This 715B has the prefix CRP that denotes that the maker is Raytheon. The Type designation is 715B.
The 715B is a tetrode pulse modulator intended to be driven by a rectangular pulse. The peak current demands require four independent cathodes and the warm-up time should be three minutes if full current is to be drawn. The peak pulse power is 225 kW and the anode has a 60 Watt dissipation.
The 715B is a direct equivalent to the STC P535-1E and was intended for use in aircraft radar systems.
The construction is substantial with ceramic insulators used due to the high voltages involved. The anode plates are stitched together around the wire supports.
The uncoated tops of the four cathodes. The two grid wires are just visible. The copper grid supports both have heat dissipating fins on their tops.
Here the white coating on the cathodes is visible as is the flattened cylinder anode, made of thin nickel sheet, and the gold plated grid wires.
A closer view into the top of the anode. The cathode tubes have a reduced section at the top that fits into the ceramic top plate.
The wide glass tube envelope is 64 mm in diameter, and excluding the B4A base pins is 134 mm tall.