Comb Generators

Only from Jeff Beck's song, Guitar Shop, "Comb generator for stereoizing a mono source!"

http://www.directindustry.com/industrial-manufacturer/comb-generator-78453.html?gclid=CNTF87_V7IwCFQxFZwodWkgslw

and

http://www.picosecond.com/product/category.asp?pd_id=22

or just google: "comb generators"

Yeah the advice to Google it is good, lots of people make them.

Usually just a fast diode (Schottky), often connectorized and maybe with some matching circuitry around it (like if one wants to DC bias it i.e. if you run some current thru the diode, you don't need as much input power to hit it...)

If you know enough to know what a comb generator is, in the AM/FM frequency bands (which are *quite* different in terms of the RF techniques applied within them), just make one (= buy a cheap Schottky diode).

Note that if you build such a thing and there's any power behind it you will be radiating in broadcast bands which is generally frowned upon by The Powers That Be..

Thanks for the advice. I had "Googled" but couldn't get what I really needed, like the path that you have suggested.