I have a kl 203p, i think it's the same thing as a ad-203 just external and has a housing that doubles as a heatsink, it is so small that it could be bolted right on top of the radio, granted it would cover most of the speaker... I think I paid like $65 while it was on sale. Good little amp for my experiments. I have heard this 10 meter amp will key on 11 meters but I cannot & will not confirm.
The speaker is removed from the radio and the amp is mounted on the lid where the speaker was.
Yes it will key on 11 meter.
I wonder if this amp is going to oscillate on me or give me problems, the relay only clicks to activate the unit when the radio is keyed. Has a nice pre-amp too if you want to hear the noise floor louder. Sometimes the pre-amp can help pull in a distant station that otherwise would not have been heard.
All amplifiers can and will oscillate under the proper conditions.
The pre-amp is not selective and amplifies everything including noise. I have personally have not seen it be of any benefit.
If its for a cb the carrier will have to be lowered, one could add a diode inline to the one leaving the modulation transformer if it's that type of radio (Most cobra mobiles). Also check your countries regulations first, I cannot recommend something that may get you in trouble...