KPA1500 Temperature Management #kpa1500


David Mackey
 

I just added a KPA1500 to the shack, and  I am unsure about how much I should worry about temperature management. I know the maximum specified in the specs is 110C, but that does seem very high. The fans kick in about 40C and start ratcheting up at about 50c. I've had issues with LDMOS devices in the past so I am a bit nervous to just letting things increase to "see what happens". Can anyone give some longer term user advice as to their experience, and at what point things stabilize? The ambient temp here in the shack is not high, about 60-75F.

I looked around for a KPA1500 group, but couldn't find one. Let me know if this is the wrong venue.

Thanks
73 Dave K1KA


Jim Brown
 

On 8/30/2021 9:20 AM, David Mackey wrote:
I just added a KPA1500 to the shack, and  I am unsure about how much I should worry about temperature management. I know the maximum specified in the specs is 110C, but that does seem very high. The fans kick in about 40C and start ratcheting up at about 50c. I've had issues with LDMOS devices in the past so I am a bit nervous to just letting things increase to "see what happens". Can anyone give some longer term user advice as to their experience, and at what point things stabilize? The ambient temp here in the shack is not high, about 60-75F.
K6XX, a neighbor and good friend, is the engineer for Elecraft tasked with putting both of Elecraft's amps into production. We are both contesters, and I do a lot of WSJT modes on 6M and 160M. Bob advised me to accept the default settings for the fan, and let the firmware take care of the devices. I run legal limit on all bands but 6M, where I limit power to about 1.1kW, and a bit lower for long TX modes on 6M like Q65 120 sec.
I looked around for a KPA1500 group, but couldn't find one. Let me know if this is the wrong venue.
The best venue is the list set up by Elecraft, which both Wayne and Eric read. Sign up on the website.

73, Jim K9YC


K9MA
 

In CW contest operation, I've never see the temperature get much above 60 C. I have, however, tested the fans at maximum speed. You will know if they ever reach that speed, and there better not be any loose papers lying around.

73,
Scott K9MA 

On 8/30/2021 1:56 PM, Jim Brown wrote:
On 8/30/2021 9:20 AM, David Mackey wrote:
I just added a KPA1500 to the shack, and  I am unsure about how much I should worry about temperature management. I know the maximum specified in the specs is 110C, but that does seem very high. The fans kick in about 40C and start ratcheting up at about 50c. I've had issues with LDMOS devices in the past so I am a bit nervous to just letting things increase to "see what happens". Can anyone give some longer term user advice as to their experience, and at what point things stabilize? The ambient temp here in the shack is not high, about 60-75F.

K6XX, a neighbor and good friend, is the engineer for Elecraft tasked with putting both of Elecraft's amps into production. We are both contesters, and I do a lot of WSJT modes on 6M and 160M. Bob advised me to accept the default settings for the fan, and let the firmware take care of the devices. I run legal limit on all bands but 6M, where I limit power to about 1.1kW, and a bit lower for long TX modes on 6M like Q65 120 sec.

I looked around for a KPA1500 group, but couldn't find one. Let me know if this is the wrong venue.

The best venue is the list set up by Elecraft, which both Wayne and Eric read. Sign up on the website.

73, Jim K9YC








-- 
Scott  K9MA

k9ma@...


Steve Fox
 

I can only speak for my little KPA500, but the first few weeks I had it, the temps would rise to about 59C on digital and the unit would make small thermal contraction noises at the end of tx. However, after a few weeks of use I’m seeing a high of 55 tops, and no more cooling noises. FWIW.

Steve
KA4FOX


wb6bee
 

Making a couple of observations.

1.  I run the KPA 1500 at about a KW on lower bands and full power on higher bands.   I am a long winded CW operator so generally get to fan level three during most transmissions.   I let the factory default settings mange the fans.

2. That being said, there is a program out there called Fanticipator that gives the operator some fan management tools to use if the want to do things like having the funs run longer or at a minimum speed when operating.

3.  My shack is on the west side of an un-airconditioned house.   Lots of glass.   Summer afternoons can push 80 plus degrees in the shack.   I remotely located my amp in a cool area below the shack.  I have USB and Ethernet cables running from the K3s to the amp.   I can use the KPA 1500 utility, the Elecraft KPA 1500 remote program or Fanticipator to manage the remote amp.   In the remote location, the amp runs significantly cooler and I don't have any fan noise to deal with.  I like using Fanticipator for remote control because it has a small monitor footprint and, uniquely, keeps the power out and swr reading on the display so you can look at them after you transmit.

4.  Personally, I find the regular Elecraft forum difficult to read.   It doesn't put messages into threads like Groups or Google.



Don
WB6BEE


David Mackey
 

Thanks all for your suggestions and replies. I am more comfortable now accepting Elecraft’s technology to protect the amp from over heating. One change here, I relocated the amp to provide much better air flow on top. The temp seems to stabilize more rapidly in the 50-65C range. A previous amp needed air flow behind so it was under a shelf. I am also setting the starting fan speed higher when operating via remote and out of earshot.

73 Dave K1KA


Scott Townley
 

For what it's worth, I run my KPA1500 "stock" (no fan modifications or management).  On some of the 6 meter openings this summer, I'd be transmitting 15 on /15 off for over an hour straight.  At full boat, I never saw the heatsink temperature exceed 60°C.  That's a lot of thermal headroom even if the 110°C rating is generous.