Any feed back?

If you desire a single antenna with excellent SWR match at many bands, then I
am of the opinion that there is value here.

Even the most efficient horizontal dipole is almost useless for DX--the assumed
need, not NVIS-- unless it is high up. This is because all low dipoles have low
gain at low elevations: Their launch angle is quite high.

I would suspect that typical ohmic losses on the BW are 2-5 dB. The mismatch
lsses are negligible.

Getting this well over a wave high at the lowest freq of operation will afford
at least that, and probably more, in a gain differential at low angles,
compared to an efficient, low dipole.

The point: a high BW antenna will work well. Any low dipole will work poorly.
The in-between is a valid issue to ponder.

73,
Chip N1IR

"Fractenna" wrote in message
...
Any feed back?

If you desire a single antenna with excellent SWR match at many bands,
then I
am of the opinion that there is value here.

Even the most efficient horizontal dipole is almost useless for DX--the
assumed
need, not NVIS-- unless it is high up. This is because all low dipoles
have low
gain at low elevations: Their launch angle is quite high.

I would suspect that typical ohmic losses on the BW are 2-5 dB. The
mismatch
lsses are negligible.

Getting this well over a wave high at the lowest freq of operation will
afford
at least that, and probably more, in a gain differential at low angles,
compared to an efficient, low dipole.

The point: a high BW antenna will work well. Any low dipole will work
poorly.
The in-between is a valid issue to ponder.

73,
Chip N1IR

Chip, how did we digress to comparing a "high B&W" to a "low dipole"? When
the two are each at their optimal height (and why would we ever compare
anything else..) then the dipole has it all over a B&W. I use my (amost 1/2
wave height) dipole only for DX, without a tuner on it's two resonant
frequencies and with a tuner on two bands well above, with amazing results.
5, 8, 11 and 15 mhz to Alaska, Equador, Venezuela and Canadian Maritimes, if
that qualifies as "DX".

73

Jack Painter
Virginia Beach, Va

Chip, how did we digress to comparing a "high B&W" to a "low dipole"? When
the two are each at their optimal height (and why would we ever compare
anything else..) then the dipole has it all over a B&W. I use my (amost 1/2
wave height) dipole only for DX, without a tuner on it's two resonant
frequencies and with a tuner on two bands well above, with amazing results.
5, 8, 11 and 15 mhz to Alaska, Equador, Venezuela and Canadian Maritimes, if
that qualifies as "DX".

73

Jack Painter
Virginia Beach, Va


Hi Jack,

It seems relevant to me in two big contexts: (1) why do some folks do well
(relatively) with the BW antenna; (2) what does it replace?

My response clearly explains (1). In the case of (2), I can think of many
circumstances where it is preferable to put one dipole (BW) up high than a slew
of dipoles up high. If you have neighbors, you know what I mean:-)

Don't know what DX is to me anymore; I have DXCC #1 Honor Roll and haven't been
active on the low bands in several years. To someone else, DX is what you
haven't heard or worked yet:-) I say go for it.

Some folks don't live in a perfect world, Jack, and its good to know when a
compromise is a true degradation.

A BW antenna, up high, is a good antenna for DX across many bands. It is hardly
a dummy load.

Hope this helps on this question.

73,
Chip N1IR

"Fractenna" wrote

Chip, how did we digress to comparing a "high B&W" to a "low dipole"?
When
the two are each at their optimal height (and why would we ever compare
anything else..) then the dipole has it all over a B&W. I use my (amost
1/2
wave height) dipole only for DX, without a tuner on it's two resonant
frequencies and with a tuner on two bands well above, with amazing
results.
5, 8, 11 and 15 mhz to Alaska, Equador, Venezuela and Canadian Maritimes,
if
that qualifies as "DX".

73

Jack Painter
Virginia Beach, Va


Hi Jack,

It seems relevant to me in two big contexts: (1) why do some folks do well
(relatively) with the BW antenna; (2) what does it replace?

My response clearly explains (1). In the case of (2), I can think of many
circumstances where it is preferable to put one dipole (BW) up high than a
slew
of dipoles up high. If you have neighbors, you know what I mean:-)

Don't know what DX is to me anymore; I have DXCC #1 Honor Roll and haven't
been
active on the low bands in several years. To someone else, DX is what you
haven't heard or worked yet:-) I say go for it.

Some folks don't live in a perfect world, Jack, and its good to know when
a
compromise is a true degradation.

A BW antenna, up high, is a good antenna for DX across many bands. It is
hardly
a dummy load.

Hope this helps on this question.

73,
Chip N1IR

Hi Chip,

Yes it does help to hear it works reasonably well when other circumstances
limit the options. I can't for instance squeeze more long dipoles up, but I
could try one of the T2 varieties someday. Since the dipole I now have works
across many bands well with a tuner, the B&W could never replace it, but it
might augment it someday.

Cheers and thanks,

Jack Painter
Virginia Beach, Va

With all the hoopla going on for this antenna I was surprised that no
one reported any calculated antenna efficiencies. So I modeled the
antenna in free space - to remove environmental influences other than
those contained within the antenna itself (terminating resistor and
wire loss) - NEC reported the following:

Freq. MHz. Efficiency Average Gain Peak Gain
MHz % DBi DBi

3.5 9.6 -10.43 -8.49
7.15 41.24 -3.85 -1.33
14.2 23.21 -6.36 -1.59
21.2 30.01 -5.23 -1.36
29 53.81 -2.69 2.17

73
Danny, K6MHE

Freq. MHz. Efficiency Average Gain Peak Gain
MHz % DBi DBi

3.5 9.6 -10.43 -8.49
7.15 41.24 -3.85 -1.33
14.2 23.21 -6.36 -1.59
21.2 30.01 -5.23 -1.36
29 53.81 -2.69 2.17

73
Danny, K6MHE


80M is a bit lower than I expect, but not by much:referring to dBmax values. It
probably picks up a dB or more at the high end of 75M.

It doesn't mean much to discuss 'average gain' values unless its an isotropic
or (within a certain elevation range) an omni antenna. Sometimes vertical
dipoles are described as having an 'average gain', but I haven't seen that
used for horizontal ones:-)

The pattern is not bidirectional on the higher bands BTW... ar least that's
what intuition tells me...

73,
Chip N1IR