Well, I decided to get a separate amp.
These MOSFET amp boards are not as reliable as the older ones.
It's too much trouble for only 1-200 watts.
I still like the radio, all of the features I want.
I recommend the radio, but not the amp.
Bingo! The manufacturers already have enough problems getting these junk transistors, to be somewhat OK as a radio final. Expecting to be able to string another 54,000 of them together and make a bigger amplifier stage from junk, is ridiculous. Write them and tell them we are sick and tired of the DX-2457 being the only base radio you can buy, that doesn't stick you with having to rip out a worthless $300 amplifier stage, just to get back to a decent barefoot radio. There is a very good reason they refuse to take the junk amp off the radio, prior to sale.
Some places charge $1,000 for this new RCI base. If it only made a reliable 25 watts of clean RF output, they would struggle to fetch $700 for the radio. They have figured out they can charge as much as an entry level HF rig, as long as they can make more watts and provide familiar features. To do that, all they needed was a glorified CB board, switching supply and the approximate $30 in parts, that they have used to create 200 watts or more, for 200 days or less.
They are getting more than a 10 to 1 return on the money they spend on the added PA board and you can be sure, the profit margin is far less on the rest of the components. If they drop the cheap PA board or used real RF MOSFET's, they would lose more of their profit margin, than they are willing to simply give up. You have to speak with your wallet and not just your mouth in this case.
STOP BUYING THEM. Force every high power export to sit on the stock shelf indefinitely. Until such time as they are willing to replace four junk output transistors (8 in other radios), with a matched pair of the current Mitsubishi 100 watt RF MOSFET's, that HF radio manufacturers knew enough to switch over to a decade ago! In bulk, those parts might cost them $40, for the pair needed in each radio. Rather than eat it, they'll charge you double. To be frank, I'd welcome that over what they are trying to get away with on unsuspecting customers today.
My first employer once told me, "We can legally charge the customer whatever we want! As long as we are honest about what we are selling them in advance." That led to having to identify the common fuse, as "the overload protection device". So keep in mind, there are literally hundreds of different 100 watt mobile radios being manufactured today, that use reliable RF output stages. The ONLY place that hasn't flat out rejected the use of inferior switch mode MOSFET's in linear amplifiers, is the illegal 11 meter market...
I've got to say, some of these radios are just filthy too. I don't know if something happens when one switch mode FET starts leaking, or if the bias is just set way off. In any event, the amount of spectrum they can take up, once you add another amplifier stage behind it, is amazing! They're barely down 10db, when you're 10 Khz. away. Every amplifier stage you add after the radio, typically adds at least another 10db to those problems. If we can't get people to be concerned about spectral purity, at least demand some reliability for your money.