Query..
 

I have about 40 feet of garden to erect an antenna....Could anyone tell
me if I took 2 20 feet length of twin ladder and shorted the ends
fed one side of the dipole with twin ladder and connected a 52 ohm
resistor across the other side so the tx would see a match would be
better than feeding a 40 foot endfed through an atu...
My thinking is that most of the small antenna on the market are just
dummy loads with a small amount of wire attached and appear to work so
would my 40 feet work better.. ??





--
Regards
Ted Wager
Using Debian Linux

Query..
 

Ted wrote:
I have about 40 feet of garden to erect an antenna....Could anyone tell
me if I took 2 20 feet length of twin ladder and shorted the ends
fed one side of the dipole with twin ladder and connected a 52 ohm
resistor across the other side ...

Where is the ground for that 52 ohm resistor?
--
73, Cecil, http://www.qsl.net/w5dxp

Query..
 

Where is the ground for that 52 ohm resistor?
--
73, Cecil

=========================================

Really Cecil, you shouldn't ask awkward questions like that.

You might gain the reputation of being a wicked troller.

On the other hand, it cannot be denied, your question is apt and could
be considered to be educational. Please continue!

Due to a certain person who ought to know better, I suffer from the
same misinterpretation of motives myself. smiley
----
Reg.

Query..
 

I'm a bit confused by your description. Is this a folded dipole, 40
feet long, with an added resistor in the conductor which would normally
be unbroken, inserted directly opposite the feedpoint? Or is it
something else? Why not just a 40-foot-long center-fed doublet, with a
tuner at the transmitter end? What bands do you want to use your
antenna on? What do you want to accomplish with it? (DX, local,
intermediate range, ...)

Cheers,
Tom

Query..
 

Cecil Moore wrote:

Ted wrote:
I have about 40 feet of garden to erect an antenna....Could anyone tell
me if I took 2 20 feet length of twin ladder and shorted the ends
fed one side of the dipole with twin ladder and connected a 52 ohm
resistor across the other side ...

Where is the ground for that 52 ohm resistor?

The feed goes to the centre..The ends are strapped together and the resistor
connects between the free ends opposite the feed connection...
--
Regards
Ted Wager
Using Debian Linux

Query..
 

Ted wrote:

Cecil Moore wrote:

Ted wrote:
I have about 40 feet of garden to erect an antenna....Could anyone tell
me if I took 2 20 feet length of twin ladder and shorted the ends
fed one side of the dipole with twin ladder and connected a 52 ohm
resistor across the other side ...

Where is the ground for that 52 ohm resistor?

The feed goes to the centre..The ends are strapped together and the resistor
connects between the free ends opposite the feed connection...

I'm afraid we need a schematic. Is this correct?

20ft 20ft
+-------------------FP------------------+
| 52 ohm resistor
+-------------------FP------------------+

--
73, Cecil, http://www.qsl.net/w5dxp

Query..
 

Cecil Moore wrote:

Ted wrote:

Cecil Moore wrote:

Ted wrote:
I have about 40 feet of garden to erect an antenna....Could anyone tell
me if I took 2 20 feet length of twin ladder and shorted the ends
fed one side of the dipole with twin ladder and connected a 52 ohm
resistor across the other side ...

Where is the ground for that 52 ohm resistor?

The feed goes to the centre..The ends are strapped together and the
resistor connects between the free ends opposite the feed connection...

I'm afraid we need a schematic. Is this correct?

20ft 20ft
+-------------------resistor------------+ |
connected connected
+-------------------FP------------------+

Like so...Ends strapped and r at centre opposite feed...
--
Regards
Ted Wager
Using Debian Linux

Query..
 

Ted wrote:
I'm afraid we need a schematic. Is this correct?

20ft 20ft
+-------------------resistor------------+ |

connected connected

+-------------------FP------------------+

OK, close to a T2FD. Here are the formulas for such an antenna.

http://www.hard-core-dx.com/nordicdx.../t2design.html

Looks like yours would be resonant around 8.2 MHz.
--
73, Cecil, http://www.qsl.net/w5dxp

Query..
 

Cecil Moore wrote:

Ted wrote:
I'm afraid we need a schematic. Is this correct?

20ft 20ft
+-------------------resistor------------+ |

connected connected

+-------------------FP------------------+

OK, close to a T2FD. Here are the formulas for such an antenna.

http://www.hard-core-dx.com/nordicdx.../t2design.html

Looks like yours would be resonant around 8.2 MHz.

Thanks very much for the info and the address..
--
Regards
Ted Wager
Using Debian Linux

Query..
 

Ted wrote in news:43bd1032$0$82676
:




I have about 40 feet of garden to erect an antenna....Could anyone tell
me if I took 2 20 feet length of twin ladder and shorted the ends
fed one side of the dipole with twin ladder and connected a 52 ohm
resistor across the other side so the tx would see a match would be
better than feeding a 40 foot endfed through an atu...
My thinking is that most of the small antenna on the market are just
dummy loads with a small amount of wire attached and appear to work so
would my 40 feet work better.. ??

If you're looking for transmit efficiency, then a resistor is not going
to help you except to keep the standing waves down. You don't, in
practice want such a resistor to be dissipating more than about half your
power. Even that much is a three decibel loss (about half an S unit).

If it was my space, I'd start as high as I could get at one end and run a
sloping dipole with 300-ohm or 450-ohm feeder to the atu. Make sure your
atu has a 4:1 balun in it or get a balun that can give you at least this
ratio. And just feed the nice sloper on as many bands as you can tune
it! It won't be earth-shaking on 80m and will probably wimp out on 160,
but I bet it would be tolerably good on 40 and really decent on 30 and
up.

Dress the feedline away from the main wire at right angles and twist it a
bit. Make sure to follow proper line-dressing procedures where you bring
it into the house (or use a 4-1 balun and run coax the last bit). And
fiddle with the length of the lower arm of the dipole until you get no
common-mode antenna currents on the feeder, say on 30m. That should do
it.


--
Dave Oldridge+
ICQ 1800667