William Sommerwerck wrote:

As that time draws close, you'll have to turn the radio up a little
more to get the same volume, but you probably won't notice. Then, the
sound will become a little distorted, and you might eventually notice
that. Not too much later, what you describe will happen. (The FM
section takes more power than the AM and will stop working sooner.)

I've never seen a radio in which the tuner sections are separately
powered. Compared to the output stages, they draw little current.

Since the topic of this thread is the GE Superadio, you should look at the
schematics of the radio to provide some validity to your statement.
According to the schematics, both the Superadio I and Superadio III remove
power to the tuner circuits not being used.

While the tune sections may draw little current relative to the audio
circuitry when performing at full output, at lower output, the extra
current can have a significant impact on battery life.



And very few radios -- the GE P970A being an exception -- have separate AM
and FM tuners. We never established if this was the case with the
Superradio.

Your apparent definition of tuner refers to the variable capacitor. Again,
your statement can be verified by looking at the schematics. The Superadio
I uses a single 6 section variable capacitor. The Superadio III uses
varactors for tuning. They are driven from a single source.

However, if your definition of tuner includes all the circuitry from the
antenna to detected audio, the Superadio I and III do not have separate
tuners as they both have common IF circuits.