What Antenna for Short Wave

I just bought a portable AM-FM-SW radio. It picks up pretty well on
all bands, but I live in a metal house and know I am losing signal
because of it. In fact I took the radio outdoors and got much better
reception. The radio just has a single telescoping antenna that comes
up to about 30 inches. I want to add an outdoor antenna for the
shortwave. I was told that any piece of wire strung from the house to
a pole would help. I can only clip it onto the telescoping antenna
since there is no antenna connector on the radio, so I'd just use an
alligator clip. My question is what the ideal length of the wire
should be, or don't it matter? OR maybe it should be as long as I can
make it? Also, does height matter? Or does the location matter, such
as going east, north, or .....

Please advise me.

Thanks

LM

 

[Arfa Daily]

<letterman@invalid.com> wrote in message
news:f5v6o4hbs14o02c8m40ggfq9s144i5l6p0@4ax.com...

I just bought a portable AM-FM-SW radio. It picks up pretty well on
all bands, but I live in a metal house and know I am losing signal
because of it. In fact I took the radio outdoors and got much better
reception. The radio just has a single telescoping antenna that comes
up to about 30 inches. I want to add an outdoor antenna for the
shortwave. I was told that any piece of wire strung from the house to
a pole would help. I can only clip it onto the telescoping antenna
since there is no antenna connector on the radio, so I'd just use an
alligator clip. My question is what the ideal length of the wire
should be, or don't it matter? OR maybe it should be as long as I can
make it? Also, does height matter? Or does the location matter, such
as going east, north, or .....

Please advise me.

Thanks

LM

For general 'short wave' reception, any random length of wire is
appropriate. General rules of thumb are make it as long as is practical in
the space available, as high as you can get the whole thing, or any part of
it, keep any part of it as far away from any high voltage cables as
possible, use good insulators at any physical suspension points. It needn't
face in any particular direction, but a good compromise is to 'bend it at
some convenyient point along its length if you can, so you might be able to
run it say from a point on the eaves of your roof to the top of the fence at
the bottom of the garden, and then turn it 90 deg to run along the top of
the fence across the bottom of the garden. Anything you can come up with
that fits the space, really ...

You might not need (or in fact want) to make a direct physical connection to
the telescopic antenna. Experiment with just wrapping a few turns of the
(still insulated) end of the wire around the telescopic. You can also try
grounding the end of the wire, and then wrapping a few turns around the
telescopic. If you do use an external antenna with the radio, I would not
recommend leaving it connected - or even just wrapped around - the
telescopic, on a permanent basis. When there are thunderstorms about, very
significant static voltages can build up on external antennas, and if there
is an actual lightning ground-strike within a couple of miles of your house,
large 'real' pulse voltages can be induced in long-wire antennas.

Arfa

 

[Bill Janssen]

letterman@invalid.com wrote:

I just bought a portable AM-FM-SW radio. It picks up pretty well on
all bands, but I live in a metal house and know I am losing signal
because of it. In fact I took the radio outdoors and got much better
reception. The radio just has a single telescoping antenna that comes
up to about 30 inches. I want to add an outdoor antenna for the
shortwave. I was told that any piece of wire strung from the house to
a pole would help. I can only clip it onto the telescoping antenna
since there is no antenna connector on the radio, so I'd just use an
alligator clip. My question is what the ideal length of the wire
should be, or don't it matter? OR maybe it should be as long as I can
make it? Also, does height matter? Or does the location matter, such
as going east, north, or .....

Please advise me.

Thanks

LM


Local noise sources will limit the weak signal reception. So try to keep

the antenna far away from any power lines,
electric fences etc. Then after that, use a high, long piece of wire

Bill K7NOM

 

On Fri, 30 Jan 2009 16:25:46 -0600, letterman@invalid.com wrote:

I just bought a portable AM-FM-SW radio. It picks up pretty well on
all bands, but I live in a metal house and know I am losing signal
because of it. In fact I took the radio outdoors and got much better
reception. The radio just has a single telescoping antenna that comes
up to about 30 inches. I want to add an outdoor antenna for the
shortwave. I was told that any piece of wire strung from the house to
a pole would help. I can only clip it onto the telescoping antenna
since there is no antenna connector on the radio, so I'd just use an
alligator clip. My question is what the ideal length of the wire
should be, or don't it matter? OR maybe it should be as long as I can
make it? Also, does height matter? Or does the location matter, such
as going east, north, or .....

Please advise me.

Thanks

LM

A Short Wave antenna that is longer, higher and more clear of any
obstructions such as the side of your house will work best.

It has been my experience that you do not need to actually go to these
extreme lengths to get more than enough signal pickup. For a simple
effective not to ugly omni-directional outdoor Short Wave antenna all
you have to do is make a helical vertical antenna and mount it on the
roof. Just take any plastic or non conductive form like a 2" - 4" PVC
pipe and wind wire helically, similar to the threads on a bolt. As
little as a three foot plastic pipe with only 15 foot of wire will
work great.

 

[William Sommerwerck]

<letterman@invalid.com> wrote in message
news:f5v6o4hbs14o02c8m40ggfq9s144i5l6p0@4ax.com...

I just bought a portable AM-FM-SW radio. It picks up pretty
well on all bands, but I live in a metal house and know I am
losing signal because of it.

If the house is metal (a Quonset hut?), why not just attach the radio to the
house?

To paraphrase Stan Freberg -- "Your whole house becomes a giant antenna.
It's settled."

 

On Fri, 30 Jan 2009 20:46:26 -0500, tnom@mucks.net wrote:

On Fri, 30 Jan 2009 16:25:46 -0600, letterman@invalid.com wrote:

I just bought a portable AM-FM-SW radio. It picks up pretty well on
all bands, but I live in a metal house and know I am losing signal
because of it. In fact I took the radio outdoors and got much better
reception. The radio just has a single telescoping antenna that comes
up to about 30 inches. I want to add an outdoor antenna for the
shortwave. I was told that any piece of wire strung from the house to
a pole would help. I can only clip it onto the telescoping antenna
since there is no antenna connector on the radio, so I'd just use an
alligator clip. My question is what the ideal length of the wire
should be, or don't it matter? OR maybe it should be as long as I can
make it? Also, does height matter? Or does the location matter, such
as going east, north, or .....

Please advise me.

Thanks

LM

A Short Wave antenna that is longer, higher and more clear of any
obstructions such as the side of your house will work best.

It has been my experience that you do not need to actually go to these
extreme lengths to get more than enough signal pickup. For a simple
effective not to ugly omni-directional outdoor Short Wave antenna all
you have to do is make a helical vertical antenna and mount it on the
roof. Just take any plastic or non conductive form like a 2" - 4" PVC
pipe and wind wire helically, similar to the threads on a bolt. As
little as a three foot plastic pipe with only 15 foot of wire will
work great.

I like this idea. As Bill said, avoid electric fences. My whole farm
has them, and they are all the way around the house, with the closest
being 15 feet in the rear, and the furthest being over 100ft in front.
I'd have to run this wire out the rear because there is my drive in
front and with combines and large farm equipment going down there, it
would need to be really high. In the rear I'd be going over the elec
fences. This pvc idea is probably the best because I can mount it to
the mast on my tv antenna with spacers. I can run the wire inside in
the same place as the tv coax. plus it would be well above my electric
fences. Thanks to all the who replied.

LM

 

[Arfa Daily]

<letterman@invalid.com> wrote in message
news:bpd7o4htgpa9f70iv4o1tq0cgnn4jhj2jm@4ax.com...

On Fri, 30 Jan 2009 20:46:26 -0500, tnom@mucks.net wrote:

On Fri, 30 Jan 2009 16:25:46 -0600, letterman@invalid.com wrote:

I just bought a portable AM-FM-SW radio. It picks up pretty well on
all bands, but I live in a metal house and know I am losing signal
because of it. In fact I took the radio outdoors and got much better
reception. The radio just has a single telescoping antenna that comes
up to about 30 inches. I want to add an outdoor antenna for the
shortwave. I was told that any piece of wire strung from the house to
a pole would help. I can only clip it onto the telescoping antenna
since there is no antenna connector on the radio, so I'd just use an
alligator clip. My question is what the ideal length of the wire
should be, or don't it matter? OR maybe it should be as long as I can
make it? Also, does height matter? Or does the location matter, such
as going east, north, or .....

Please advise me.

Thanks

LM

A Short Wave antenna that is longer, higher and more clear of any
obstructions such as the side of your house will work best.

It has been my experience that you do not need to actually go to these
extreme lengths to get more than enough signal pickup. For a simple
effective not to ugly omni-directional outdoor Short Wave antenna all
you have to do is make a helical vertical antenna and mount it on the
roof. Just take any plastic or non conductive form like a 2" - 4" PVC
pipe and wind wire helically, similar to the threads on a bolt. As
little as a three foot plastic pipe with only 15 foot of wire will
work great.

I like this idea. As Bill said, avoid electric fences. My whole farm
has them, and they are all the way around the house, with the closest
being 15 feet in the rear, and the furthest being over 100ft in front.
I'd have to run this wire out the rear because there is my drive in
front and with combines and large farm equipment going down there, it
would need to be really high. In the rear I'd be going over the elec
fences. This pvc idea is probably the best because I can mount it to
the mast on my tv antenna with spacers. I can run the wire inside in
the same place as the tv coax. plus it would be well above my electric
fences. Thanks to all the who replied.

LM

It's worth a try for sure, but depending on the frequencies of interest, you
might find that the performance is sometimes not as good as you might
expect, due to the fact that this type of antenna will have a fundamentally
vertical response pattern. This is great for say CB transmissions which are
normally vertically polarised from both base stations and mobiles, but not
so great for ham transmissions in similar bands, which are more likely to be
(at least initially) horizontally polarised as horizontal wire antennas or
horizontal beams are often what are used for transmitting on. A 'sloper' is
often a good compromise, as it has a roughly equal response to both
vertically and horizontally polarized signals. The best suggestion really,
is to just arm yourself with a roll of wire and a few long bamboo poles,
pick a nice warm Saturday when you've got nothing else to do, and have a
little experiment. If you had a sloper passing over the top of your rear
electric fence, provided that it was ten feet or so above the 'active'
strand, you might be surprised at how little interference it actually
caused.

Arfa

 

[Meat Plow]

On Fri, 30 Jan 2009 16:25:46 -0600, letterman@invalid.comwrote:

I just bought a portable AM-FM-SW radio. It picks up pretty well on
all bands, but I live in a metal house and know I am losing signal
because of it. In fact I took the radio outdoors and got much better
reception. The radio just has a single telescoping antenna that comes
up to about 30 inches. I want to add an outdoor antenna for the
shortwave. I was told that any piece of wire strung from the house to
a pole would help. I can only clip it onto the telescoping antenna
since there is no antenna connector on the radio, so I'd just use an
alligator clip. My question is what the ideal length of the wire
should be, or don't it matter? OR maybe it should be as long as I can
make it? Also, does height matter? Or does the location matter, such
as going east, north, or .....

Please advise me.

Thanks

LM

An end fed, horizontally oriented random length of wire should do just
fine. The longer the better and the height isn't too important.

 

[Engineer]

On Jan 30, 7:23 pm, "Arfa Daily" <arfa.da...@ntlworld.com> wrote:

letter...@invalid.com> wrote in message

news:f5v6o4hbs14o02c8m40ggfq9s144i5l6p0@4ax.com...

(snip)

You might not need (or in fact want) to make a direct physical connection to
the telescopic antenna. Experiment with just wrapping a few turns of the
(still insulated) end of the wire around the telescopic. You can also try
grounding the end of the wire, and then wrapping a few turns around the
telescopic.

(snip)

No, don't ground anything. Any coil around the metal telescopic
antenna is effectively shorted by the metal "core" (a single shorted
turn - read transformer theory.) If you ground the end you short out
all the antenna signal. If you leave it ungrounded you have decent
capacitive coupling that works.
But if you take a few turns around a true antenna coil (to make a
primary coil) you will couple some signal into the radio - but this is
generally too much trouble. Better, connect the antenna via a 100 pF
capacitor to the telescopic antenna.
Cheers,
Roger

 

[Arfa Daily]

"Engineer" <junk2007@rogers.com> wrote in message
news:07a737ae-cbb0-45af-ad72-d558fe929217@g1g2000pra.googlegroups.com...
On Jan 30, 7:23 pm, "Arfa Daily" <arfa.da...@ntlworld.com> wrote:

letter...@invalid.com> wrote in message

news:f5v6o4hbs14o02c8m40ggfq9s144i5l6p0@4ax.com...

(snip)

You might not need (or in fact want) to make a direct physical connection
to
the telescopic antenna. Experiment with just wrapping a few turns of the
(still insulated) end of the wire around the telescopic. You can also try
grounding the end of the wire, and then wrapping a few turns around the
telescopic.

(snip)

No, don't ground anything. Any coil around the metal telescopic
antenna is effectively shorted by the metal "core" (a single shorted
turn - read transformer theory.) If you ground the end you short out
all the antenna signal. If you leave it ungrounded you have decent
capacitive coupling that works.
But if you take a few turns around a true antenna coil (to make a
primary coil) you will couple some signal into the radio - but this is
generally too much trouble. Better, connect the antenna via a 100 pF
capacitor to the telescopic antenna.
Cheers,
Roger

There are many references on the 'net to 'inductively' coupling an external
long wire antenna to a telescopic, by either wrapping turns directly around
the telescopic, and grounding the 'free' end, or by wrapping the turns
around a tube, also with the free end grounded, and then sliding the tube
over the telescopic, the latter method claiming to allow a certain amount of
'adjustment' to the degree of coupling, to prevent strong signals
overloading the front end, and giving rise to all manner of intermod
products.

Arfa

 

On Tue, 3 Feb 2009 01:50:42 -0000, "Arfa Daily"
<arfa.daily@ntlworld.com> wrote:

"Engineer" <junk2007@rogers.com> wrote in message
news:07a737ae-cbb0-45af-ad72-d558fe929217@g1g2000pra.googlegroups.com...
On Jan 30, 7:23 pm, "Arfa Daily" <arfa.da...@ntlworld.com> wrote:
letter...@invalid.com> wrote in message

news:f5v6o4hbs14o02c8m40ggfq9s144i5l6p0@4ax.com...

(snip)

You might not need (or in fact want) to make a direct physical connection
to
the telescopic antenna. Experiment with just wrapping a few turns of the
(still insulated) end of the wire around the telescopic. You can also try
grounding the end of the wire, and then wrapping a few turns around the
telescopic.

(snip)

No, don't ground anything. Any coil around the metal telescopic
antenna is effectively shorted by the metal "core" (a single shorted
turn - read transformer theory.) If you ground the end you short out
all the antenna signal. If you leave it ungrounded you have decent
capacitive coupling that works.
But if you take a few turns around a true antenna coil (to make a
primary coil) you will couple some signal into the radio - but this is
generally too much trouble. Better, connect the antenna via a 100 pF
capacitor to the telescopic antenna.
Cheers,
Roger

There are many references on the 'net to 'inductively' coupling an external
long wire antenna to a telescopic, by either wrapping turns directly around
the telescopic, and grounding the 'free' end, or by wrapping the turns
around a tube, also with the free end grounded, and then sliding the tube
over the telescopic, the latter method claiming to allow a certain amount of
'adjustment' to the degree of coupling, to prevent strong signals
overloading the front end, and giving rise to all manner of intermod
products.

Arfa

OK, now we have two conflicting sources of information. Aside from
trying both of them and seeing which works better I am not sure
whether to ground it or not ?????
I would have thought this would be an established fact !

 

[Dave]

<letterman@invalid.com> wrote in message
news:insfo490h8tn7172vuvoqg5ru74rk8bbu1@4ax.com...

On Tue, 3 Feb 2009 01:50:42 -0000, "Arfa Daily"
arfa.daily@ntlworld.com> wrote:


"Engineer" <junk2007@rogers.com> wrote in message
news:07a737ae-cbb0-45af-ad72-d558fe929217@g1g2000pra.googlegroups.com...
On Jan 30, 7:23 pm, "Arfa Daily" <arfa.da...@ntlworld.com> wrote:
letter...@invalid.com> wrote in message

news:f5v6o4hbs14o02c8m40ggfq9s144i5l6p0@4ax.com...

(snip)

You might not need (or in fact want) to make a direct physical
connection
to
the telescopic antenna. Experiment with just wrapping a few turns of the
(still insulated) end of the wire around the telescopic. You can also
try
grounding the end of the wire, and then wrapping a few turns around the
telescopic.

(snip)

No, don't ground anything. Any coil around the metal telescopic
antenna is effectively shorted by the metal "core" (a single shorted
turn - read transformer theory.) If you ground the end you short out
all the antenna signal. If you leave it ungrounded you have decent
capacitive coupling that works.
But if you take a few turns around a true antenna coil (to make a
primary coil) you will couple some signal into the radio - but this is
generally too much trouble. Better, connect the antenna via a 100 pF
capacitor to the telescopic antenna.
Cheers,
Roger

There are many references on the 'net to 'inductively' coupling an
external
long wire antenna to a telescopic, by either wrapping turns directly
around
the telescopic, and grounding the 'free' end, or by wrapping the turns
around a tube, also with the free end grounded, and then sliding the tube
over the telescopic, the latter method claiming to allow a certain amount
of
'adjustment' to the degree of coupling, to prevent strong signals
overloading the front end, and giving rise to all manner of intermod
products.

Arfa


OK, now we have two conflicting sources of information. Aside from
trying both of them and seeing which works better I am not sure
whether to ground it or not ?????
I would have thought this would be an established fact !

I personally have a (roughly) 110 foot random wire antenna hiding under the
edges of the ridgevent on my house, and it is only grounded in the sense
that the shield of the coax between it and my radio is attached to a couple
of 10 foot copper-plated ground rods driven into the ground. The "signal"
line (wire antenna and center conductor of the coax) are not attached to
ground anywhere, as this would indeed kill any signal intended for the input
of the radio. And the coax comes in my wndow and terminates in a "male"
plug, to which I attach an alligator clip that goes to a foot or so of
(insulated) wire that I coil around my (closed) whip antenna. And this
works great. Note that I only use the coax to shield the signal line
against EMI from the A/C that all of this has to go past to get to my
window. The shield to that coax is grounded where line comes off of the
roof, and again where it comes in my window. At the random-wire end, the
shield is unconnected, and the center conductor of the coax is soldered to
the 110 feet of wire. Also, if you directy connect the wire antenna to your
whip, I believe you may eventually have trouble from static discharge
building up from wind blowing across the wire. Note that I said "I
believe", as I do not actually *know* this to be a fact. But that is why I
put a static discharge circuit into the RF amplifier that I built to enhance
weak signals.

My $.02. Hope that perhaps it helps...

Shortwave Dave

 

[GregS]

In article <ptmdnen5qMK36BXUnZ2dnUVZ_qfinZ2d@posted.internetamerica>, "Dave" <db5151@hotmail.com> wrote:

letterman@invalid.com> wrote in message
news:insfo490h8tn7172vuvoqg5ru74rk8bbu1@4ax.com...
On Tue, 3 Feb 2009 01:50:42 -0000, "Arfa Daily"
arfa.daily@ntlworld.com> wrote:


"Engineer" <junk2007@rogers.com> wrote in message
news:07a737ae-cbb0-45af-ad72-d558fe929217@g1g2000pra.googlegroups.com...
On Jan 30, 7:23 pm, "Arfa Daily" <arfa.da...@ntlworld.com> wrote:
letter...@invalid.com> wrote in message

news:f5v6o4hbs14o02c8m40ggfq9s144i5l6p0@4ax.com...

(snip)

You might not need (or in fact want) to make a direct physical
connection
to
the telescopic antenna. Experiment with just wrapping a few turns of the
(still insulated) end of the wire around the telescopic. You can also
try
grounding the end of the wire, and then wrapping a few turns around the
telescopic.

(snip)

No, don't ground anything. Any coil around the metal telescopic
antenna is effectively shorted by the metal "core" (a single shorted
turn - read transformer theory.) If you ground the end you short out
all the antenna signal. If you leave it ungrounded you have decent
capacitive coupling that works.
But if you take a few turns around a true antenna coil (to make a
primary coil) you will couple some signal into the radio - but this is
generally too much trouble. Better, connect the antenna via a 100 pF
capacitor to the telescopic antenna.
Cheers,
Roger

There are many references on the 'net to 'inductively' coupling an
external
long wire antenna to a telescopic, by either wrapping turns directly
around
the telescopic, and grounding the 'free' end, or by wrapping the turns
around a tube, also with the free end grounded, and then sliding the tube
over the telescopic, the latter method claiming to allow a certain amount
of
'adjustment' to the degree of coupling, to prevent strong signals
overloading the front end, and giving rise to all manner of intermod
products.

Arfa


OK, now we have two conflicting sources of information. Aside from
trying both of them and seeing which works better I am not sure
whether to ground it or not ?????
I would have thought this would be an established fact !


I personally have a (roughly) 110 foot random wire antenna hiding under the
edges of the ridgevent on my house, and it is only grounded in the sense
that the shield of the coax between it and my radio is attached to a couple
of 10 foot copper-plated ground rods driven into the ground. The "signal"
line (wire antenna and center conductor of the coax) are not attached to
ground anywhere, as this would indeed kill any signal intended for the input
of the radio. And the coax comes in my wndow and terminates in a "male"
plug, to which I attach an alligator clip that goes to a foot or so of
(insulated) wire that I coil around my (closed) whip antenna. And this
works great. Note that I only use the coax to shield the signal line
against EMI from the A/C that all of this has to go past to get to my
window. The shield to that coax is grounded where line comes off of the
roof, and again where it comes in my window. At the random-wire end, the
shield is unconnected, and the center conductor of the coax is soldered to
the 110 feet of wire. Also, if you directy connect the wire antenna to your
whip, I believe you may eventually have trouble from static discharge
building up from wind blowing across the wire. Note that I said "I
believe", as I do not actually *know* this to be a fact. But that is why I
put a static discharge circuit into the RF amplifier that I built to enhance
weak signals.

My $.02. Hope that perhaps it helps...

Shortwave Dave

In any case a static discharge device would be very NICE to have.
We used to use Blitz Bugs on antennas. I don't know what the rating
was. There are probably other low capcitance devices that can be used to drain
a charge, even a high value resistor will drain a charge to ground without
affecting the antenna. Having an outside "spark plug" to ground would make me happier.

greg

 

[Michael A. Terrell]

letterman@invalid.com wrote:

OK, now we have two conflicting sources of information. Aside from
trying both of them and seeing which works better I am not sure
whether to ground it or not ?????
I would have thought this would be an established fact !

news:rec.radio.amateur.antenna would be the right newsgroup for your
questions.


--
http://improve-usenet.org/index.html

aioe.org, Goggle Groups, and Web TV users must request to be white
listed, or I will not see your messages.

If you have broadband, your ISP may have a NNTP news server included in
your account: http://www.usenettools.net/ISP.htm


There are two kinds of people on this earth:
The crazy, and the insane.
The first sign of insanity is denying that you're crazy.

 

[Van Chocstraw]

letterman@invalid.com wrote:

I just bought a portable AM-FM-SW radio. It picks up pretty well on
all bands, but I live in a metal house and know I am losing signal
because of it. In fact I took the radio outdoors and got much better
reception. The radio just has a single telescoping antenna that comes
up to about 30 inches. I want to add an outdoor antenna for the
shortwave. I was told that any piece of wire strung from the house to
a pole would help. I can only clip it onto the telescoping antenna
since there is no antenna connector on the radio, so I'd just use an
alligator clip. My question is what the ideal length of the wire
should be, or don't it matter? OR maybe it should be as long as I can
make it? Also, does height matter? Or does the location matter, such
as going east, north, or .....

Please advise me.

Thanks

LM

I thought short wave radio was dead. Internet radio has far more to offer.



--
<<//--------------------\\>>
Van Chocstraw
>>\\--------------------//<<

 

[bz]

"Arfa Daily" <arfa.daily@ntlworld.com> wrote in
news:FqNhl.1$5z5.0@newsfe30.ams2:

"Engineer" <junk2007@rogers.com> wrote in message
news:07a737ae-cbb0-45af-ad72-d558fe929217@g1g2000pra.googlegroups.com...
On Jan 30, 7:23 pm, "Arfa Daily" <arfa.da...@ntlworld.com> wrote:
letter...@invalid.com> wrote in message

news:f5v6o4hbs14o02c8m40ggfq9s144i5l6p0@4ax.com...

(snip)

You might not need (or in fact want) to make a direct physical
connection to
the telescopic antenna. Experiment with just wrapping a few turns of
the (still insulated) end of the wire around the telescopic. You can
also try grounding the end of the wire, and then wrapping a few turns
around the telescopic.

(snip)

- No, don't ground anything. Any coil around the metal telescopic
- antenna is effectively shorted by the metal "core" (a single shorted
- turn - read transformer theory.) If you ground the end you short out
- all the antenna signal. If you leave it ungrounded you have decent
- capacitive coupling that works.
- But if you take a few turns around a true antenna coil (to make a
- primary coil) you will couple some signal into the radio - but this is
- generally too much trouble. Better, connect the antenna via a 100 pF
- capacitor to the telescopic antenna.
- Cheers,
- Roger

There are many references on the 'net to 'inductively' coupling an
external long wire antenna to a telescopic, by either wrapping turns
directly around the telescopic, and grounding the 'free' end, or by
wrapping the turns around a tube, also with the free end grounded, and
then sliding the tube over the telescopic, the latter method claiming to
allow a certain amount of 'adjustment' to the degree of coupling, to
prevent strong signals overloading the front end, and giving rise to all
manner of intermod products.

Arfa

IF you were to ground one end of the coil AND ground the top end of the
whip antenna, you would turn the whip into a single turn of wire and have
inductive coupling.

Otherwise, regardless of what it says 'on the net' most of the coupling is
capacitive, from the 'hot end' of the coil to the whip.

If you tight wrap a few turns of insulated wire around the whip antenna,
you probably have half a dozen or so pF of capacitance, which should be
sufficient for many purposes.




--
bz 73 de N5BZ k

please pardon my infinite ignorance, the set-of-things-I-do-not-know is an
infinite set.

bz+ser@ch100-5.chem.lsu.edu remove ch100-5 to avoid spam trap

 

[GregS]

In article <V5udnRT6OM_05hXUnZ2dnUVZ_uednZ2d@earthlink.com>, "Michael A. Terrell" <mike.terrell@earthlink.net> wrote:

letterman@invalid.com wrote:

OK, now we have two conflicting sources of information. Aside from
trying both of them and seeing which works better I am not sure
whether to ground it or not ?????
I would have thought this would be an established fact !


news:rec.radio.amateur.antenna would be the right newsgroup for your
questions.

I don't agree. Its a Ham newsgroup.

How about rec.radio.shortwave


greg

 

[GregS]

In article <yNudnbOci5Xa4RXUnZ2dnUVZ_rXinZ2d@giganews.com>, Van Chocstraw <boobooililililil@roadrunner.com> wrote:

letterman@invalid.com wrote:
I just bought a portable AM-FM-SW radio. It picks up pretty well on
all bands, but I live in a metal house and know I am losing signal
because of it. In fact I took the radio outdoors and got much better
reception. The radio just has a single telescoping antenna that comes
up to about 30 inches. I want to add an outdoor antenna for the
shortwave. I was told that any piece of wire strung from the house to
a pole would help. I can only clip it onto the telescoping antenna
since there is no antenna connector on the radio, so I'd just use an
alligator clip. My question is what the ideal length of the wire
should be, or don't it matter? OR maybe it should be as long as I can
make it? Also, does height matter? Or does the location matter, such
as going east, north, or .....

Please advise me.

Thanks

LM


I thought short wave radio was dead. Internet radio has far more to offer.

There is no mystery in hooking up your internet line. Well probably.

Installing antennas, experimenting with equipment, doing what people
have done or never done, is nothing like the Internet.
Turning the dial and watching the S meter is nothing like the Internet.
Decoding signals, listening to CW, is nothing like the Internet.
The Internet has far more to offer, but the real thrill is getting there.


greg

 

[bz]

Van Chocstraw <boobooililililil@roadrunner.com> wrote in
news:yNudnbOci5Xa4RXUnZ2dnUVZ_rXinZ2d@giganews.com:
.....

I thought short wave radio was dead.

No. Listen on the shortwave bands and you will still hear broadcasts from
all over the world.

Internet radio has far more to offer.

It doesn't offer the challenges that shortwaves offer.

It doesn't offer the 'backup' capability that two-way communications (such
as ham radio) over shortwaves offer in times of widespread emergencies.

It doesn't offer the 'fun' of building your own transmitter and talking to
someone half way around the world, using less power than it takes to light
up an LED.


--
bz 73 de N5BZ k

please pardon my infinite ignorance, the set-of-things-I-do-not-know is an
infinite set.

bz+ser@ch100-5.chem.lsu.edu remove ch100-5 to avoid spam trap

 

[Dave]

"GregS" <zekfrivo@zekfrivolous.com> wrote in message
news:gma7vr$m3d$2@usenet01.srv.cis.pitt.edu...

In article <yNudnbOci5Xa4RXUnZ2dnUVZ_rXinZ2d@giganews.com>, Van Chocstraw
boobooililililil@roadrunner.com> wrote:
letterman@invalid.com wrote:
I just bought a portable AM-FM-SW radio. It picks up pretty well on
all bands, but I live in a metal house and know I am losing signal
because of it. In fact I took the radio outdoors and got much better
reception. The radio just has a single telescoping antenna that comes
up to about 30 inches. I want to add an outdoor antenna for the
shortwave. I was told that any piece of wire strung from the house to
a pole would help. I can only clip it onto the telescoping antenna
since there is no antenna connector on the radio, so I'd just use an
alligator clip. My question is what the ideal length of the wire
should be, or don't it matter? OR maybe it should be as long as I can
make it? Also, does height matter? Or does the location matter, such
as going east, north, or .....

Please advise me.

Thanks

LM


I thought short wave radio was dead. Internet radio has far more to offer.

There is no mystery in hooking up your internet line. Well probably.

Installing antennas, experimenting with equipment, doing what people
have done or never done, is nothing like the Internet.
Turning the dial and watching the S meter is nothing like the Internet.
Decoding signals, listening to CW, is nothing like the Internet.
The Internet has far more to offer, but the real thrill is getting there.


greg

Definetly agree. The Internet has its place, but so does shortwave. And
shortwave is just so much more fun... There is nothing like building
something that takes you someplace else without having to leave home. As
one person on rec.radio.shortwave put it, when you finally succeed in
pulling that signal out from underneath all the rest, and seperate it from
the all the noise, to hear someone giving you his inside take on whatever
situation while a rooster crows in the background, you know you have good
DX. I will never forget tuning into 9335 Khz at 0800 Central Standard Time
to hear the broadcast from the capital of what we know as North Korea to
hear the broadcast marking the 50th anniversary of that dictatorship, even
if I knew it *was* pure propaganda. The fact is that on the far edge of
night I picked up a fairly week signal from the other side of the world that
I knew was not rebroadcast anywhere along the way. Now, I didn't know it
then, but this signal is easy to get on the West coast, and was only as
difficult as it was for me because I was operating off a whip antenna from
inside of a house with steel siding. The addition of an external antenna
made all the difference in the world.



Dave

Like the other guy said, experience is what you get when you don't get what
you want.