WOW!!
I just sat down in the USS Seawolf (SSN 21)s radio room and got a crash course in AM radio design from two 20+ year radio chiefs including one who worked in the maintenance facility building and repairing amplifiers for about 6 years! (for those of you who don't know the Seawolf is a submarine.) Basically I was in guys like DTD, Davemade and AM powers' Valhalla. There was more power right next to me than I would ever need. Oh ya, it doesn't hurt that there transmitters typically work with a 5 Hert bandwidth.
So anyways, they showed me the amp that is closest to an amp apropriate for CB/SSB use and it was actually really close to what I've been thinking of. The actual design is of course classified but the points of intrest to me I can talk about and see what you think.
First, they both agreed that 100% modulation is it. There is no more and nothing else.
Second, about design, There transmitter is totally isolated from the amp/s, I mean completly, no exciter or nothing in the same rack. I have been thinking that would be a good way to go. Remove any final stage from the radio and run low impedence line to the amp (probably RCA,) then arrange the amp as a 1x2 only instead of the first transistor acting as an IPA, have it act as the exciter and intruduce the information to the amp in an enviroment completly isolated from the source in order to eliminate RF coming from the source. My power supply will deliver a very narrow band voltage at the best impedance for the amp section.
Oh ya, check this out. They say working on antennae SWR is sort of putting the cart before the horse. They use variable impedence power supplies to tune the amp exactly to the frequency they will transmit on, then they tune for SWR wich is much easier if the amp is set up corectly. I obviously don't have acess to that technology put if you think about it, it shouldn't be all that hard to build an electronically variable impedance matcher that is driven by either a frequency counter or the PLL to adjust for the channel your transmitting on. I won't try that for a while it just looks really really cool, and works great.
Third, some of there amps are just like the new car audio class D mono amps. They drive full power, no modulation. Then the information is introduced after the waveform is built. I have no idea how to do that but they say by not combining the power and information you eliminate distortion. There information amps are class A that are introduced to the class D power. I guess you can imagine how it sounds.
So, absolutly no wraps of wire through broadband transformers ( they don't think to highly of them,. ) I didn't get to see how they impedance match to the antennae, I guess I'll just have to wait untill Monday.
Anyways, thanks for all your help and if you have any comments on my isolation idea I'd love to hear it.
Thanks again
Ron