The T2FD style antennas are most popular for NVIS communication, where
the intent is to transmit and receive nearly straight up and back down
within a few hundred miles on freqs generally lower than 12MHz. The T2FD
does this best at lower elevations where it’s less than .25 wavelength
above ground at highest operating frequency. It’s gained popularity with
military frequency hopping and ALE stations because of it’s instant
broad band charm. With that said, one problem I see is placing the
antenna in the attic will put house wiring right underneath the antenna,
causing the pattern to point mostly up and not at a low angle to the
horizon where you want it for SWL DX (same for any horizontal ant in the
attic). It will also be more susceptible to RFI from stuff within the
house. The T2FD is generally a low noise antenna and it also requires
about a 16:1 balun, not a 4:1. You will seriously degrade the
performance if you try to feed it with anything less than the difficult
to obtain 16:1 flavor.
Bob


N9NEO wrote:
Ok, Thanks for the good links.

If you explain the twist..... so I can understand. I don't think you
are telling me to just build a T2FD and make the feed point horizontal.
You are telling... Ok, I think I got it... So the loop will actually
go thru a 180 degree spin I think. is what you are telling me.

Yes, biggest problem was that roof wasn't high enough the last time I
was up there. I can stand up in it no prob and last weekend daughter's
BF and I laid a 24" wide path of plywood down the full 45 foot length.

Ok, I'll give this a try and see how it works out. I got some #43 ring
cores that I was going to build a 4:1 balun on. I may get bored one
day and fire up a transmitter into this setup, so I'll wind a few turns
on it so I don't smoke it.

thanks again
Bob

Bob,

N9NEO {Bob} has the #43 Ferrite for building his own
Baluns so a 4:1, 9:1 or 16:1 should not be a problem.

4:1 (2T-to-1T) = 24 Turn Primary Antenna Windings
and 12 Turns Secondary Coax Cable Windings

9:1 (3T-to-1T) = 30 Turn Primary Antenna Windings
and 10 Turns Secondary Coax Cable Windings

16:1 (4T-to-1T) = 32 Turn Primary Antenna Windings
and 8 Turns Secondary Coax Cable Windings

The other Part of the T2FD is the Terminating Resistor
and an In-the-Attic T2FD Antenna may require some
Adjustment {Play-With} the Terminating Resistor to
get the Antenna to yeild the All-Band Coverage that
is sought from the T2FD Antenna.

more to think about - iane ~ RHF