[time-nuts] GPS from a window seat

Bruce Griffiths bruce.griffiths at xtra.co.nz
Fri Oct 2 04:49:53 UTC 2009

SAIDJACK at aol.com wrote:
> Hi Bruce,
> but at first resonance (self resonance) the inductor has the highest  
> impedance that it will ever have (theoretically infinite impedance), which is  
> what you want in a bias-t...
> bye,
> Said
> In a message dated 10/1/2009 19:56:03 Pacific Daylight Time,  
> bruce.griffiths at xtra.co.nz writes:
> You need  to ensure that the coil/inductor doesn't have its first
> resonance below  1575.42MHz for an L1 receiver, otherwise it isn't very
> effective.
> There  are some wideband chokes with first resonances well above 10GHz
> when  mounted  correctly.
> Bruce
Sure, but what about production tolerances?
In any case the actual SRF isn't specified for some parts.
Some of the ferrite filled conical chokes work well.


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