[Amps] 4CX1500 class AB1 vs. AB2

[Tom W8JI]

> This seems strange to me.  I have a IC775DSP that was used 
> with an Alpha 87A
> for several years.  There was never a problem like you 
> have described.  Was
> this because of amp design that absorbed the spikes?  ALC 
> has never been
> used with this amp.

The rig had severe overshoot into a dummy load, antenna, 
amplifier, or anything else placed on the output. I'm not 
alone in seeing that problem with 775's, and many (if not 
most) rigs have that problem.

http://www.nitehawk.com/sm5bsz/dynrange/dubus205/dubus205.htm

It could be the 87A protection response is slow enough to 
ignore the problem.

73 Tom