Just finished up the Elecraft KPA500 solid state HF amplifier on Sunday, looking for AM miscreants to give me some signal reports, cawwmmn.

Just over 5 hours, in 100 degree barn heat.

Nice little box, just over 25lbs, quiet, interfaces very well with the K3, just the right amount of multi-color "glimmer-blinkies" on the front panel to let you know what is going on. Runs on 120 or 240. The right side panel heat sink keeps my coffee warm.

Photos to come once I get my Microsoft Frontpage to allow me to update my website, in the meantime, here are some stock photos.

Bruce, looks like you've had fun with another one. Congrats on your build.

'JRO, It's nominally 500 watts continuous, but will easily do 600 to 650 pep into a good match. The box is the same size as the K3 and is targeted at K3 owners as a plug and play means to just get comfortably over storm qrn.

I suspect it's robust enough to run, say 125 to 150 watts carrier AM, but it's really a SSB/DATA/CW amplifier.

From all I've read the KPA500 is a quality build, but very pricey/watt. I have a late model K3, kit built but I think for now I'll stop there. The K3 itself is certainly everything advertised and what 'UJR has shown in previous posts.

Elecraft is now working on a matching (same size) antenna matching box for the KPA500. That will be just as well built and pricey/watt.

The factory boys were asked on El's reflector why they didn't design the KPA500 for 1 KW. (two 500's through a combiner, etc.)  They simply answered, 'price point.'
I can see that 'point' since the 500 watt box is already pricey enough.

All considered, very nice products from Elecraft.

Nice stuff Bruce. 3 heat sinks would get you to 1500 watts but would require a second chassis. If K3 guys were smart they would design a kit that could be upgraded to higher power. A big box to fit 3 transformers and a second box to fit 3 amp modules. a combiner the filter designed to handle 1500 watts from the get go.  500 watts is a nice power level for SSB and CW.
Then you could use it to drive a QRO linear....

Thanks gents, still struggling to get my web updated.
I just contracted with someone to convert the entire website over to Wordpress format, much easier to deal with than the current 10 year old web software I've been using.

You guys nailed it on the tech side, small, compact, 26 lbs, quiet, syncs with the K3 and other radios, it's a nice piece. If I need more than 500 watts, conditions are prob lousy and I don't want to strain to hear them, big amp is still out in the barn.

Elecraft, some thoughts.
I love their products, yes, not as cheap as a MFJ Ameritron, but on the plus side it's not a MFJ Ameritron. :-) Company is highly ethical, has even wonderful to deal with, a model for what business should be like. Some stuff does come from China, a concern of mine, would rather pay more for US made, but such is life. Not to get off on a rant here, but we as a nation need a collective education of the value of rebuilding the manufacturing infrastructure in own country.

Back to Elecraft - What I really love is the build process, missed out on the Heathkit days, born too late, so this is my own halcyon days of radio. I've never been fortunate enough to have formal electronics training, so I appreciate that, like Collins, Elecraft has a very through explanation of the design and function of their products in their manuals. I love learning the how and why as much as building the kit.

You guys probably know that I did a number of full and painstaking restorations of old 1930s gear. That was fun and I loved it, but lately my business has really limited my free time, which is a good problem to have in a down economy, so the Elecraft kits let me get near immediate gratification, rather than working months over a project. I don't have to collect parts over a series of months, just place an order, a white box arrives in the mail, I disappear into the barn for a few days, and like magic a working radio appears.

I also needed a compact home station, Nancy has been encouraging me to set up a listening post in the house, so I don't disappear into the barn each Friday/Saturday night.
The Elecraft A Line station - K3 Transceiver, P3 Scope and KPA500 Amp fit perfectly on a writing desk in a spare bedroom. I do have buzzardly piece, the reproduction carbon filament Edison build in the desk light.

That's it for the moment, look forward to working some of you on the air with the new station!

73 Bruce