement under Installation in the KPA500 owner's manual is the following:

"IMPORTANT: Provide at least 2 inches (5 cm) clearance behind the fan and above the amplifier for proper air flow."

Nuf said.

73,
Gil, W1RG

> From: [hidden email]
> Date: Sun, 26 May 2013 23:39:00 -0400
> To: [hidden email]
> Subject: Re: [Elecraft] KPA500 question about cooling
>
> I do a lot of meteor scatter on 6 meters, and I've tried the tuner both above and below the amp.
>
> I've found the KPA500 runs cooler with the KAT500 tuner below the amp.
>
> 73 de Sebastian, W4AS
>
>
>
> On May 26, 2013, at 6:23 PM, [hidden email] wrote:
>
> > On Sun, 26 May 2013 15:06:25 -0700, Ron D'Eau Claire wrote:
> >
> >> The KAT500 may be placed on TOP or under the KPA500.
> >
> > I wouldn't put it on top. I can hear fan and air changes if I get within a half
> > inch of the intake slots with my hand at higher speeds. You can feel the air
> > flow considerably at high speed with your hand an inch over the opening. That
> > means it does affect the airflow to put something that close. I don't care if
> > the factory or a manual says you can do it. I sure wouldn't run mine that way.
> >
> > Gary
>
> ______________________________________________________________
> Elecraft mailing list
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N0AZZ

Re: KPA500 question about cooling

I guess it boils down to whatever trips your trigger and the people who
designed it said to put it on top if you wanted, no problems.

73,
Fred/N0AZZ
K3 Ser #'s 6730/5299--KX3 # 2573--K2/100--KAT100
P3/SVGA--KPA500--KAT500--W2

-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of Richard Gillingham
Sent: Monday, May 27, 2013 8:31 AM
To: [hidden email]
Subject: Re: [Elecraft] KPA500 question about cooling

Yes.
The very first statement under Installation in the KPA500 owner's manual is
the following:

"IMPORTANT: Provide at least 2 inches (5 cm) clearance behind the fan and
above the amplifier for proper air flow."

Nuf said.

73,
Gil, W1RG

> From: [hidden email]
> Date: Sun, 26 May 2013 23:39:00 -0400
> To: [hidden email]
> Subject: Re: [Elecraft] KPA500 question about cooling
>
> I do a lot of meteor scatter on 6 meters, and I've tried the tuner both
above and below the amp.

>
> I've found the KPA500 runs cooler with the KAT500 tuner below the amp.
>
> 73 de Sebastian, W4AS
>
>
>
> On May 26, 2013, at 6:23 PM, [hidden email] wrote:
>
> > On Sun, 26 May 2013 15:06:25 -0700, Ron D'Eau Claire wrote:
> >
> >> The KAT500 may be placed on TOP or under the KPA500.
> >
> > I wouldn't put it on top. I can hear fan and air changes if I get

within a half
> > inch of the intake slots with my hand at higher speeds. You can feel
the air
> > flow considerably at high speed with your hand an inch over the opening.
That
> > means it does affect the airflow to put something that close. I don't
care if
> > the factory or a manual says you can do it. I sure wouldn't run mine
that way.

> >
> > Gary
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
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>
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> Please help support this email list: http://www.qsl.net/donate.html

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alsopb

Re: KPA500 question about cooling

Keep in mind the fan may come on more and end up at higher speeds more
ofter if you put the KAT500 on top. That is not to say it will
overheat. Fan noise for some is a KPA500 issue.

73 de Brian/K3KO

On 5/27/2013 13:39, Fred Smith wrote:

> I guess it boils down to whatever trips your trigger and the people who
> designed it said to put it on top if you wanted, no problems.
>
>
> 73,
> Fred/N0AZZ
> K3 Ser #'s 6730/5299--KX3 # 2573--K2/100--KAT100
> P3/SVGA--KPA500--KAT500--W2
>
>
>
> -----Original Message-----
> From: [hidden email]
> [mailto:[hidden email]] On Behalf Of Richard Gillingham
> Sent: Monday, May 27, 2013 8:31 AM
> To: [hidden email]
> Subject: Re: [Elecraft] KPA500 question about cooling
>
> Yes.
> The very first statement under Installation in the KPA500 owner's manual is
> the following:
>
> "IMPORTANT: Provide at least 2 inches (5 cm) clearance behind the fan and
> above the amplifier for proper air flow."
>
> Nuf said.
>
> 73,
> Gil, W1RG
>
>
>> From: [hidden email]
>> Date: Sun, 26 May 2013 23:39:00 -0400
>> To: [hidden email]
>> Subject: Re: [Elecraft] KPA500 question about cooling
>>
>> I do a lot of meteor scatter on 6 meters, and I've tried the tuner both
> above and below the amp.
>>
>> I've found the KPA500 runs cooler with the KAT500 tuner below the amp.
>>
>> 73 de Sebastian, W4AS
>>
>>
>>
>> On May 26, 2013, at 6:23 PM, [hidden email] wrote:
>>
>>> On Sun, 26 May 2013 15:06:25 -0700, Ron D'Eau Claire wrote:
>>>
>>>> The KAT500 may be placed on TOP or under the KPA500.
>>>
>>> I wouldn't put it on top. I can hear fan and air changes if I get
> within a half
>>> inch of the intake slots with my hand at higher speeds. You can feel
> the air
>>> flow considerably at high speed with your hand an inch over the opening.
> That
>>> means it does affect the airflow to put something that close. I don't
> care if
>>> the factory or a manual says you can do it. I sure wouldn't run mine
> that way.
>>>
>>> Gary
>>
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:[hidden email]
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
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>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 2013.0.2904 / Virus Database: 3184/6360 - Release Date: 05/26/13
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 2013.0.2904 / Virus Database: 3184/6360 - Release Date: 05/26/13
>
> ______________________________________________________________
> Elecraft mailing list
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>
>
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> Checked by AVG - www.avg.com
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>
>

-----
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Checked by AVG - www.avg.com
Version: 2012.0.2242 / Virus Database: 3184/5861 - Release Date: 05/27/13

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mcduffie

Re: KPA500 question about cooling

In reply to this post by Bill Clarke

On Mon, 27 May 2013 09:31:23 -0400, Richard Gillingham wrote:

> "IMPORTANT: Provide at least 2 inches (5 cm) clearance behind the
> fan and above the amplifier for proper air flow."
>
> Nuf said.

Roger that! And yes, the fan makes PLENTY of noise when it kicks up to
high speed. It isn't enough that my cardioid mic picks it up, but it
blows the curtain about 2 feet behind it. :o)

Gary
--
http://ag0n.net
3055: http://ag0n.net/irlp/3055
NodeOp Help Page: http://ag0n.net/irlp
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Richard Gillingham

Re: KPA500 question about cooling

In reply to this post by Richard Gillingham

Very well.
Generally I do try to "Do as the manufacturer says." Especially with expensive stuff still under warranty..
Fortunately I built my own shelving for the shack and I've got room for the KAT500 just above the amp. All's well.

Thanks for the heads up on the overly protective caution in the manual. Maybe we'll see a change soon.

73
Gil, W1RG

> From: [hidden email]
> To: [hidden email]; [hidden email]
> Subject: RE: [Elecraft] KPA500 question about cooling
> Date: Mon, 27 May 2013 08:03:34 -0700
>
> Aha. You caught something that needs fixing Gil. I'm not an Elecraft
> employee but do write some of their manuals. The 2" spec goes way back
> before the KAT500 was released. When the KAT500 came along, the engineers
> insisted the smaller spacing on top afforded by the KAT500 feet was adequate
> clearance.
>
> 73 Ron AC7AC
>
> -----Original Message-----
> From: [hidden email]
> [mailto:[hidden email]] On Behalf Of Richard Gillingham
> Sent: Monday, May 27, 2013 6:31 AM
> To: [hidden email]
> Subject: Re: [Elecraft] KPA500 question about cooling
>
> Yes.
> The very first statement under Installation in the KPA500 owner's manual is
> the following:
>
> "IMPORTANT: Provide at least 2 inches (5 cm) clearance behind the fan and
> above the amplifier for proper air flow."
>
> Nuf said.
>
> 73,
> Gil, W1RG
>

Don Wilhelm-4

Re: KPA500 question about cooling

In reply to this post by alsopb

Those who know something about fluid dynamics can also tell you that if
the air flow is restricted, the fan speed will be a bit higher (for any
given KPA500 selected fan speed) - it is because the fan is not doing as
much work to move air.
Try an experiment with any fan - partially block the air flow and
observe that the fan speed increases.
That is more noticeable if the outlet side is blocked - so do maintain
the proper clearance at the back of the KPA500.

73,
Don W3FPR

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