LF Engineering H-800 antenna
 

Oh, by the way, I didn't mean to suggest that the H-800 is quieter than
the loop. It's not. But it is exceptionally quiet in my experience.

LF Engineering H-800 antenna
 

In article . com,
wrote:

An excellent question. I wish I had an excellent answer. I don't know
why the H-800 is so quiet. I just go with whatever works. Maybe
someone else can help out with greater detail.

wrote:
And why would this vertical be quieter than any other vertical?
Seems to me you can't fight physics.

Even in a quiet spot, a whip plus fet amp will be noisier than a
magnetic loop due to the nature of the noise sources.


wrote:
Actually, I find the H-800 to be astoundingly quiet. It's so
small and so easy to situate in a quiet spot. And once it's
situated, it's as quiet as its location.

Well, it's a small voltage field antenna that you can locate away from
noise sources outside a building is about all it has going for it from
the conceptual standpoint. From a circuit design viewpoint it must have
a well designed low noise amplifier. The reviews indicate it is a good
performance active antenna but it does pick up local noise sources so
the antennas location must be a quite one.

--
Telamon
Ventura, California

LF Engineering H-800 antenna
 

OK, that makes more sense Those active whips are good for quick and
dirty portable use, but a magnetic loop is like magic.

I'd be curious what they use for an amp, since a single fet is par for
the course in that product. Those active whips are real high margin
products.

The Wellbrook is another story. I think they use a high bandwidth
transformer, which is how they float the antenna above ground. North
Hills makes those transformers, but they aren't cheap. When the dust
settled, I figured buying the Wellbrook made more sense than trying to
duplicate one. You can do a differential amp to avoid the transformer,
but that increases the noise.

wrote:
Oh, by the way, I didn't mean to suggest that the H-800 is quieter than
the loop. It's not. But it is exceptionally quiet in my experience.

LF Engineering H-800 antenna
 

wrote in message
oups.com...
And why would this vertical be quieter than any other vertical? Seems
to me you can't fight physics.

Even in a quiet spot, a whip plus fet amp will be noisier than a
magnetic loop due to the nature of the noise sources.

Better read this before we start discussing that a loop can distinguish
noise sources.
http://www.w8ji.com/magnetic_receiving_loops.htm

I see two reasons why a loop might be quieter:
1. If there is a single noise source, the loop's null may be used to reduce
the source
2. Active whips must have a good ground at the antenna. Without it, the
coaxial shield becomes part of the antenna- both picking up noise in the
house and conducting noise from the house back to the whip.


Dale W4OP

LF Engineering H-800 antenna
 

LF Engineering H-800 antenna
 

Dale Parfitt wrote:

Better read this before we start discussing that a loop can distinguish
noise sources.

True enough. I had to go to fairly extreme lengths to find a permanent
location for the Wellbrook because it was picking up noise. In the end,
I needed to locate it in exactly the same spot I'm using the H-800 in
now. The Wellbrook is definitely quieter than the H-800, but it's not
uncommon for me to make out signals on the H-800 that I cannot make out
on the Wellbrook--no doubt for many of the reasons Telemon described
(polarization, frequency, time of day, etc.). Don't get me wrong: The
Wellbrook is the better antenna overall, but the H-800 doesn't get
nearly enough credit in my view. It's significantly cheaper than the
Wellbrook and is manufactured right here in the good ole' U. S. of A. I
think it's an excellent value.

LF Engineering H-800 antenna
 

Mark S. Holden wrote:

I use an active whip for camping trips and vacations - largely because
they're easy to transport and set up. The one I'm using now is a 3
meter whip that folds like a tent pole with an impedance matching
transformer, and a milspec Avantek low noise high gain amp.

What model Avantek amp' are you using?

LF Engineering H-800 antenna
 

225ft from any noise source. Great .Let's see. I could buy the 3 homes
across the street, 3 behind me, and the homes on either side, then tear
them all down. So that's 8 homes at about $650k each, or $5.2 million.

No, I think it's better to spend a bit more and get the Wellbrook.


Mark S. Holden wrote:
wrote:
The LF looks like an amplified whip. I seriously doubt it would be in
the Wellbrook league. Those amplified whip are really noisy, especially
at lower frequencies.

Maybe in the Mojave you can get away with an amplified whip.



The trick with a whip is putting it in a low noise location.

My random wire at home is at least 225 feet away from any source of rfi.
An H800 or H900 would work fine back there.

I use an active whip for camping trips and vacations - largely because
they're easy to transport and set up. The one I'm using now is a 3
meter whip that folds like a tent pole with an impedance matching
transformer, and a milspec Avantek low noise high gain amp.

Obviously it's easy to find a quiet spot for an antenna when you're in
the woods.

Fortunately, it's also easy for me to set up an antenna in a low noise
location at the three places I tend to go for vacations and weekend
getaways - and they're good places for swl - perhaps because they're all
on or very near water.

LF Engineering H-800 antenna
 

Or maybe you have the space for, say, a 100 ft wire? The Wellbrook is a
great antenna, so long as you find a quiet spot for it. In general,
though, I would trade it for 100 ft of wire in a quiet location.

LF Engineering H-800 antenna
 

My yard measures 170 feet,front to back and 60 feet side to side.Or is
it 160 feet front to back and 70 feet side to side? I forget,I did
measure it off a bunch of years ago.Of course I could run an overhead
wire diagonaly from Southeast to Northwest or Southwest to Northeast.I
dont think those two single women next door to me would mind if I ran an
overhead wire from my yard across their yard and I could double the
lenght of overhead wire.Those people who live on the other side,next
door to me probally wouldn't mind either.I could triple the lenght of
overhead wire and I dont think those people who live next door to those
two single women next door to me,two houses down the street from me
would mind all that much either.The possibilities are endless around
here.
cuhulin