Scott Radio Laboratories
Though not as prominent a marine radio supplier as RMCA or Lorain Scott Radio Labs. had several different versions of an innovative receiver for marine use. These WW2 vintage Scott marine receivers were designed to have very low local oscillator radiation to thwart the detection of the ship via the enemy's use of radio direction finding gear. Ocean going ships got the priority for these receivers, but some were probably used on Great lakes vessels later on. These units received LW, AM and 3 SW bands, and were 120V AC/DC units; a somewhat unusual arrangement for equipment in a metal cabinet. They were designed this way, not as a cost-cutting measure, but because they were intended for use both with the ships 120VDC supply and on land with the normal 120VAC supply. The versions without the BFO were intended mainly for the reception of entertainment broadcasts - to help maintain morale.
Most of the pictures of the
various versions below were taken by Max Summerville,
The photographer of the others is unknown.
Above is the SLR-F version and right is the SLR-M version. The SLR-M was a commercial version which found uses beyond the marine service.
Above is a SLR-H version with a 1942 date stamp, and right is the RBO-2 version. On the RBO-2 note the absence of the BFO knob below the tuning eye and the addition of the small Dial Lock knob right of the main tuning knob.
the left is the SLR-X - a close relative to the SLR-M version but with
some additional controls at the bottom of the panel. It
appears to be a Navy unit judging from its CRV nomenclature.
This PDF of three Scott Labs advertisements from the 1940s war
years show how Scott's low-radiation receivers kept US shipping quiet and safe from the listening-ears and torpedos of German U Boats.