[Lowfer] New Loop NG

[Peter Barick]

Ok, John, I can try the 1:4 balun, turns on separate sides.

>>> w1tag@charter.net 04/16/02 12:01PM >>>
Peter,

> *PB: The balun is 1:1, 2 X25 t. on a 75 core, from the LWCA site.

Do me a favor, and do it as a primary/secondary transformer, two
separate
windings, opposite sides of the core, 25 turns on each side. If you
want to
try the 1:4 experiment, do 12 turns on the loop side, and 24 turns on
the
receiver side.

>The
> preamp is Lyle's High-Gain single ended with provision for loop or
low-Z
> inputs. I had previously used the amp indoors w/ a parallel tuned
box
> loop and was fimilar w/ how it tuned and the general performance of
a
> loop like that.

As I recall, the Lo-Z side wasn't all that low. I'll dig up the
schematic
for the preamp I'm using.
*PB: The "LOZ" input is a pie having a 4.7mH choke, w/ a 220pF to gnd.
off of the ant side and a var. of 400pF tuniing the other side going to
the FET.
 
> *PB: The rx is Drake R-8 w/ 50 and 500 ohm inputs. I used the 50 ohm
w/
> coax.

OK - We'll assume that Drake had it right, unless anyone else has
evidence
to the contrary.

> *PB: Right. When adding the link I shorted the balun winding.

The side toward the loop, or the side toward the receiver?
*PB, Ans: The loop side only.

John A.


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