[time-nuts] Re: WWVB Loopstick Antenna Project

[Lux, Jim]

On 9/11/22 1:06 PM, glenlist via time-nuts wrote:
> Good stuff Paul
>
> What needs to be determined is the required Signal to Noise for the 
> application, since its about using the signal for analytical purposes. 
> That will drive the design and requirements. Higher SNR for indoor 
> antennas will certainly be got with electrostatic (ES) shields -
>
> But the trap  is that you cannot just use a very low efficiency 
> antenna in a high noise environment-Â  with very low efficiency 
> antennas this leaves very small signal values which can easily get 
> drowned out by any common mode noise getting on the cable, which means 
> you have to work VERY hard on common mode rejection / suppression and 
> balance,  and also  garbage getting onto the cable in the shack, if 
> the coax is not choked where it leaves the shack, will take noise to 
> the near field of the antenna !

This is one reason tuned loop/loopsticks are popular - the reasonably 
high Q resonance suppresses out of band signals.