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Old December 1st 04, 05:17 PM
HankG
 
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Default antenna suggestion

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





  #2   Report Post  
Old December 2nd 04, 05:21 AM
Telamon
 
Posts: n/a
Default

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.

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

--
Telamon
Ventura, California
  #3   Report Post  
Old December 2nd 04, 12:40 PM
HankG
 
Posts: n/a
Default


"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?

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.


HankG


  #4   Report Post  
Old December 3rd 04, 05:27 AM
Telamon
 
Posts: n/a
Default

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.

--
Telamon
Ventura, California
  #5   Report Post  
Old December 3rd 04, 12:39 PM
HankG
 
Posts: n/a
Default


"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'?

HankG





  #6   Report Post  
Old December 3rd 04, 12:44 PM
dxAce
 
Posts: n/a
Default



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.

dxAce
Michigan
USA


  #7   Report Post  
Old December 4th 04, 12:21 AM
B Williams
 
Posts: n/a
Default

"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
  #8   Report Post  
Old December 4th 04, 01:33 AM
Brian
 
Posts: n/a
Default

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.



lol!

-Brian
/lives in the hood


  #9   Report Post  
Old December 4th 04, 02:17 PM
HankG
 
Posts: n/a
Default


"B Williams" wrote in message
om...
"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.

On your suggestion, I've started to do some investigating of EWE antennas.
My (land) plot may not be the best. What I've read so far, seems to suggest
that EWEs are more or less confined to 1 or 2 bands. I need something that
is broadband (HF); MW and LW would be a plus. (dream on?). Is there such a
thing as a broadband EWE?

HankG



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