Page 84 - Build Your Own Transistor Radios a Hobbyists Guide to High-Performance and Low-Powered Radio Circuits

while load inductors L1 and L2 are increased to 2.2 mH to 4.7 mH and with load

resistors R2 and R5 increased from 6,200

to 20 k

. Try one stage at a time with these suggested modifications.
Author's Earllier TRF Designs

As stated previously, the designs from Figures 5-1 and 5-2 actually came after
designing three different TRF radios with a 3-volt supply. At that time, all three
designs used only resistor loads at the collectors of the transistor voltage-gain

amplifiers. It wasn't until the reflex radios (with transfonmer and/or inductive loads)
were designed for Chapter 6 that I realized that the answer to lower-voltage radios
was right in front of me-use inductors for the load instead of just resistors.
So sometimes a "final" design does not always have a straight path, but the
journey is still fun and exciting in terms of learning new things ..

See the three designs in Figures 5-3, 5-4, and 5-5; they are for reference only. But
the reader can decide if he or she would like to build any of them.

RF Ant. Filter Multi-Stage Amplifier Det

VC&T1 01 to 06 Q7
Loop Antenna
+ 3

R13 C6
47K :UHR~:orn
2

C5
330K
~~4126 ~
0.0033 uf
R7
20K
Low Side
Tap

FIGURE 5-3 Block diagram and schematic of a previous TRF radio design.