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| The SCR - 578 |
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| 'Gibson Girl' Crystal Radio |
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| 'Gibson Girl' Crystal Radio - Schematic |
Related post: Series-tuned Ferrite Loopstick Crystal Radio
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'Gibson Girl' Crystal Radio
This series-tuned crystal radio was built using parts salvaged from a vintage / battered SCR - 578 lifeboat radio (popularly referred to as 'Gibson Girl').
It consists of a baseplate, antenna tuning coil, antenna tuning capacitor and terminal strip modified to suit.
The only part required to be fished out from the junk box was a Schottky diode SB 860. It was mounted underneath the terminal strip.
The local 612 kHz, 200 kW AM broadcast station comes in real loud with a 60' wire antenna and balanced-armature phones. Headphone current, measured using a 1mA FSD 60 Ω meter, is 750 μA.
Related post: Series-tuned Ferrite Loopstick Crystal Radio
Related post: Series-tuned Ferrite Loopstick Crystal Radio
Loop Antenna Crystal Radio
A loop antenna crystal radio is of interest on account of its selectivity and portability. But, with respect to signal strength, it is no match for a crystal radio using an external vertical wire antenna and earth.
If signal strength could be considerably improved with increased loop size, then its portability would be compromised.
It may be configured as parallel-tuned or series-tuned.
1. Parallel-tuned version
2. Series-tuned version
If signal strength could be considerably improved with increased loop size, then its portability would be compromised.
It may be configured as parallel-tuned or series-tuned.
1. Parallel-tuned version
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| Parallel-tuned Loop Antenna Crystal Radio |
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| Series-tuned Loop Antenna Crystal Radio |
The loop antenna was rigged up using a 4-legged stool as a makeshift frame. The stool was laid on its side on the table, making it convenient to wind the loop on its legs.
Both the versions were tested with the loop oriented end-on towards the local 612 kHz, 200 kW AM broadcast station.
Signal strength was the same with both, though a far cry from another crystal radio using a vertical wire antenna and earth.
Related post: Another Loop Antenna Crystal Radio
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| 4-legged stool as Loop Antenna frame |
Signal strength was the same with both, though a far cry from another crystal radio using a vertical wire antenna and earth.
Related post: Another Loop Antenna Crystal Radio
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