The radios are not pictures of radios. Each chassis is its schematic, with real part values, and the game works out every voltage and every sound from it.
I
The tubes follow their data sheets
Each tube's curves are fitted through its data sheet's operating point. The voltages you read with the meter are solved from the whole circuit many times a mains cycle, not looked up, and a healthy set reads its service chart.
II
Faults are parts gone wrong
A dried filter capacitor is a smaller capacitor with more resistance, and the hum comes out of the ripple it lets through. A leaky coupling capacitor drags the output grid positive. Nothing is scripted, so two faults in one set combine as they would.
III
Warm-up is heat
The filaments glow up over seconds as they heat, cold tungsten a fraction of its hot resistance, and the sound fades in with the cathodes. A battery portable's filaments are on almost at once, as they were.
IV
A restorer's order of work
The dim-bulb tester first. The meter against the service chart. The signal tracer stage by stage until the signal stops. The iron, the parts drawer, the signal generator for the IF cans, the tube tester, and a knock on the chassis for the tube that rings.
V
The cabinet has its own craft
Wash first, and use the gentlest thing that works. Compound brings dull Bakelite back and takes the paint off an ivory set. A wet cloth lifts the numerals printed on the back of a dial glass. Harm shows the moment it starts, and it doesn't come back out.
VI
The station keeps its day
Switch on a set from the shelf and Radio La Ronda plays by your clock: the morning news, the pasillo hour at noon, the radionovela at seven, the match on Sunday afternoons. After dark, distant stations drift in on the sky wave.
