In article .com,
"RHF" wrote:

On Feb 15, 6:30 pm, Telamon
wrote:
In article .com,
"tom k in L.A." wrote:

On Feb 14, 7:57 pm, Telamon
wrote:
In article .com,
"tom k in L.A." wrote:

anyone use a t2fd here? i'm considering replacing my longwire with a
t2fd-- but i can't mount it on a slope-- will i be wasting my time
and
money?

It would be a good move. Sloping it is not important.

really? some people feel strongly about the sloping. elaborate
telamon-- if i can get 1/2 the reception you do i will be a happy
pappy!

This antenna originated as a ship broadband antenna where there are
stays that could be used as an antenna if insulated. The stays on a ship
slope. Generally for reception higher is better so I would nix the
sloping idea.

You can build a simple folded dipole antenna out of TV 300 ohm twin lead
and use a common 300 to 75 ohm BALUN. The TV/FM BALUN transformers are
not all created equal. Some are poor below 15MHz. The BALUN units with
more heft indicate a bigger core that will work well down into the AMBCB
band. The twin lead will not support itself so you could tie-wrap it to
nylon cord or rope. It would be good if the antenna was at least 40 foot
long and longer would be better.

If this works well for you then go to the trouble of building a larger
capture area antenna.


Telamon,

Yes 300 Ohm TV type Twin-Lead will work for a Quik-and-Dirty T2FD.
To simply construction - Instead of a single 450 Ohm Resistor in the
Center of the upper T2FD Antenna Element with the 4:1 Balun in the
Center of the Lower T2FD Antenna Element. Put a 220 Ohm Resistor
at each end of the Twin-Lead.

I would not use resistors at all. They are not desirable for a folded
dipole.

And Yes Again - You are right that the better quality 300 Ohm to
75 Ohm TV type Matching Transformers {Baluns} can work down
to at least 5 MHz and as you point out these are usually the larger
diameter ones which have a bigger Ferrite Cord, which is the key
performance difference, besides increasing the number of windings.

IIRC - John Doty wrote about using the Binocular Ferrite Cores from
TY type Matching Transformers and -re-winding them with more
windings to get better performance across the Shortwave (HF)
Bands and down into the AM/MW Band. - - - Searching . . .

You can more inductance with short lengths of wire with a binocular
core. They make excellent transmission line transformers.

--
Telamon
Ventura, California