Look for, "Amplified Communications Speaker" --
Even RadioShack still sells one example:
http://www.radioshack.com/product/index.jsp?productId=4371942Of course there are other brands out there as well.
You might also try Amplified Speakers for PC, save some money, they are typically stereo, but you can use one side for one rig or use both channels to amplify two rigs separately L and R -- with a proper adaptor Y cable for the input.
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