[time-nuts] Re: WWVB Loopstick Antenna Project

[glenlist]

Hi Paul

FB.   Interference is a bit different now. With power line insulators 
etc these tended to be very fast rise time spikes, and any sort of 
bandwidth reduction as you know just squashes out the pulse. 
Unfortunately with a resonant antenna like is used at LF, bandwidth 
reduction is part of the course ! So very difficult to escape .  Now we 
have different interfering signals with very different statistics and 
character.  The quasi stationary interfering signals are a good 
candidate for blind signal separation techniques.

I also do consulting work for underground magnetic coupled collision 
avoidance systems (60-120 kHz), apart from 160m.....

If users are specifically interesting in building antennas for this you 
can contact Paul or myself directly.

cheers Glen VK1XX, AI6UM

On 12/09/2022 6:40 am, paul swed wrote:
> Well Glen as you say tradeoffs. Always. Thats why the Loops are 162' 
> away from the house with some woods around. The 10' loop is shielded 
> and the 5' not. They are directive. Which helps reduce local noise. 
> Boy does it exist. My noise floor today on the 5' loop is 20 uv. I do 
> hear lots of crud/noise.
>
> I remember when the only thing you needed to worry about was a leaking 
> power line insulator. Power company got tired of fixing them so they 
> invented CFL, LED lights, and switching power supplies. Now they never 
> get calls.......
> The 5' loop is actually tuned for 100 KHz not 60 KHz.
>
> Anyhow go big or go home. Chuckle.
> Regards
> Paul
> WB8TSLom <mailto:time-nuts-leave at lists.febo.com>
>