Raytheon P-301 7DX22P Series B Code 1

Belmont-Raytheon model P-301 is a 7-inch electrostatically deflected TV with an unmasked round screen for a "porthole" appearance.  The tuner covers U.S. VHF channels 2 - 13.  The cabinet is covered with faux alligator skin.  Model P-301 is closely related to Raytheon model 7DX22P, but has a different tube lineup and some circuit changes.  Rider TV volume 5 gives "7DX22P" as the chassis number for model P-301.  The chassis itself is marked with both "P-301 Code 1" and (faintly in the case of one example with photos shown here) "7DX22P."

Unlike most 7-inch TVs, the main power supply of this set has neither a power transformer nor a voltage doubler, which allows it to function as a true AC/DC set.  The rectifier uses two selenium rectifiers in a parallel configuration.  An RF high voltage power supply provides 5 kV to the picture tube anode, and also provides elevated B+ for the vertical deflection output stage and picture tube focus grid.  A ballast tube provides appropriate voltage drops for the series filament strings and current limiting for the B+ supply.

The tuner in te P-301, as in some other Raytheon TVs, is a unique permeability-tuned design with a complex mechanical system to raise and lower multiple tuning slugs based on the position of a mechanical adjustment screw set for each channel.  No front-panel fine tuning is provided (a design drawback).

Here you find 442 models, 205 with images and 383 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
All listed radios etc. from Belmont Radio Corp. (B.R.C.); Chicago, Ill.