I have never done one that low in frequency before. I suspect there are some tricks to getting the limiter diode to respond the same at microwaves as at 10 MHz. At microwave frequencies, the sine wave is changing so fast that the electrons have trouble going from one side of the I region to the other in that half-cycle. At 10 MHz, they have all the time in the world. That would cause a change in the limiting threshold power, is suspect.
You might try a limiter that has a diode that is biased by a schottky diode...that way the biasing is controlled by the schottky instead of relying on the I region thickness. Just an idea.
The design is simple. Series DC blocking cap at RF input port, shunt PIN diode (with a thin I region), inductor/capacitor bias line, quarterwave transmission line, series blocking cap, schottky rectifying diode feeding the rectified current back thru the bias line to the PIN diode, series blocking cap at RF output port.