WWV receiver

Huh? Yes, he is well into RF and construction techniques will be different. But while there are advantages to air-coil cores, their use in recievers went out with hollow state detectors. Even in transmitters they tend to be only used in the KW neighborhood anymore. I can't imagine that even in the wilds of BC people are winding air coils and building on heavy steel chassis.

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He wants to listen, and at least at 10 MHz there's something to listen TO. The 60Khz signal is pretty strange.

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No, its not. It was never intended to be listened to. It has a 1 BPS data rate encoded time signal that has always been used to carry time code.

I think that Coilcraft, API-Delavan, Pulse, etc. would be surprised to hear them. Although I'd grant you that you don't typically find many air coils in mass-market consumer electronics anymore, they're still used all over the place in industrial and military design... where I work we buy tens of thousands of the things every year for radio receivers!

Plenty of articles appearing in QEX and on-line also use air-core coils, since it's a pretty fast and you can, of course, get whatever value you want with no "minimum purchase" quantities.

---Joel Kolstad

Tobin wrote "... easier to decode". So I guess he is after decoding and not so much after listening.

Regards, Joerg

Hello Joel,

To imitate an old Volkswagen ad: Air doesn't saturate. Well, I guess it does at some point but that's way past where ferrites and iron powders do. Today many inductors in receivers are designed around iron powder cores but when it comes to heavy-duty stuff air cores are the ticket. Same for really high-Q tuning circuits.

Regards, Joerg