The Tentec R4020 has semi break-in. It works well. I bought one of these little QRP rigs from Tentec. My first QSO with it was on 20m and I worked a British station who answered my CQ. The second contact was with a fellow in Minnesota. For its price, the radio has a ton of features. Your worry about it not being up to par for long transmissions is not an issue. I found the rig quite robust in every respect. Of course, I was using a 3-element SteppIR yagi at 60 feet with the R4020 so I had no trouble cruising the band and working just about everyone I called. I did find that when connected to the yagi, the rig's front end was a bit overloaded and there was some mixing going on. I could hear some shortwave broadcast signals mixed in with the strongest CW signals but this is ONLY because of the big antenna. This radio is primarily built for portable use and with a more modest antenna, the mixing issue wouldn't be there. When I activated the built-in attenuator the front-end issue ceased. But I did feel like there was a bit too much attenuation -- I would have preferred a bit less.
The radio, of course, is made in China. The manufacturer there now has a website. It's www.youkits.com
. There, the company says the production of the HB-1A 3-band rig -- the same radio Tentec now sells as two two-band versions -- is out of production. So, you have to buy Tentec's version. In the meantime, the Chinese manufacturer is working on a 4-band CW QRP rig to take the place of the HB-1A. He is also producing now the TJ6A, a 6-band, 10 watt SSB/CW transceiver that sells for about $300 assembled, $245 as a kit. They're taking orders. Not sure if they have shipped any. Lots of photos on the website, schematics, etc. The company is also working on a all-band, all-mode HF backpack transceiver, they say. And they have just announced their HF 2 KW linear amp.
If you want to send CW from a keyboard with the R4020, I think you will have to use a mono mini-plug. The rig has a built-in keyer and is built primarily with the idea that you will use paddles with it. The manual says you can use a straight key -- and turn off the built-in keyer. An external keyer would function like a straight key as far as the radio is concerned.
I also have an FT-817ND. It has a better receiver and a ton more features but at two and a half times the price. The R4020 is impressive for a so-called trail friendly radio and offers many features for the money. Truthfully, few people would probably buy one of these and attach it to a big yagi like I did so the front-end issue I had probably wouldn't be an issue for most folks.
73, dave, N4KZ