One reply I have is that it's really not just as simple as adding band-selectable filters (which is what I assume you meant by "auto-tuner board"). While I'm an advocate of doing exactly what you suggest, having built a couple sets of filters to use with CB-style amps, it doesn't equate to the same quality of design that even Ameritron amps demonstrate. One major difference is in the biasing. Texas-star uses a brute-force biasing method that utilizes a clamping diode and a big resistor to deliver voltage and current to the transistor's bases. While it does work up to about the 100W level with acceptable results, this method has some major drawbacks in that the bias voltage sags on signal peaks, causing the amp to fall back into class C territory. This method is also sensitive to variations in supply voltage, so if the voltage source feeding the amp drops below 13.8V the bias voltage drops also. What is needed is regulated bias, where a voltage regulator is used to provide constant bias voltage to the tranistors. Also, Texas Star doesn't include temperature tracking of the bias, which is important to help avoid thermal runaway during operation.
Also, the feedback networks in the Ameritron design are superior to the capacitor/resistor feedback loop used by Texas Star and most other CB amp manufacturers as they include an inductive element in the form of a transformer that samples the output for return to the input and helps level the gain of the amp across it's full range.
There are also much better designs out there than Ameritron, but not from any CB amp manufacturer I know of, at least none without some serious modifications.
Also, the feedback networks in the Ameritron design are superior to the capacitor/resistor feedback loop used by Texas Star and most other CB amp manufacturers as they include an inductive element in the form of a transformer that samples the output for return to the input and helps level the gain of the amp across it's full range.
There are also much better designs out there than Ameritron, but not from any CB amp manufacturer I know of, at least none without some serious modifications.