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Philco AA5 Radio

The AA5 radio is one of the most popular radios ever made. It stands for All-American 5 Radio

It was made by a single company, but by many manufacturers. There were a few variations, but they were all very similar. They were typically built like this
AM broadcast band receiver (535-1700 KHz)
115 VAC or VDC
Typically, 2 knobs, one for on/off/volume and one for tuning

No power transformer
Metal chassis encased in a plastic bakelite or wood cabinet
Internal antenna

AA5 Radio Schematic
Admiral AA5 Radio, with antenna attached. See the 5 tubes?

The mains connected directly to the tubes and ran them all in series. They typically had this tube lineup:
35Z5 – Power rectifier
50L6 – Final audio amplifier
12SQ7 – Detector, audio amplifier
12SK7 – Intermediate frequency amplifier
12SA7 – Converter

Since the tubes were connected in series, if one of the heaters was damaged, none of the other tubes would light up.

Because of the metal chassis and lack of a transformer, these were very dangerous if the case was damaged or the tuning knobs were missing.

Because of their age and abundance, there are many sitting in attics and basements across the US. They are common at estate sales, flea markets, ham fests, and yard sales. They typically don’t work because of the wax and electrolytic capacitors inside them.

Before you touch or open one of these radios, PLEASE PLEASE PLEASE read the safety materials on them. Careless handling could result in serious injury or death from electric shock.

Once you have reviewed the safety materials, you should look at the next article on what to replace/repair first.

First Step: How to Recap a Radio

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