On Sat, 28 Jan 2006 10:51:12 -0600, wrote:

Whip antennas are notorious for getting bent up or breaking or getting
mashed/kinked or coming loose.E1 radios (in my opinion) just look as
though they should have built in ferrite core antennas for AM recption.I
have many radios that have AM band plus some other bands too and every
one of them that have AM band,they all have a built in ferrite core
antenna.Sometimes,it might not be conveniet to pull up those E1 antennas
to use the AM band,for instance sitting in a cubbyhole or a small
space.It just seems to me that there is something missing from E1
radios.
cuhulin

What a cool visual. Coohoo drinking beer on the sofa with his hound
dog and his WebTV wireless keyboard getting all tangled up with a
chrome plated, bent all to ****, telescoping whip antenna.
Priceless...

In article ,
"Lenny" wrote:

So, how exactly do you use the nulls?
Does the ferrite rod move around inside the radio with a control?
Lenny

"Telamon" wrote in message
...
In article ,
"Lenny" wrote:

Thanks Telamon.
Lenny

"Telamon" wrote in message
.
..
In article ,
"Lenny" wrote:

OK, I'll admit it. I don't know what people are talking about when
they say the E1 doesn't have an AM antenna.

People have stated that the E1 does not have an internal "ferrite rod"
antenna inside.

Doesn't it have a whip antenna.

Yes.

What more could you want?

An internal "ferrite rod" antenna inside.

What the heck is a "ferrite rod antenna" anyway?

It's a closed loop type antenna utilizing a high permeance core (the
ferrite) in order to take up less space.

And what does it do differently than the whip?

1. More convenient to use as you don't have to have the long whip
sticking out when you carry it around.

2. The whip is omnidirectional and the loop ferrite rod antenna has two
nulls in the pattern that you could use to null out a competing station
of local noise source, which could improve your reception.

3. The ferrite loop is less susceptible to pick up local noise sources
being sensitive to the magnetic field component whereas the whip is
sensitive to the electric field.

No problem Lenny.

#2 Should have been "competing station or local noise source."

I need a Usenet editor.

Using the photos provided in the thread by weatherall you can see that
the coiled ferrite rod goes across the top of the case. The nulls are
symmetrical about the rod and exist at the ends of the rod. The "Null"
is where the rod antenna will be the least sensitive to a broadcast
station. The null off both rod ends is a very small just a few degrees
around the rod antenna ends and the maximum reception would be when the
rod antenna is broadside to the station. Due to the length and width of
the rod antenna this almost always means that the radio front or back
should be facing the station.

http://www.radiointel.com/review-tecsunpl200.htm

How to use this to your benefit? Lets say that either another station
or a local noise source is interfering with your reception. You would
point the side of the radio toward the interference reducing the level
of interference. This will only work if the interference is on a
different heading then the station you are trying to hear.

The best use of the null will involve acknowledging that we live in an
(at least) 3D world so whereas the null will be found is by rotating
the radio on a compass heading it can be made "deeper" by aditionally
tilting the radio in the vertical axis.

Here is an analogy as to what you are trying to accomplish by nulling
an interference source. Radio waves are a different frequency of
electromagnetic waves same as light waves. It you had a white rod on a
black background some distance from you holding a flash light next to
your head then the rod would hardest to see when the end of it was
pointed at you representing a small dot. If your eyes were the
interference then the rod would have the least exposure to you when the
end was pointed right at you rotating the rod in the X (compass) and
vertical altitude directions so you can only see the very end of it.

--
Telamon
Ventura, California

weatherall wrote:

Wrote:
Yeah well, if Eton hadn't pushed this receiver into the marketplace at
such manic, breakneck speed, then maybe they'd have had time to
include
a ferrite antenna and make the display quieter. Better to take your
time and do it right than launch a product prematurely--even if it
means missing a deadline or two.

Sarcasm?

http://www.radiointel.com/review-etone1.htm

"Originally unveiled in prototype form at the Consumer Electronics Show
in Chicago in 1996 as the Grundig Satellit 900, the E1 has followed a
long road from those first mockup models to commercial realization."

Yeah, the long and winding road to recall...

dxAce
Michigan
USA

David wrote:
On Sat, 28 Jan 2006 10:51:12 -0600, wrote:

Whip antennas are notorious for getting bent up or breaking or getting
mashed/kinked or coming loose.E1 radios (in my opinion) just look as
though they should have built in ferrite core antennas for AM recption.I
have many radios that have AM band plus some other bands too and every
one of them that have AM band,they all have a built in ferrite core
antenna.Sometimes,it might not be conveniet to pull up those E1 antennas
to use the AM band,for instance sitting in a cubbyhole or a small
space.It just seems to me that there is something missing from E1
radios.
cuhulin

What a cool visual. Coohoo drinking beer on the sofa with his hound
dog and his WebTV wireless keyboard getting all tangled up with a
chrome plated, bent all to ****, telescoping whip antenna.
Priceless...


It was even funnier the first three times he did it. That's why he now
only buys pre-broken radios from the Goodwill Store.



mike

On Sat, 28 Jan 2006 07:25:58 -0500, "Lenny"
wrote:

Great pix, thanks Weatherall.
Does the Ferrite Rod only aid in AM broadcast reception, or does it also aid
SW reception?
Lenny

In most AM/FM radios, the ferrite bar antenna is for AM reception
only. A separate whip antenna for FM is reasonably close to a quarter
wavelength on the FM frequencies; a 1/4 wave whip antenna on the AM
band, 530 to 1700 Khz, would be hundreds of feet long, hence the
shortened AM antenna using the ferrite rod. On little radios, the rod
is a couple of inches long, on others such as the C.Crane CCRadio or
the GE SuperRadio the rod is bigger, about 8 inches long, hence their
supposed "DXing" capabilities for AM.

On shortwave radios, I'm not sure which frequencies the ferrite bar
would be used for, certainly the American AM broadcast band, not sure
about others.

One disadvantage to the whip antenna, it is vertical, and vertical
polarization picks up more manmade interference. Horizontal antennas
such as the ferrite bar are a little more immune.

Bob
k5qwg


"weatherall" wrote in message
...

Lenny Wrote:
OK, I'll admit it.
I don't know what people are talking about when they say the E1 doesn't
have
an AM antenna.
Doesn't it have a whip antenna.
What more could you want?
What the heck is a "ferrite rod antenna" anyway?


Hi Lenny:
Here are pictures of the insides of a Tecsun PL-200 radio. It's hosted
on radiointel.com, a fun & useful site. In some of the pictures you
will see tightly coiled copper wire around a bar (that's the ferrite).
It's at the top of the radio, and would be on the left side if you're
looking at the front.

http://www.radiointel.com/review-tecsunpl200.htm


--
weatherall

Some ferrite rod antennas are round,some ferrite antennas are sort of
flat bar shaped.I have a lot of radios that have flat shaped bar ferrite
antennas.
cuhulin

On Mon, 30 Jan 2006 13:16:08 -0600, wrote:

Some ferrite rod antennas are round,some ferrite antennas are sort of
flat bar shaped.I have a lot of radios that have flat shaped bar ferrite
antennas.
cuhulin

Yeah, and I have an old Adcom tuner with kind of a loop shaped ferrite
antenna that you can wiggle back and forth on the back of the preamp.
Surprised none of the DX-am-ers have picked up on that.

bob
k5qwg

"Bob Miller" wrote in message
...
On Sat, 28 Jan 2006 07:25:58 -0500, "Lenny"
wrote:

Great pix, thanks Weatherall.
Does the Ferrite Rod only aid in AM broadcast reception, or does it also
aid
SW reception?
Lenny

In most AM/FM radios, the ferrite bar antenna is for AM reception
only. A separate whip antenna for FM is reasonably close to a quarter
wavelength on the FM frequencies; a 1/4 wave whip antenna on the AM
band, 530 to 1700 Khz, would be hundreds of feet long, hence the
shortened AM antenna using the ferrite rod.

But a SW whip antenna is usually much less than 1/4 wave, as well. The
whips can be resonated with additional components, but they usually aren't.
It isn't necessary.


On little radios, the rod
is a couple of inches long, on others such as the C.Crane CCRadio or
the GE SuperRadio the rod is bigger, about 8 inches long, hence their
supposed "DXing" capabilities for AM.

On shortwave radios, I'm not sure which frequencies the ferrite bar
would be used for, certainly the American AM broadcast band, not sure
about others.

Radios with a longwave band would also use the ferrite rod antenna for that
band. I've seen radios, such as the Realistic DX-100 which use a ferrite
antenna for each of the SW bands. In the case of the DX-100, the antenna is
used mostly as the inductance of the input tuned circuit. Nearly all the
signal power on SW comes in through a whip or external antenna. Moving the
radio has practically no effect on the signal or interference.



One disadvantage to the whip antenna, it is vertical, and vertical
polarization picks up more manmade interference. Horizontal antennas
such as the ferrite bar are a little more immune.

Bob
k5qwg


On most radios, the whip doesn't have to be vertical. Sometimes
interference can be minimized by moving the whip, although it often doesn't
make much difference.

The horizontal ferrite bar radio antenna is magnetically horizontal, but
electrically vertical, just like the whip antenna. However, the ferrite
antenna is much less prone to capacitive noise pickup from whatever
electronic stuff is running.

Frank Dresser