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Re: [Amps] Arctic Silver

from [Roger (K8RI)] [Permanent Link][Original]
To: amps@contesting.com
Subject: Re: [Amps] Arctic Silver
From: "Roger (K8RI)" <k8ri@rogerhalstead.com>
Date: Thu, 12 Dec 2013 02:26:20 -0500
List-post: <amps@contesting.com">mailto:amps@contesting.com> 
On 12/12/2013 12:12 AM, David Lisney wrote:

Hi,
I have used Arctic Silver in the normal computer CPU application (a twin cpu computer 
with homebrew watercoolers etc) it did produce a lower thermal resistance junction than 
the conventional white heatsink compound. Lapping the mating surfaces was also helpful, I 
did this with progressively finer "wet and dry" emery paper on a sheet of glass.
I have used Arctic Silver since in RF applications but can't remember in what!
It is now my "preferred" heatsink conpound, these posts have reminded me to buy 
more.
Arctic Silver is one of the best heatsink compounds. Use as little as possible and still get full coverage. It may take a few tries to get the amount right. When redoing, clean the old off with denatured alcohol on a cotton ball. After it has been in place for a few thermal cycles, it can become quite solid. For those not familiar, you start with enough on a spot in the center of the area to be covered and then spread it using a small circular motion. I use it in Quad core and 8 core designs @ 4.4 GHz running to over 140 watts through a 1" square surface. Operating temps with an ambient of 86F/30C brings an operating temp of 38C under a heavy load. IOW it's very efficient. 

Getting ready to try a 5GHz plus.
To lap the surfaces, it is better to use lapping compound directly between the glass and surface to be lapped, working down to jewelers rouge that leaves a smooth shinny finish rather than emery cloth or paper, particularly when you get to the finer grades.. 

73

Roger (K8RI)



Regards David G0FVT

Sent from my iPad


On 12 Dec 2013, at 02:22, amps-request@contesting.com wrote:

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Today's Topics:

   1. Copper spreader, heatsink, boards (qrv@kd4e.com)
   2. Re: Copper spreader, heatsink, boards (qrv@kd4e.com)
   3. Another eBay Jem (Col. Paul E. Cater)
   4. Re: SSPA & Heatsink Compounds (Manfred Mornhinweg)
   5. Re: Another eBay Jem (donroden@hiwaay.net)
   6. Re: SSPA & Heatsink Compounds (dsolberg@wi.rr.com)
   7. Re: Another eBay Jem (Eddy Swynar)
   8. Re: Another eBay Jem (David Kirkby)
   9. Re: SSPA & Heatsink Compounds (Gary K9GS)
  10. Re: SSPA & Heatsink Compounds (Richard Solomon)


----------------------------------------------------------------------

Message: 1
Date: Wed, 11 Dec 2013 12:17:59 -0500
From: "qrv@kd4e.com" <qrv@kd4e.com>
To: Amps reflector <amps@contesting.com>
Cc: Radio_Swapshop2@yahoogroups.com, ham4sale@yahoogroups.com,
    forsale-swap <forsale-swap@mailman.qth.net>
Subject: [Amps] Copper spreader, heatsink, boards
Message-ID: <52A89E47.7090207@kd4e.com>
Content-Type: text/plain; charset=windows-1252; format=flowed

I have some amp parts that need a new home:

Copper spreader 5 1/2" x 15" & heatsink 8" x 15" from 1.2KW HF amp.

Three boards rated for 300w each, two complete with two MRF422's,
one w/o devices.

Should travel in a $15.30 Priority Mail? Large Flat Rate Board
Game Box 23-11/16" x 11-3/4" x 3"


--

Thanks! & 73, KD4E.com

David (never Dave) Colburn - Nevils, Georgia USA

Safe & Secure Search Engine: duckduckgo.com

Android for Hams: groups.yahoo.com/group/hamdroid
Creative Tech: groups.yahoo.com/group/ham-macguyver
Raspi Alternative: groups.yahoo.com/group/beagleboneblack/

Restored to design-spec at Heaven's gate 1Cor15:22


------------------------------

Message: 2
Date: Wed, 11 Dec 2013 12:28:20 -0500
From: "qrv@kd4e.com" <qrv@kd4e.com>
To: Amps reflector <amps@contesting.com>
Cc: Radio_Swapshop2@yahoogroups.com, ham4sale@yahoogroups.com,
    forsale-swap <forsale-swap@mailman.qth.net>
Subject: Re: [Amps] Copper spreader, heatsink, boards
Message-ID: <52A8A0B4.3070008@kd4e.com>
Content-Type: text/plain; charset=windows-1252; format=flowed

Accidentally left out the price on this.

Asking $150. (obo) plus the $15.30 shipping.


I have some amp parts that need a new home:

Copper spreader 5 1/2" x 15" & heatsink 8" x 15" from 1.2KW HF amp.

Three boards rated for 300w each, two complete with two MRF422's,
one w/o devices.

Should travel in a $15.30 Priority Mail? Large Flat Rate Board
Game Box 23-11/16" x 11-3/4" x 3"



--

Thanks! & 73, KD4E.com

David (never Dave) Colburn - Nevils, Georgia USA

Safe & Secure Search Engine: duckduckgo.com

Android for Hams: groups.yahoo.com/group/hamdroid
Creative Tech: groups.yahoo.com/group/ham-macguyver
Raspi Alternative: groups.yahoo.com/group/beagleboneblack/

Restored to design-spec at Heaven's gate 1Cor15:22


------------------------------

Message: 3
Date: Wed, 11 Dec 2013 14:26:46 -0500
From: "Col. Paul E. Cater" <paulecater@gmail.com>
To: Amps reflector <amps@contesting.com>
Subject: [Amps] Another eBay Jem
Message-ID:
    <CAJLRWYbHc1osuuwuYEmx1k1NzWghTG7z4PWxkEZ6W6W_9ccpAg@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1

Check out the tube in this prize-----

http://www.ebay.com/itm/Hallicrafters-HT-33B-Linear-Amplifier-Untested-/331083286378?&_trksid=p2056016.l4276

Paul
WD8OSU


------------------------------

Message: 4
Date: Wed, 11 Dec 2013 19:32:20 +0000
From: Manfred Mornhinweg <manfred@ludens.cl>
To: amps@contesting.com
Subject: Re: [Amps] SSPA & Heatsink Compounds
Message-ID: <52A8BDC4.8070800@ludens.cl>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

Paul,


I'm getting around to my 2 meter kilowatt SSPA.  My question is which of
the multitude of heatsink compounds do you recommend?  I have read some of
the comparisons mostly dealing with CPU cooling.  But, would like some
input from piratical experience.  The silver formulations seem to do a bit
better.


When I looked for data on these compounds, the best rated one I could
find was Arctic Silver 5. It's about twice as heat conductive as the
best ceramic-based compounds, according to its data sheet. But I haven't
yet measured whether those claims are true.

Between the different ceramic based compounds, there are some large
differences too. They are not all equal! I found differences up to a
ratio of ten between them! Check the specs and compare before you buy.


In addition, I am assuming that I want a layer of the stuff between the
copper heat spreader and the heatsink?


Yes. Assuming the spreader is large, and lies very flat against the
heatsink, a decent grade ceramic compound is good enough there - but a
better compound is always better! Between the transistors and the
spreader instead, really the best is soldering! Solder is about 8 times
better than the best silver particle compound. If it's not practical to
solder the transistors to the spreader (as is often the case), use the
best compound you can find. You need only a tiny quantity there.

And if your transistors are expensive, do the math about their cooling
BEFORE you build that amplifier! If they are cheap, or if you have a
free supply of them, you can use the empiric method and just see if they
survive... ;-)

Manfred

========================
Visit my hobby homepage!
http://ludens.cl
========================


------------------------------

Message: 5
Date: Wed, 11 Dec 2013 13:39:22 -0600
From: donroden@hiwaay.net
To: amps@contesting.com
Subject: Re: [Amps] Another eBay Jem
Message-ID: <20131211133922.10505gaar9haamp6@webmail.hiwaay.net>
Content-Type: text/plain; charset=ISO-8859-1; DelSp="Yes";
    format="flowed"

He Said ........

"Untested. I have not powered this unit nor do I know the last time
that it was powered."

Translation :

" Untested on Air.  I plugged it in and it blew the breaker off the
wall and set off all the fire alarms."  " I'll sell it for more than
it cost new, and you won't find a replacement tube".   ie : see "RARE
DESIRABLE AMP", and
"WONT LAST LONG"

Don W4DNR





Quoting "Col. Paul E. Cater" <paulecater@gmail.com>:


Check out the tube in this prize-----

http://www.ebay.com/itm/Hallicrafters-HT-33B-Linear-Amplifier-Untested-/331083286378?&_trksid=p2056016.l4276

Paul
WD8OSU
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps





------------------------------

Message: 6
Date: Wed, 11 Dec 2013 19:40:19 +0000
From: <dsolberg@wi.rr.com>
To: amps@contesting.com, Manfred Mornhinweg <manfred@ludens.cl>
Subject: Re: [Amps] SSPA & Heatsink Compounds
Message-ID: <20131211194019.VX0FQ.102469.root@cdptpa-web02>
Content-Type: text/plain; charset=utf-8

Manfred,

I have build several solid state amplifers, including a 1KW HF amp that I am 
currently using on a daily basis.  I use Artic Silver.  I found that it is 
really important to first of all have a flat surface between the copper heat 
spreader and the aluminum heatsink.  I have always had these surfaces milled.  
The milling cost more than the heatsink, but it is worth it.  Then put a very 
thin layer of Artic Silver between the copper heat spreader and the heatsink, 
and underneath the MOSFETS.  More is not better, use a line layer.  I use a 
roller to spread the Artic Silver.

Don
---- Manfred Mornhinweg <manfred@ludens.cl> wrote:

Paul,


I'm getting around to my 2 meter kilowatt SSPA.  My question is which of
the multitude of heatsink compounds do you recommend?  I have read some of
the comparisons mostly dealing with CPU cooling.  But, would like some
input from piratical experience.  The silver formulations seem to do a bit
better.


When I looked for data on these compounds, the best rated one I could
find was Arctic Silver 5. It's about twice as heat conductive as the
best ceramic-based compounds, according to its data sheet. But I haven't
yet measured whether those claims are true.

Between the different ceramic based compounds, there are some large
differences too. They are not all equal! I found differences up to a
ratio of ten between them! Check the specs and compare before you buy.


In addition, I am assuming that I want a layer of the stuff between the
copper heat spreader and the heatsink?


Yes. Assuming the spreader is large, and lies very flat against the
heatsink, a decent grade ceramic compound is good enough there - but a
better compound is always better! Between the transistors and the
spreader instead, really the best is soldering! Solder is about 8 times
better than the best silver particle compound. If it's not practical to
solder the transistors to the spreader (as is often the case), use the
best compound you can find. You need only a tiny quantity there.

And if your transistors are expensive, do the math about their cooling
BEFORE you build that amplifier! If they are cheap, or if you have a
free supply of them, you can use the empiric method and just see if they
survive... ;-)

Manfred

========================
Visit my hobby homepage!
http://ludens.cl
========================
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps




------------------------------

Message: 7
Date: Wed, 11 Dec 2013 16:38:15 -0500
From: Eddy Swynar <deswynar@xplornet.ca>
To: "Col. Paul E. Cater" <paulecater@gmail.com>
Cc: Amps reflector <amps@contesting.com>
Subject: Re: [Amps] Another eBay Jem
Message-ID: <075DA82B-A246-4DD9-9CF4-8035E5847D63@xplornet.ca>
Content-Type: text/plain;    charset=us-ascii



On 2013-12-11, at 2:26 PM, Col. Paul E. Cater wrote:

Check out the tube in this prize-----

http://www.ebay.com/itm/Hallicrafters-HT-33B-Linear-Amplifier-Untested-/331083286378?&_trksid=p2056016.l4276

Paul
WD8OSU



He's confusing "Ham radio ops" with "audiofools", judging by the price...

~73~ de Eddy VE3CUI - VE3XZ



------------------------------

Message: 8
Date: Wed, 11 Dec 2013 21:54:14 +0000
From: David Kirkby <david.kirkby@onetel.net>
To: Eddy Swynar <deswynar@xplornet.ca>
Cc: Amps reflector <amps@contesting.com>
Subject: Re: [Amps] Another eBay Jem
Message-ID:
    <CANX10hBUZad2aBsjnfv-uE3mRtKkzTOYFvCUikSpqoaxhzutPw@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1


On 11 December 2013 21:38, Eddy Swynar <deswynar@xplornet.ca> wrote:

He's confusing "Ham radio ops" with "audiofools", judging by the price...

~73~ de Eddy VE3CUI - VE3XZ


It is "or offer". I've sometimes made offers on eBay for a small
fraction of the asking price, and got them.  It is not uncommon to
find things over-priced by 10 dB, and occasionally 20 dB.

There was once a "free listing day" on eBay, and I was going to put a
milking stool on there. But I needed to get the auction on quick
before the free listing day ended, but did not know how much it was
worth. I put it on at ?1,000,000. Someone asked me why it was so
expensive, so I explained why.

Dr. David Kirkby G8WRB
http://www.vnacalibration.co.uk/
Economical & accurate VNA calibration kits.
Coefficients available for HP, Agilent, Anritsu, Rohde & Schwarz and
VNWA network analyzers.


------------------------------

Message: 9
Date: Wed, 11 Dec 2013 19:31:40 -0600
From: Gary K9GS <garyk9gs@wi.rr.com>
To: amps@contesting.com
Subject: Re: [Amps] SSPA & Heatsink Compounds
Message-ID: <52A911FC.7050006@wi.rr.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

Here is some good information:

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

There is a product called Arctic Silver that is very popular with
gamers/computer users.  I don't know much about it but it's widely
available from computer parts dealers like newegg.com.  Search under
"thermal grease" or "thermal compound".

For recommendations I'd look at manufacturer's website for the device
you're using.  They may have an app note.

I do know that you want to apply a uniform THIN coat.  More is NOT
better.  At work we use small rubber rollers to apply.  Almost like a
paint roller.




On 12/11/2013 10:15 AM, Col. Paul E. Cater wrote:
Greeting all,

I'm getting around to my 2 meter kilowatt SSPA.  My question is which of
the multitude of heatsink compounds do you recommend?  I have read some of
the comparisons mostly dealing with CPU cooling.  But, would like some
input from piratical experience.  The silver formulations seem to do a bit
better.

In addition, I am assuming that I want a layer of the stuff between the
copper heat spreader and the heatsink?

Paul
WD8OSU
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps


--


73,

Gary K9GS

Greater Milwaukee DX Association: http://www.gmdxa.org
Society of Midwest Contesters: http://www.w9smc.com
CW Ops #1032   http://www.cwops.org

************************************************



------------------------------

Message: 10
Date: Wed, 11 Dec 2013 19:21:59 -0700
From: Richard Solomon <dickw1ksz@gmail.com>
To: "amps@contesting.com" <amps@contesting.com>
Subject: Re: [Amps] SSPA & Heatsink Compounds
Message-ID:
    <CAC5FBO8murTS-+7ukC6F+zjuJxz+cAEBF3SGgKUfYYJUCyhL0Q@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1

I remember reading that the use of Heat Sink Compound between
the device (LDMOS) and the Cu Heat Sink was NOT recommended.
They require an extremely flat surface on the Heat Sink. The temp's
at that junction can be quite high.

It's use between the Cu and Al Heat Sinks though is another matter.

73, Dick, W1KSZ



On Wed, Dec 11, 2013 at 6:31 PM, Gary K9GS <garyk9gs@wi.rr.com> wrote:

Here is some good information:

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

There is a product called Arctic Silver that is very popular with
gamers/computer users.  I don't know much about it but it's widely
available from computer parts dealers like newegg.com.  Search under
"thermal grease" or "thermal compound".

For recommendations I'd look at manufacturer's website for the device
you're using.  They may have an app note.

I do know that you want to apply a uniform THIN coat.  More is NOT better.
At work we use small rubber rollers to apply.  Almost like a paint roller.




On 12/11/2013 10:15 AM, Col. Paul E. Cater wrote:

Greeting all,

I'm getting around to my 2 meter kilowatt SSPA.  My question is which of
the multitude of heatsink compounds do you recommend?  I have read some of
the comparisons mostly dealing with CPU cooling.  But, would like some
input from piratical experience.  The silver formulations seem to do a bit
better.

In addition, I am assuming that I want a layer of the stuff between the
copper heat spreader and the heatsink?

Paul
WD8OSU
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps

--


73,

Gary K9GS

Greater Milwaukee DX Association: http://www.gmdxa.org
Society of Midwest Contesters: http://www.w9smc.com
CW Ops #1032   http://www.cwops.org

************************************************

_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps



------------------------------

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------------------------------

End of Amps Digest, Vol 132, Issue 16
*************************************

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