RadioBanter - View Single Post

March 7th 04, 12:03 AM

(Dxluver) wrote in message ...
The main reason I like to keep it on the group is if I lay a clam,
someone will usually correct me.

huh, OK.

Yea...

As an example, the other day I said a pancake loop's nulls
were at right angles compared to a solenoid loop. The reason I said
this, was I saw it mentioned on a web page somewhere. But after
thinking about it more, I'm not so sure that is correct. Seems to me,
they should act the same as a solenoid loop as far as null direction,
being they are both "small loops". But I'm not sure...All my current
loops are solenoid. Any comments from any pancake loop owners? Are the
nulls broadside to the loop, as in a solenoid loop? Or opposite?
I do know a ferrite bar antenna is opposite from a solenoid loop. BTW,
I just built a new bigger loop yesterday. It's a diamond loop appx 43
inches per side.
It's 5 ft across at the spreaders. Built it from PVC and is a simple
cross frame. I have it in the room with me, and it's rotatable on a
stand like my 16 inch loop. It's working real good so far. It does
give a lot more voltage than the small loop. About 2 s units worth on
average. Will be good for weak signals in quiet cdx. Good for LW too,
being it's pretty big. Started out with 7 turns, but ended up with 5.
I couldn't tune 160m at first. I'm using two variable caps, one appx
850 pf?, and one that is maybe 50 pf or less full mesh, and two sets
of fixed capacitance to tune from 250 cycles to about 2.5 mhz. On the
high end, I'm using very small capacitance values. In fact, I had to
take a 3 150 pf?? "guessing" piece variable, and only use one section
for those upper freqs. The balance came out as good as my other one,
and about equal or better nulls. Using a one turn coupling loop inside
the tank coil. The nulls seem even and the same either side. Thats
what you really want to see. If they slew off from actual direction,
or are unequal , you know you have a balance problem.
MK