= = = "HankG" no_one@invalid wrote in message
= = = ...
My primary antenna is a 33 ft folded dipole made from 300 ohm twin lead and
is mounted in my roof. It is coupled by a 300 to 75 ohm tv transformer to
75 ohm coax. The antenna is described in message 2471 of the Yahoo Rx-320
group and works fairly well.

Recently, I acquired 3 rolls (40 ft each) of indoor 300 ohm coax, a closeout
at Radio Shack. On checking my house diagram (drawing), I determined that I
could run another antenna which could run about 100 feet if I include my
garage. This is measured from left rear roof, through a wall, diagonally to
front right garage (plus a 20 ft wrap on each end).

I'd welcome any suggestions from the group on an antenna configuration such
as dipole, folded dipole, twinlead converted to long wire (doubled back on
itself), etc. This would be for SW reception, but MW would be a plus.
Thanks.

HankG


HankG,

If you wish to work with what you have then an In-the-Attic Horizontal
{Flat} 'double' Loop Antenna using the 300 Ohm Twin Lead would most
likely give you a good SWL "Receive Only" Antenna with broad banded
reception with low noise characteristics.

HOW-TO-DO-IT: In-the-Attic Horizontal {Flat} 'double' Loop
Antenna using the 300 Ohm Twin Lead as the Antenna Wire Elements.

Take your three rolls of Forty Foot (40') 300 Ohm Twin Lead and
connect
them End-to-End and Wire-to-Wire to form a piece of 120 Foot Twin
Lead.
(Any length of 300 Ohm Twin Lead will do; the longer the better.)

* Antenna Wire Element.
Inspect and Evaluate your Attic (or Roof) to determine how you plan to
to 'place' (run/route) the Antenna Wire Element of the Horizontal
{Flat}
Loop Antenna.
- Ideally this is at a Height of 5'-7' above the Attic Floor.
- The Loop need not be Square or a Rectangle and can be any shape
that
"Fits" the 'conture' of your Attic.
- You can use Bent-Nails, Eye Bolds or Cup-Hooks as Anchor-Mounting
Points for the Antenna Wire Element. (Tape them with Black Electrical
Tape if you wish.)
- You have Four Wire coming out of the two ends of the 120 Foot
Antenna
Wire Element (two loops). Connect two of the Wire-Ends so that you
now
have a Double Loop that is 240 Feet Long. The two free Wire-Ends are
to
connect to your Balun (Matching Transformer).
NOTE: The Loop can be a 30' Square; a 10'/15'/20'/25' by
50'/45'/40'/35'
Rectangle or any shape that adds up to 120' overall.
FWIW: The Loop Size can be Down-Sized or Up-Sized to "Fit" your
'available'
Attic Space.

* Balun (Matching Transformer) and Coax Cable.
- Buy and use a TV type 300 Ohm to 75 Ohm Balun (Matching
Transformer).
(Look for one that states on the package that it is good down to 5
MHz.
Along with 75 Ohm Coax Cable. (I would recommend DDS type RG-6 Coax
Cable
with the attached Ground Wire.)
- OR - Buy or Build a SWL 4:1 (up to 10:1) Balun (Matching
Transformer)
to used with 50 Ohm Coax Cable. (I would recommend RG-8 'Mini' Coax
Cable.)
- Connect the two free Wire-Ends are to connect to your Balun
(Matching
Transformer).

* Grounding.
Insure that you have a good earthen ground using a Eight Foot (8')
Ground
Rod and Heavy Duty Ground Wire/Strap for you Shack's Radio Equipment
and
Antenna.

RESULTS: You now have a Horizontal {Flat} Loop Antenna that is 120
Feet
long with a 'double' Loop Wire Antenna Element that is 240 Feet long.
That uses a Balun to connect and match it to the Coax Cable
Feed-in-Line;
plus a Ground for your Radio Equipment and Antenna.
+ Lower Noise Horizontal {Flat} Loop Antenna.
+ Lower Noise Balun and Coax Cable Feed-in-Line.
+ Ground Rod and Wire for Lower Noise.

Connect the Ground and Antenna to your Radio/Receiver and Enjoy
Broadcast
and Shortwave Listening ) ) ) ) ) ) ) ) ) ) )
)


iane ~ RHF
..
Some Say: On A Clear Day You Can See Forever.
http://groups.yahoo.com/group/Shortw...na/message/502
I BELIEVE: On A Clear Night . . .
You Can Hear Forever and Beyond, The BEYOND !
..
..

In article , dxAce
wrote:

HankG wrote:

"Telamon" wrote in message

...
In article ,
"HankG" no_one@invalid wrote:

"Telamon" wrote in message


..
.
In article ,
"HankG" no_one@invalid wrote:

My primary antenna is a 33 ft folded dipole made from 300 ohm twin
lead and is mounted in my roof. It is coupled by a 300 to 75 ohm
tv
transformer to 75 ohm coax. The antenna is described in message
2471
of the Yahoo Rx-320 group and works fairly well.

Recently, I acquired 3 rolls (40 ft each) of indoor 300 ohm coax, a
closeout at Radio Shack. On checking my house diagram (drawing), I
determined that I could run another antenna which could run about
100
feet if I include my garage. This is measured from left rear roof,
through a wall, diagonally to front right garage (plus a 20 ft wrap
on each end).

I'd welcome any suggestions from the group on an antenna
configuration such as dipole, folded dipole, twinlead converted to
long wire (doubled back on itself), etc. This would be for SW
reception, but MW would be a plus. Thanks.

You could take two of those 40 foot pieces and make a 80 foot folded
dipole antenna.

Yes. The resonant frequency of an (un)folded dipole of 80 ft would be
about
5.85 Mhz. My current antenna (resonant at 14.18 Mhz) uses a twinlead
stub
which supposedly confers a broader bandwidth. I have used it to
monitor
160
meters and works fairly well in the single digits. Is there a formula
for
calculating stub length to give this 80 footer greater bandwidth?

According to a Joe Carr antenna book I have this:
In meters
A - 141.8 / F MHz - Over all length or distance between outer shorts
B - 122 / F MHz - distance between inner shorts

In addition you could leave the outer shorts open then it would be:
A - 142 / F MHz - Over all length or distance between outer ends
B - 122 / F MHz - distance between inner shorts

Example for 9.75 MHz is
A = 14.56 meters
B = 12.51 meters

Some of the Radio Shack 300 / 75 ohm transformers are not much good
below 10MHz.

Interestingly, I acquired the transformers (2 on a card) at the local
dollar
store. Works fine.

Well, it depends on which one you got your hands on. On some the S21
falls off below 10MHz and you were talking about a lower frequency
antenna so just watch out for that.

What is meant by inner and outer 'shorts'?

Well, I guess you've never seen some of those kids running around the 'hood'.

Some of them wear their shorts on the inside, some of them wear them on the
outside.

Very funny!

--
Telamon
Ventura, California

In article ,
"HankG" no_one@invalid wrote:

"Telamon" wrote in
message

gy.com.. .
In article ,
"HankG" no_one@invalid wrote:

"Telamon" wrote in
message


gy.com..
.
In article ,
"HankG" no_one@invalid wrote:

My primary antenna is a 33 ft folded dipole made from 300 ohm
twin lead and is mounted in my roof. It is coupled by a 300
to 75 ohm tv transformer to 75 ohm coax. The antenna is
described in message 2471 of the Yahoo Rx-320 group and works
fairly well.

Recently, I acquired 3 rolls (40 ft each) of indoor 300 ohm
coax, a closeout at Radio Shack. On checking my house
diagram (drawing), I determined that I could run another
antenna which could run about 100 feet if I include my
garage. This is measured from left rear roof, through a
wall, diagonally to front right garage (plus a 20 ft wrap on
each end).

I'd welcome any suggestions from the group on an antenna
configuration such as dipole, folded dipole, twinlead
converted to long wire (doubled back on itself), etc. This
would be for SW reception, but MW would be a plus. Thanks.

You could take two of those 40 foot pieces and make a 80 foot
folded dipole antenna.

Yes. The resonant frequency of an (un)folded dipole of 80 ft
would be about 5.85 Mhz. My current antenna (resonant at 14.18
Mhz) uses a twinlead stub which supposedly confers a broader
bandwidth. I have used it to monitor 160 meters and works fairly
well in the single digits. Is there a formula for calculating
stub length to give this 80 footer greater bandwidth?

According to a Joe Carr antenna book I have this:
In meters
A - 141.8 / F MHz - Over all length or distance between outer shorts
B - 122 / F MHz - distance between inner shorts

In addition you could leave the outer shorts open then it would be:
A - 142 / F MHz - Over all length or distance between outer ends
B - 122 / F MHz - distance between inner shorts

Example for 9.75 MHz is
A = 14.56 meters
B = 12.51 meters

Some of the Radio Shack 300 / 75 ohm transformers are not much
good below 10MHz.

Interestingly, I acquired the transformers (2 on a card) at the
local dollar store. Works fine.

Well, it depends on which one you got your hands on. On some the
S21 falls off below 10MHz and you were talking about a lower
frequency antenna so just watch out for that.


What is meant by inner and outer 'shorts'?

If you use 300 ohm line to make the folded dipole then you "short" the
two conductors on the ends.

There are two designs above I wrote about. The first is a folded dipole
so the ends are shorted and in order to make it more broadband you add
two more shorts between the conductors a specific distance from the
center.

The second design only has the shorts placed at the "B" distance and the
ends are left open.

--
Telamon
Ventura, California

(B Williams) wrote in message . com...
"HankG" no_one@invalid wrote in message ...
My primary antenna is a 33 ft folded dipole made from 300 ohm twin lead and
is mounted in my roof. It is coupled by a 300 to 75 ohm tv transformer to
75 ohm coax. The antenna is described in message 2471 of the Yahoo Rx-320
group and works fairly well.

Recently, I acquired 3 rolls (40 ft each) of indoor 300 ohm coax, a closeout
at Radio Shack. On checking my house diagram (drawing), I determined that I
could run another antenna which could run about 100 feet if I include my
garage. This is measured from left rear roof, through a wall, diagonally to
front right garage (plus a 20 ft wrap on each end).

I'd welcome any suggestions from the group on an antenna configuration such
as dipole, folded dipole, twinlead converted to long wire (doubled back on
itself), etc. This would be for SW reception, but MW would be a plus.
Thanks.

HankG


Forget about using the 300 ohm coax. Do yourself a favor if you want
good receiving antenna. Go to Home Depot and purchase a roll of 14
gauge insulated wire, some screw-type eye bolts and two copper
plating ground rods and quad shielded RG-6 coax. Then build an
EWE antenna. It is one of the quietest antenna you can construct.
And has fantastic results. Check the web for them.


BW

As for building an EWE, you are only partially correct about cut for
one or two bands.
If you modify some of the properties of the construction. You can
extend it's range.
I am usre most of the articles you have read state dimension such as
10 feet in
height by 50 to 80 feet in length. And yes if you keep at one
directional point it
does restrict reception based in it's orientation.

By using a fence in the backyard. I have an EWE that is 5 feet in
height by 180 feet in length. Wrapping all the way around the backyard
fence. Running N-S, E-W and S-N. Attached at the termination point for
the lead in coax, RG-6 Quad shielded burial type to a 16:1 balun.
Between the ground rods for each end. From a terminal strip I have
placed a ferrite core. Wrapped the 14 gauge insulated four times then
terminating the ground rod.

The second EWE is 5 feet by 40 feet orientated N-S. It has been
terminated to
ICE 180. This mostly used if the signals are strong, versus the other
for very
weak stations.

Unless the band conditions are at major storm levels,
propogation-wise. Or there are local thunderstorms. I have no static
build-up on either antenna. Which is a problem with other types of
wire antennas. There is far more flexibility with this arrangement.

Having tried dipoles, end-terminated, slopers and active antennas. The
EWE out
performs each of the above. They pull stations out of the noise the
others mentioned can not even lock on to.

Keep in mind that this type of antenna is somewhat in between a loop
and beverage type antenna. As for the comment about EWE in an attic.
Why not, you could still take the ends out the ground rods. It is
certainly feasible.


bw

BW,

My comment on the EWE In-the-Attic.
[My Bad :]

Actually if a section of the Attic has a
straight run (line) Peak-to-Peak with out-side Walls and Cover Eaves.
A Ground Rod could be place at the base of one Wall and a Wire Antenna
Element run up the Wall to the Peak. Drill a Hole and use an Insulator
in the Wall near the Peak under the Eaves. Run the Wire through the
Attic to the other Peak and do the same thing in Reverse on the other
side Wall.
and you be eweing in-the-attic on a saturday night ~ RHF
..
..