[Lowfer] Re: [Lowfe Worthwhile going to Shielded loop?r]

Mon, 27 Oct 2003 21:23:30 -0600

Hey Paul,

Where did you get the ferrite stick for that big sucker???

Mike>WE0H

-----Original Message-----
From: [email protected] [mailto:[email protected]]
On Behalf Of paulc
Sent: Monday, October 27, 2003 1:32 PM
To: [email protected]
Subject: [Lowfer] Re: [Lowfe Worthwhile going to Shielded loop?r]

John,

Thanks for lending your experience to the query.
>From your email

 My only experience with shielded receiving loops has been with small,
> multi-turn versions. There were no significant reductions in noise, and
the
> extra capacitance did narrow the tuning range.

Why do  you suppose that there a common notion that says the shielded loop
is quieter?
 Is your loop located far enough from the house that maybe manmade noise is
not a problem?
Perhaps if your only alternative to listen to LF was from an inside the
house location, the shielded antenna have its desired effect?
Seems to me Palomar made a shielded loop for table top use.

To some extent it would seem that size doesn't matter....  for loop antennas
anyway.  Until the antenna "gain" and system noise figure become greater
than the noise floor, seems like the smaller antenna doesn't hurt you.

I have a nearly 3 foot long loopstick I could try in the woods sometime.
Maybe I will do that.  It is tuned for about 160 to 190 Khz

PauLC
W1VLF

----- Original Message -----
From: "John Andrews" <[email protected]>
To: <[email protected]>
Sent: Monday, October 27, 2003 2:35 PM
Subject: Re: [Lowfer] Worthwhile going to Shielded loop?

> Paul,
>
> My only experience with shielded receiving loops has been with small,
> multi-turn versions. There were no significant reductions in noise, and
the
> extra capacitance did narrow the tuning range.
>
> But I haven't played with a larger, single-turn shielded loop. I'd defer
to
> Jay's experience on that one. He and I have produced similar signal
reports
> with our respective antennas. Mine is unshielded, with 14 turns on a 6
foot
> square. The turns are an inch apart. I'd suspect that Jay's antenna
delivers
> more signal (+noise) to the preamp, though. I tried my "Ashlock" loop for
> receiving on 137 kHz last winter, and found that despite the greater
signal
> (+ noise), I wasn't copying anything better than I could with the smaller
> loop. It did offer the possibility of eliminating the preamp, though.
>
> John A.
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