View Single Post
  #35   Report Post  
Old October 2nd 06, 05:06 PM posted to rec.radio.shortwave
Seeing-I-dawg Seeing-I-dawg is offline
external usenet poster
 
First recorded activity by RadioBanter: Sep 2006
Posts: 25
Default Wellbrook question


wrote in message
oups.com...

Seeing-I-dawg wrote:
I'll match your dipole against my 70m full-wave horizontal loop for

equal
gain from 70M all they way up to 6M - can you say broadbanded? A dipole

is
not.


Can you rotate your "70M full-wave horizontal loop"?


No need to. It essentially receives equally well in all directions on all
bands, unlike a dipole.

And at 70M, or about 230 feet in "diameter", it is a very different
antenna
then a 1M much touted miracle loop.


No, the circumference is 70 meters = full wave horiz. loop @70M
If you were to transmit into this loop you would see a flat swr from 70M-6M.
No tuner required. Just need to match the ladder line to your tranmitter.
A dipole can't do that without a tuner.

I don't think I was attempting to
compare
3' with 230'. One supposed advantage of the small, fractional
wavelength,
loop is the reported, or should I say reputed, highly directional
charactoristics.
That famous figure "8" pattern.

The dipole to which I am reffering is an amplified, very high IP3 and
IP2 unit with
very good,as in flat gain and very directional, from 100KHz to above
28MHz.


A dipole, any dipole, is cut/tuned for a single band. Any signal outside
that band and its harmonics are attenuated.
Not so with a large loop - equal gain to dipoles at any frequency.

I will
have to connect it to my scanner and see if I can receive any 6M ham
comms,
or more likely around here older 49MHz telephones. I suspect it will
run out of steam somewhere just above 35MHz, but I haven't checked. It
will be later next week before
I can do any tests as my "shack" is in pieces and I am reduced to a
DX398 coupled
to a ~50 random wire out the kitchen window.

Terry


For your perusal:
http://www.cebik.com/wire/hl.html
http://www.cebik.com/fdim/atl1.html
http://www.cebik.com/wire/horloop.html