How clean is the output on these devices? Are you going to make a big spectral mess over the air when you bring it up to 50-100w, assuming you have a clean linear?
It does not have any output filtering, so it does needs to have low pass filters added to the output. You will find the 2nd and 3rd harmonics will exceed the legal limits (-30db I think) as they get amplified without bandpass filters added.
BTW, the proper place to put the bandpass filters is AFTER THE AMP. Any good quality amp will have proper bandpass filters builtin to its output, only the cheap poor quality CB amps will not have filters built in.
Also, keep in mind most amps require a higher driving wattage than the RXTX can put out, an amp has to be specifically designed for being driven with low power/qrp rigs.
Filters and amplifier kits from these guys are popular with the softrock community:http://site.hfprojectsyahoo.com/homehttp://www.hfprojectsyahoo.com/ http://www.communication-concepts.com/
I always liked this kit as a possible addition to an RXTX. It has built in filters, and its designed to be driven from very low power like the RXTX.http://site.hfprojectsyahoo.com/hf_packer-amp