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KX2 Heatsink

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Kevin - K4VD

KX2 Heatsink

From a recent post:

"We have been told by people running the rig in digital modes at 10W the
unit will thermal down after a few transmit cycles"

I understand the KX3 also had an early issue with heatsinks that was
corrected in time by the company making the aftermarket heatsink
unnecessary I think? I wonder if Elecraft has acknowledged the issue and is
correcting it for the KX2 also?

It seems odd to me that an issue like this would go unmentioned and
unaddressed by Elecraft.

73,
Kev K4VD
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rich hurd WC3T

Re: KX2 Heatsink

I had thermal warnings on my KX3 with WSPR at 0.1 watt. 60% duty cycle,
however.

On Sun, May 14, 2017 at 12:19 PM Walter Underwood <[hidden email]>
wrote:

> First, read the specifications. They are on page 54 of the latest KX3
> manual.
>
> " 5 W or less recommended for high-duty-cycle modes (FM, AM, DATA). Power
> will automatically be reduced if PA temperature or current limits are
> exceeded.”
>
> A larger heatsink was introduced a couple of years ago. The serial numbers
> for the new heatsink are listed on the mods page.
>
> http://www.elecraft.com/order_form_parts.htm#kx3 <
> http://www.elecraft.com/order_form_parts.htm#kx3>
>
> Description and instructions include this: "The enhanced heat sink is
> thicker than the original and wraps around the bottom of the KX3 as shown
> in Figure 1. The additional mass and area of this heat sink provides as
> much as twice the operating time at full power before the KX3’s protective
> circuitry automatically reduces the power to 5 watts."
>
>
> http://www.elecraft.com/manual/E740254%20KX3HSMDKT%20Heat%20Sink%20Installation%20rev%20A.pdf
> <
> http://www.elecraft.com/manual/E740254%20KX3HSMDKT%20Heat%20Sink%20Installation%20rev%20A.pdf
> >
>
> For digital modes that require a lot of headroom and linearity (PSK31),
> I’d probably stick with 5 W.
>
> wunder
> K6WRU
> Walter Underwood
> CM87wj
> http://observer.wunderwood.org/ (my blog)
>
> > On May 14, 2017, at 8:05 AM, Kevin - K4VD <[hidden email]> wrote:
> >
> > From a recent post:
> >
> > "We have been told by people running the rig in digital modes at 10W the
> > unit will thermal down after a few transmit cycles"
> >
> > I understand the KX3 also had an early issue with heatsinks that was
> > corrected in time by the company making the aftermarket heatsink
> > unnecessary I think? I wonder if Elecraft has acknowledged the issue and
> is
> > correcting it for the KX2 also?
> >
> > It seems odd to me that an issue like this would go unmentioned and
> > unaddressed by Elecraft.
> >
> > 73,
> > Kev K4VD
> > ______________________________________________________________
> > 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
> > Message delivered to [hidden email]
>
> ______________________________________________________________
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>
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--
73 (or 72 for the QRP folks),
Rich Hurd / WC3T
Northampton County RACES
EPA-ARRL Public Information Officer for Scouting
Latitude: 40.761621 Longitude: -75.288988 Grid: *FN20is*
40°45.68' N 75°17.33' W
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wayne burdick

Re: KX2 Heatsink [which is entirely sufficient for typical operation]

Administrator

In reply to this post by Kevin - K4VD

Hi Kevin,

We have shipped many thousands of KX2s, and in all that time I have seen only a few comments asking about additional heat sinking.

The KX2’s thick right side panel is thermally integrated with both the top and bottom cover. This results in heat sinking that is entirely adequate in all modes at full power, even from a 14 volt external supply. When running from internal battery (11 V), heat dissipation is further reduced for a given power level.

To put a rough number on this: I just ran my KX2 at 10 watts key-down in CW mode, into a dummy load, while watching the PA temperature (using the DISP switch function). It took well over 7 minutes for the temperature to reach the limit (63 C), at which point power was reduced automatically to 5 watts. If you persisted in operating key-down, the radio would eventually exit transmit mode. Starting temperature was 25 C (shack ambient).

Additional heat sinking might be desirable if you’re going well beyond “typical” operation: e.g., trying to run full power key-down for many minutes at a time, repeatedly, in a hot car or in direct sunlight. In that case, you have other options besides using supplemental heat sinking: reduce power, run from a lower supply voltage (like the internal battery), move into the shade, roll down the car windows, etc.

But for the overwhelming majority of our customers, the KX2’s thermal design is completely up to the task. Note that the heat sinking is intentionally designed to heat up the right end of the enclosure, so that when using the rig like an HT (holding the non-antenna end), you’ll barely feel any increase in warmth.

73,
Wayne
N6KR

> Kevin - K4VD wrote:
>
> From a recent post:
>
> "We have been told by people running the rig in digital modes at 10W the
> unit will thermal down after a few transmit cycles"
>
> I understand the KX3 also had an early issue with heatsinks that was
> corrected in time by the company making the aftermarket heatsink
> unnecessary I think? I wonder if Elecraft has acknowledged the issue and is
> correcting it for the KX2 also?

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Kevin - K4VD

Re: KX2 Heatsink [which is entirely sufficient for typical operation]

Thanks Wayne. I bought the heat sink for the KX3 and found it wasn't needed
for the way I operate. Seems the same for the KX2. Normal conditions don't
require additional heatsinking. Extreme conditions might.

73,
Kev K4VD

On Sun, May 14, 2017 at 12:55 PM, Wayne Burdick <[hidden email]> wrote:

> Hi Kevin,
>
> We have shipped many thousands of KX2s, and in all that time I have seen
> only a few comments asking about additional heat sinking.
>
> The KX2’s thick right side panel is thermally integrated with both the top
> and bottom cover. This results in heat sinking that is entirely adequate
> in all modes at full power, even from a 14 volt external supply. When
> running from internal battery (11 V), heat dissipation is further reduced
> for a given power level.
>
> To put a rough number on this: I just ran my KX2 at 10 watts key-down in
> CW mode, into a dummy load, while watching the PA temperature (using the
> DISP switch function). It took well over 7 minutes for the temperature to
> reach the limit (63 C), at which point power was reduced automatically to 5
> watts. If you persisted in operating key-down, the radio would eventually
> exit transmit mode. Starting temperature was 25 C (shack ambient).
>
> Additional heat sinking might be desirable if you’re going well beyond
> “typical” operation: e.g., trying to run full power key-down for many
> minutes at a time, repeatedly, in a hot car or in direct sunlight. In that
> case, you have other options besides using supplemental heat sinking:
> reduce power, run from a lower supply voltage (like the internal battery),
> move into the shade, roll down the car windows, etc.
>
> But for the overwhelming majority of our customers, the KX2’s thermal
> design is completely up to the task. Note that the heat sinking is
> intentionally designed to heat up the right end of the enclosure, so that
> when using the rig like an HT (holding the non-antenna end), you’ll barely
> feel any increase in warmth.
>
> 73,
> Wayne
> N6KR
>
>
>
> > Kevin - K4VD wrote:
> >
> > From a recent post:
> >
> > "We have been told by people running the rig in digital modes at 10W the
> > unit will thermal down after a few transmit cycles"
> >
> > I understand the KX3 also had an early issue with heatsinks that was
> > corrected in time by the company making the aftermarket heatsink
> > unnecessary I think? I wonder if Elecraft has acknowledged the issue and
> is
> > correcting it for the KX2 also?
>
>
>
>
>
>

kevino z

Re: KX2 Heatsink [which is entirely sufficient for typical operation]

I like the way the way the VE7FMN heat sink I bought for my KX3 looks. Now that the PAs are on the side of the KX2, I just don't feel the same about the appearance of the heat sinks I've seen for it. Kind of look lopsided.

-Kevin (KK4YEL)

-----
The problem with the world is that the intelligent people are full of doubts, while the stupid ones are full of confidence.

On May 14, 2017, at 16:02, Kevin - K4VD <[hidden email]<mailto:[hidden email]>> wrote:

Thanks Wayne. I bought the heat sink for the KX3 and found it wasn't needed
for the way I operate. Seems the same for the KX2. Normal conditions don't
require additional heatsinking. Extreme conditions might.

73,
Kev K4VD

On Sun, May 14, 2017 at 12:55 PM, Wayne Burdick <[hidden email]<mailto:[hidden email]>> wrote:

Hi Kevin,

We have shipped many thousands of KX2s, and in all that time I have seen
only a few comments asking about additional heat sinking.

The KX2’s thick right side panel is thermally integrated with both the top
and bottom cover. This results in heat sinking that is entirely adequate
in all modes at full power, even from a 14 volt external supply. When
running from internal battery (11 V), heat dissipation is further reduced
for a given power level.

To put a rough number on this: I just ran my KX2 at 10 watts key-down in
CW mode, into a dummy load, while watching the PA temperature (using the
DISP switch function). It took well over 7 minutes for the temperature to
reach the limit (63 C), at which point power was reduced automatically to 5
watts. If you persisted in operating key-down, the radio would eventually
exit transmit mode. Starting temperature was 25 C (shack ambient).

Additional heat sinking might be desirable if you’re going well beyond
“typical” operation: e.g., trying to run full power key-down for many
minutes at a time, repeatedly, in a hot car or in direct sunlight. In that
case, you have other options besides using supplemental heat sinking:
reduce power, run from a lower supply voltage (like the internal battery),
move into the shade, roll down the car windows, etc.

But for the overwhelming majority of our customers, the KX2’s thermal
design is completely up to the task. Note that the heat sinking is
intentionally designed to heat up the right end of the enclosure, so that
when using the rig like an HT (holding the non-antenna end), you’ll barely
feel any increase in warmth.

73,
Wayne
N6KR

Kevin - K4VD wrote:

From a recent post:

"We have been told by people running the rig in digital modes at 10W the
unit will thermal down after a few transmit cycles"

I understand the KX3 also had an early issue with heatsinks that was
corrected in time by the company making the aftermarket heatsink
unnecessary I think? I wonder if Elecraft has acknowledged the issue and
is
correcting it for the KX2 also?

______________________________________________________________
Elecraft mailing list
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Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

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