[Lowfer] Re: [Lowfer]a big aperiodic loop?

[Steve Dove]

Hi Larry,

It is 200 feet of RG6 in a diamond shape, the top being at about 70 feet up.  
The shield has a 1 inch break at the top.  At ground level the two inners feed a 
differential virtual-earth amplifier (i.e. it is current-sensed, the amplifier having an 
input impedance dynamically forced to near-zero).  This feeds a couple of 
hundred feet of RG6 back to the shack, after a local grounding of the shield and 
a mondo common-mode choke.  

At the shack, it is transformer-coupled into a distribution amplifier which feeds the  
DCF-39 monitor and whatever else I want to hang off it.

It is aperiodic in the sense of 'untuned' to distiguish it from most loops, which are 
tuned.  Although the signal level from it is lower than that of a tuned loop (no 
'magnification factor' of the resonant 'Q') the fact that it can't become untuned is 
a big plus when consistency of signal levels is a requirement (DCF-39 
monitoring).

Although nearly as sensitive as anything else here (not quite as good as a tuned 
loop, which still lies on its side, still forlorn and broken) it is prone to the 
'squirglies',  some of which are picked up by the antenna itself but most from 
common-mode sensitivity  (pick-up on the feedline etc.) which has taken much 
effort to quell, not entirely successfully.

        Cheers,

                Steve


12/17/2003 12:54:10 PM, LarryP WB3ANQ <wb3anq@comcast.net> wrote:

>Steve Dove wrote:
>
>>Hi John,
>>
>>Yes, it is directional  -  it's presently on a big aperiodic loop, NE/SW, meaning 
>>Mitch should be in a null and it should be favouring VO1NA!
>>
>>  
>>
> Steve,
>
>What is a big aperiodic loop??
>
>73
>
>Larry