vitvool1,
no disrespect towards you but the b150 is class C and sounds poor on ssb, the late model b150 uses the same board as the rm kl200 which also sounds poor,
i know many people will give you a good audio report but that tells me they are either just been polite or they dont have a clue what ssb should sound like,
some b300p's have input padding or to be more correct a series 2w resistor between the relay and the rf input to the power sellector board, i guess they cant be bothered using a proper input pad,
a couple of extra resistors of suitable watt rating would be too much to expect from them,
some have a wire jumper in place of the resistor,
some use 455's some use 1446's either way they are usually flat balls out on a wattmeter with less than 10w fm drive but not always,
that 10w fm they recommend will eventually burn the power setting resistors if used on setting 1-5 and the feedback resistors if used on setting 6,
zetagi put a sticker on the amp telling you not to input more than 5w on setting 6 which is sound advice for longevity but you wont get near full output,
it also leads you to believe that 5-10w fm is ok on settings 1-5,
5w on setting 1-5 is about max safe input without damaging the resistors, input 10w on settings 1-5 and they burn, you end up with all power settings giving the same output with any drive level,
i have people bring them for repair and the input att resistor has got so hot it unsolders itself and is floating around inside burnt to a crisp, the same goes for the feedbacks they are usually brown or burnt and on several occasions floating loose inside, the 10ohm base emitter resistor can also go brown,
the versions with the input resistor and 1446 transistors are much less prone to the rest of the amp burning up and in most cases replacing the resistor with a higher wattage version will have the amp working as usual,
with mrf455's your less likely to get away with overdriving the amp,
versions with the jumper wire are usually in a much worse state when they arrive at my door,
i have on several occasions had to etch a new power sellector board because its burned black and the traces peeling off,
the sd1446 transistors will often stand more drive than the rest of the amp,
most of the above also applies to the kl351p/kl400/kl500 / zetagi b550p/ and the 28volt b750/b1200, its not unusual to find feedback resistors floating around inside a b750 and a burnt resistor on the output combiner,
zetagi and rm is italian for lottery,
you never know what you are getting or what drive it needs for full output and what that full output will be untill you look whats inside and test it on a decent wattmeter and dummyload,
about the only thing you can say for sure is they both talk bollocks with their input and output ratings,
following their guidelines will get you burnt components dry solder joints and charred circuit boards but the transistors may survive,
keep drive levels down especially on fm, fit a decent fan and they can last for years trouble free,
if you dont want to adjust the radio you need to make an input attenuator as freecell suggested using none inductive resistors that can handle the input power without getting overly hot, fit it between the relay and the trace that runs to the power sellector board after removing the resistor or wire jumper thats in there now, there are a few ways to do it, this may help.
http://www.raltron.com/cust/tools/t_attenuator.asp
