I've built a few kits before. Certainly never anything so complex. But I am pretty experienced with soldering and as an electronics technician, so I dove right into it.
There is an awful lot of soldering. If you are going to build this kit, do yourself a favor and invest in a good soldering station, like a Weller. The el-cheapo temperature controlled irons don't work worth a darn, I know from experience. A Panavise is a really good idea as well. The alligator clips on the helping-hands will chew up your PCBs.
Winding the toroids was fast and easy. I don't know what everybody is whining about. You must have awfully fat fingers if you can't thread a wire through a toroid.
Aligining the filters is tricky at best. This was probably my least favorite part of the build. I used a high-accuracy HF RF signal generator and a PC spectrum analyzer program to do it. You could ballpark it by ear but I wouldn't want to.
Overall, the build was complex and took a long time. But I made very few mistakes and they were easily corrected. It wasn't difficult, actually quite straight forward, but very time consuming.
I built this radio because of the receiver. Compare the specs. It's got one of the highest performance receivers on the market. My on air experience confirms that this receiver doesn't bat an eyelash at a band chock full of kilowatts. It's a big gun contest radio trapped in a pea-shooter's body. On air testing in the ARRL Sweepstakes confirms that this receiver works great. It's highly selective and doesn't de-sense in the presence of strong adjacent signals. Other than maybe the K3, it's probably the best contest and DX receiver on the market.
Not much needs to be said about the transmitter. It's 15W. You either like QRP or you don't. I don't. I'm going to build the KPA-100 hundred watt power amplifier ASAP. I do get good audio reports which IMO is all that really matters in a transmitter.
I've heard some complaints about fit and finish. I think it's up to par with most other rigs on the market. Maybe just a tad behind. The POTs are a little flimsy, I worry about their long term survival in a rough environment. But they're obviously user serviceable hi hi. The mechanical construction of the chassis is a bit different but seems rugged enough to me.
My only real mechanical complaint is the crazy way the finals are heat sinked, making removal and installation of that one panel a very fiddly operation with a lot of small parts to get lost. One of these days I'm going to glue all those parts together to minimize the chances of any one getting lost
As for usability it's great. It has pretty much all of the buttons and knobs I want right on the front. I very rarely have to delve into the menus. Compare this to my FT-897, I'm almost constantly scrolling through different button functions during normal ops.
My only usability complaint is the dedicated digital voice recorder buttons. I wish I could reassign them since I have no intention of installed the DVR module. If I want DVR I'll use my PC. Perhaps this could be fixed in firmware.
- SWR metering in the base kit would be nice. It is provided with the KPA-100 module and also I assume in the ATU modules.
- Mic gain. I know it's supposed to be automatic. I still like to adjust it myself. Maybe there is a way that I'm not aware of.
- Remote front panel. I really miss this. As small as it is, mounting it in a modern vehicle is not trivial. None of the mobile rigs have receivers anywhere close to the K2.
- VHF at a reasonable cost
This radio is deceptively expensive. You should seriously consider your priorities and add up the total cost of the base rig plus all of the modules you intend to build before purchasing it including transverters. If all you care about is QRP CW on HF, then it's probably a great deal. Add SSB, it's still pretty reasonable. Add the 100W amp and the DSP and noise blanker and you're getting up to about $1300, which is still reasonable considering how awesome the receiver is. Yes you could almost buy an Icom 746Pro for that price, but no you would not be getting the same radio. The Icom is about bells and whistles. The K2 is about performance. It's like comparing a Ferrari to an Escalade. They both go fast but one has a lot more buttons and the other can drive circles around the first. Do you like making contacts, or do you like pushing buttons?
Do you want to work VHF? If so figure another $350 to $400 for an Elecraft transverter for each band you want to work. Plus $100 for the transverter interface board. Now the little bugger starts to get a heck of a lot more expensive than many other radios with similar features. It will probably perform better than just about any other radio on the market, but if you just want to get on VHF and aren't serious about winning the contests, maybe a K2 isn't the rig for you.
The K2 is a premium product with premium receiver performance at a premium price that goes up quickly depending on what capabilities you want to add. The build process is long but rewarding. The result is a contest winning, DX working HF ham radio with one of the top receivers on the market and lots of great features packed into an efficiently compact unit that you can fix yourself.