Rebuilt SB-301 Receiver
The above photo shows the internal layout viewed from above the rear panel.
The square cans on the left are for the RF, mixer and local oscillator tuned circuits and the two PCBs on the rear panel are the AF amplifier and low voltage power supply regulators. The original VFO is in the centre of the front panel and the modified wide band coupler is immediately behind the VFO. The small PCB in the centre is a 150v solid state regulator.
The AM, SSB and CW filters are mounted on the chassis towards the upper right hand corner and the three IF stages are mounted along the right hand side of the chassis finishing near the black mains transformer.
The screened box contains the AM/SSB detectors and three BFO oscillators with the FM detector mounted on top. An additional mains transformer was required to supply the semiconductor circuits.
Front View
Inside View