Two-tube radio
made a few years ago from plans in the
January 1929 issue of Radio News magazine.
(Plans designated by Radio News as Blueprint 71)

The article was titled "The 'Bloopless' One-Dial, Two-Tube Receiver".
The radio is a regenerative design with an untuned RF amplifier stage. The main purpose of the untuned RF amplifier stage was isolation, keeping oscillation from the regenerative circuit from reaching the antenna and causing interference to other receivers.

Fig. 5
The schematic diagram of the "Bloopless" set shows the circuit in a form easy to
read; many constructors prefer to build from a schematic. The resistor R1 saves
making another coil.


R1=100K ohms.
R2 and R3 are 1/4 ampere filament ballast resistors.
R4 is 2 megohm grid-leak resistor.
R5 is 2K ohm.
C1 is .00035 mf.
C2 is .00025 mf.
C3 is .0005 mf.


Fig. 7
"Details for making coil L to be used with a .00035 mf. condenser."


Return to Museum display and poster index