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I've got a Flights of Fancy AM crystal receiver that has been in the attic for years. I want to put it together but can't find the instruction booklet. Is anyone familiar with this receiver? Does anyone know how it should be wired?

I just add a schematic of how it was wired about 10 years ago. There is no capacitor anywhere. The last wrap of the coil wire is about 3" long and just hangs in the air.

Using a 15ft long antenna and sweeping across the 5" length of coil I get only two stations. Any ideas what would improve it?

schematic of flights of fancy

I would appreciate any thoughts on my latest schematic below. I've also added a resistor.

Thanks,enter image description here henrylr

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  • \$\begingroup\$ Google is probably your best friend. \$\endgroup\$
    – Andy aka
    Dec 10, 2016 at 21:12
  • \$\begingroup\$ Crystal radios are quite simple. We can probably explain what should be connected to what from a photograph. \$\endgroup\$ Dec 10, 2016 at 21:55

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Am going out on a limb here (cannot find a schematic), and you should too, to attach one end of the antenna wire. In the photos for "Flights of Fancy", I see a tapped inductor, an earpiece audio transducer. The diode is small and not easily visible. I do not see a capacitor. Nevertheless, an inductor, diode and headphone are minimum components (in addition to antenna and ground). Some possible schematics:

schematic

simulate this circuit – Schematic created using CircuitLab

The antenna is a long wire whose far end is not connected, but is ideally up high. Ever seen AM antenna site with multiple towers extending 70 M up? That's an ideal length (but less will still give results). The diode is attached to the coil somewhere along its length to give best volume. Diode direction does not matter. The speaker must be a coil-of-wire type that reacts with a permanent magnet. Modern headphones are of the correct type, but have too-low impedance to give much volume. Old high-impedance headphones are ideal.
Note that a ground connection is very necessary. A connection to metallic plumbing distribution is fine but any plastic parts along the path to outside ground will reduce effectiveness. Metal fencing usually has long runs that make it attractive for ground. On my wall outlets, a single screw attaches the plastic cover plate - that's a decent ground as well, because all my boxes hidden in the wall are grounded metal. However, a curious child might try plugging into the outlet resulting in disaster.

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  • \$\begingroup\$ Thanks glen_geek, that is a nice schematic. Any idea where a capacitor would be connected in the schematic? \$\endgroup\$
    – henrylr
    Jan 13, 2017 at 21:24
  • \$\begingroup\$ @henrylr resonating variable capacitor might go from antenna-to-ground in parallel with the whole coil. I wonder if capacitance is hidden inside the cylinder on which the coil is wound? Adding the capacitor aids in selecting one station from many. \$\endgroup\$
    – glen_geek
    Jan 13, 2017 at 22:09
  • \$\begingroup\$ I've made a schematic of how the flights of fancy is set up, but need to find out how to include it. It is a JPG file. The unattached coil wire on one end makes me think it is not the best setup. \$\endgroup\$
    – henrylr
    Jan 14, 2017 at 17:45
  • \$\begingroup\$ file:///C:/Users/Henry/Pictures/flights%20os%20fany/Flights%20of%20fancy%20radio%20schematic.jpg \$\endgroup\$
    – henrylr
    Jan 14, 2017 at 20:40
  • \$\begingroup\$ I'm just trying to figure out how to get my JPG schematic to show up on this site. \$\endgroup\$
    – henrylr
    Jan 14, 2017 at 20:41
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The Wikipedia entry of "Crystal radio" shows several possible schematics. A good earth ground, not through a plastic water pipe, is important. Note that the galena crystal is picky about where the "cat's whisker" is set on it, you have to adjust it's placement by getting the highest audio volume.

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