[time-nuts] simple phase finder

[David Van Horn]

Be careful, shielding can lower the Q impressively due to parasitic capacitance.
Winding more than about a third of the length results in flux lines not coupling to the outboard turns.
Ferrite antennas are fascinating.

https://en.tdk-electronics.tdk.com/download/2176996/8d0ef9c30ea64c62edc15b3a2888f6d9/ferrites-impeder-cores-pp.pdf
Ferrite impeder cores may work better than solid cores, if the material works at frequency.
I've seen a magnetic version of the "Skin effect" in ferrites, and increasing the perimeter seems to work better than a solid rod.


-----Original Message-----
From: time-nuts <time-nuts-bounces at lists.febo.com> On Behalf Of jimlux
Sent: Wednesday, December 5, 2018 3:18 PM
To: Discussion of precise time and frequency measurement <time-nuts at lists.febo.com>
Subject: Re: [time-nuts] simple phase finder

On 12/5/18 7:30 AM, Poul-Henning Kamp wrote:
> --------
> In message <d88d97a3-6715-760b-2219-2dedd18789a3 at earthlink.net>, jimlux writes:
> 
>> If anyone has a suggestion for an off the shelf active antenna that's 
>> orderable and receivable by Friday, I'd love to hear it.  There's 3 
>> or 4 of them I've seen (Clifford labs, DX Engineering has one, I'm 
>> sure MFJ has one)
> 
> There is one experiment I have thought about, but not tried:  Wind a 
> big loop, run it directly into a sound card with microphone input.
> 

That's true.. many turns would give you more voltage.

Hmm, I've got a 3 foot long, 6" diameter tesla coil secondary with about
800 turns on it.

Aluminum foil over it for an electrostatic shield would be easy.


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