They plug together. Ten card edge sockets at top of picture show SRS input boards. Power supply weighs 18 pounds. Brand New General Electric 6146B's Great building block for QRP Linear Amplifier. Milliwatts drive to full output.
Verniers control air variable capacitors.
N connectors, voltage input terminal block. Just add power supply and go. Uses highest quality components. Made in Germany. PD100 rated at 25 amps.