These were supposed to replace the 7530 final, not sure how well that worked out or if you can still find them now.
ERF9530 RF Power Mosfet Transistor, 100 Watts PEP, 30 MHz, TO3PN Case
The ERF9530 feature new silicon wafer designs with greatly improved quality and durability. Palomar’s new wafer technology creates a new level of ruggedness for these RF power MOSFETs that are now able to withstand all adverse conditions - high heat, high VSWR, high voltages and current levels.
The ERF9530 is a drop-in replacement and upgrade for the ERF7530 transistor and features a new TO-3PN insulated package for the mounting screw. The ERF9530 is conservatively rated at 100 watts PEP.
FEATURES
• High Power and Economical:
Pout > 25W (100W PEP)
Gp > 10dB @ 12.5V, f=30MHz
MFR: Palomar