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 bo

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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

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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 trans

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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

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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

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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 adv

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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 fa

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Re dummy load. First measure it with an ohm meter. It should measure 50 ohms +/- 5% or better. Then measure it with your antenna bridge from the lowest to highest frequency you intend to use. An MFJ-2

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I have only received my KPA1500 recently, But I decided to put it through the paces with the K3S being the exciter. I found that into a Cantenna Dummy Load that has not been tested for 50 Ohm impedanc

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That display should be indicating OUTPUT power. I suggest you use an external meter of known accuracy and a 50 ohm dummy load of known accuracy. Measure both the input to the amp from the transceiver

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Adrian, I mean 1500W as indicated on the led power bar whatever that means - input / output. 73, Jim K7EG

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FCC max gain for amps is 15 dB. Ray W8LYJ

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I think that was a typo - I'm sure he meant 1500 watts out.

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Jim, Can you clarify what you mean by 1500 watts input ? I thought that 1500 watts was the output figure on the amp with that drive, and that the input value would be much higher allowing for efficien

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About 25 - 30 watts for 1500 watts input. Jim K7EG

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Sounds friggin' awesome! ______________________ Clay Autery, KY5G (318) 518-1389 On 02/02/20 08:53, John Canfield wrote:

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Good. 35 watts of drive from my K3 drives my Alpha 8410 to legal limit power. Chris NU1O

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Thanks again guys and thanks Bob for the numbers. I wasn't making notes when tracking drive vs. output power - just a fairly gross report of what I was seeing. The entire reason for my question is my

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In doing the math, 28 watts to 1500 watts is 17.3 dB gain, while 5 watts to 150 watts is 14.8 dB gain, and 5 watts to 200 watts is 16.0 dB gain. The point is the amp appears to be operating normally w

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Yes the K3 is cleanest around 35 watts. No I never tested it at 30 watts vs. 35 watts, etc. I doubt you could tell the difference. Rob, NC0B

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