[time-nuts] WWVB BPSK Receiver Project? (fwd)

Brooke Clarke brooke at pacific.net
Sat Mar 17 21:01:48 UTC 2012


Hi:

The material permeability gets reduced to effective permeability depending on the rod length / diameter radio (you would 
like it to be >= 100) to realize the material permeability).
For example:  http://www.magneticsgroup.com/pdf/erods.pdf

More on ferrite loop sticks at:
http://www.prc68.com/I/Loop.shtml

Have Fun,

Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/Brooke4Congress.html


lists at lazygranch.com wrote:
> Wouldn't the difference be directly proportional to the relative permeability? If so, the difference would be more like 125, not 10, depending on core material.
>
> -----Original Message-----
> From: ehydra<ehydra at arcor.de>
> Sender: time-nuts-bounces at febo.com
> Date: Sat, 17 Mar 2012 21:22:17
> To: Marek Peca<marek at duch.cz>; Discussion of precise time and frequency measurement<time-nuts at febo.com>
> Reply-To: ehydra at arcor.de, Discussion of precise time and frequency measurement
> 	<time-nuts at febo.com>
> Subject: Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)
>
> Marek Peca schrieb:
>> This was almost the only reason for ferrite rod -- simplicity and
>> attenuation of TVs, some LCDs, 50Hz etc.
> If you make the antenna about 10x bigger you can omit the whole ferrite.
> The only benefit of a ferrite loaded coil is the size of it!
> In ancient time radios had flat air coils like spider webs. In fact they
> are named after spiders in german.
> This air coil can be resonated too!
>
> I can imagine a resonated vertical antenna. Never seen that but all it
> requires is a low impedance pre-amp stage and a loading coil of very high Q.
>
> - Henry
>



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