Crosley 3R3, Canadian Version.

[Ed Kraushar]

This Crosley 3R3 was another radio club aquisition. It is Canadian made by the DeForest Radio Corporation in Toronto according to the label and warranty card. Serial number is 3R3-4979.

It was purchased as working, however, when it landed on the bench I found that one of the Crosley interstage audio transformers had been replaced with a Jeffeerson that was open.

The finish on the case is in pretty good condition so it was left alone. The chassis has a chipped corner but that does not affect operation.

I found a proper Crosley audio transformer with an open primary in my storage and rewound it. The open audio had a good secondary of 6.6K ohms resistance. The rewind was 12,800 turns of #41 wire for 5.9K ohms resistance for the secondary and 3200 turns of #40 wire for 1K ohms resistance for the primary. Here is the partial rewind.

The new coil on the Crosley steel.

Schematics for the 3R3 are readily available on-line but they do not match the Canadian made version. There appears to be four differences.

The Canadian version has–
1. Only one rheostat instead of two.
2. No headphone jack.
3. Provision for a “C” battery.
4. An extra grid resistor.

This grid resistor is hidden under the antenna coil as shown in the photo below. It is connected across the secondary of one of the audio interstage transformers and the “C”- battery connects to it. The proper value for it was unknown and the actual value was over 2 meg ohms. I experimented with various resistors and selected a 100K ohm resistor. That value seemed to work well on this chassis. Low values gave a weaker sound while high values gave some distortion.

Performance is fairly good on this radio but tuning is a little touchy. I found overall performance better with a 200A detector than with a 201A.

Ed.

[Author]

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