On Dec 10, 6:04 pm, wrote:
On Dec 11, 12:49 am, RHF wrote:



On Dec 10, 4:13 pm, wrote:

I suspected there are many people who lurk but will never post in a
public arena.
After my experiences with a cyber-stalker I can understand their
hesitance.

A SWL in Scotland asked me about a comment I made regarding antennas
in
one of my RFI diatribes.

Sorry for the delay, but I ran this past some friends of varying
technical skill levels,
to insure that first my answers are technically accurate, and as
simple as I can get,
while maintaining accuracy.

Get the wood out to start the fire to burn me at.

There are really only three types of HF antennas.
Dipoles
Loops
Surface or Traveling wave.

Of these, only the Traveling wave antenna relies on the earth below it
for it't basic
operation. Dipoles will be effected by the presence of the earth below
them, but a
dipole will operate just fine in free space. Loops are somewhat less
effected by
the earth, but they to will operate just fine in free space.

A traveling wave antenna, beverage or 'long wire' relies on the soil
below the elevated conductor. For most of us Beverages and true 'long
wires' for anything
below 30MHz isn't practical. We simply don't have the real estate
needed to
erect one.

Loops are loops. Many people swear by them, but I have yet to be
impressed.
If you must have a loop investigate the WL1030 as it compares very
well to
the famed Wellbrook ALA1530. I owned a for a few weeks and in a head
to
head test with the WL1030 the WL1030 was always as good as or better
then
the ALA1530. The WL1030 specifies a hard to find Litz wire that
shouldn't stop
anyone. I tried the specified Litz wire and a solid and a stranded
wire and I
couldn't tell any difference. It is true that I didn't do extensive
tests below MW.
I am not into NDBs.

The typical 50 to 100' random wire is barely a longwire antenna at
10M, but at
2M, 146, it is a true longwire. But it is also an extremely poor
antenna at those frequencies.

Now for the part that labels me a Apostate.

-
- The random wire antenna many of us use is a dipole in disguise.
- The elevated wire is the obvious element.
- The earth is the non obvious element.
- The earth is generally a very poor conductor
- and also has significant reactance.
-

Hence the Far-End-Fed Inverted "L" Antenna

# 1 - One-Half - The Horizontal part of the 'elevated'
Wire Antenna Element (-) is above the surface of the ground.

Note - Grounding Point (g) at the Far-End-Fed Point
using a Ground Rod mounted Matching Transformer (M%T).

# 2 = The-Other-Half = The Horizontal part of the
'on-the-ground' Coax Cable (=) is On-the-Ground or
Buried-under-the-Ground directly under the elevated
Wire Antenna Element. {Unifying the Ground below it}

-Sort-of-Like- a Crude End-Fed-Dipole

x-----------------------------o
|
|
|
M%T===========================RX
-g-

IMHO - Generally works better than a Near-End-Fed
Inverted "L" Antenna. ~ RHF
.


- If I understand your diagram, the feedline, be it coax
- or balanced, either has a transformer or is directly
- connected so the antenna feeds the center of the coax
- or one side of the balanced line and the braid or other
- side connected to ground.

Yes - That is correct.

- If the condition I describe is accurate, then the "L"
- is the obvious dipole element,

Yes - That is correct.

- and the ground is the other, non obvious, dipole element.

Yes - That is correct.

- I bet if you lifted the ground and duplicated the obvious
- visible "L" with a similar "L" you will get much better
- reception.

Yes - But that would become a more 'Balanced' Dipole Antenna
and thus more Frequency "Specific' as well.

- The earth is almost always a very poor conductor.

Yes - That is "The Why" of running the Coax Cable 'directly'
under the Wire Antenna Element.
{Unified Ground from End-to-End -aka- Single Ground Radial
-aka2- Single Counterpoise}

- Unless you live in a salt marsh, there are many better options.

-idk- {I Don't Know}

- A ground should be viewed as something needed to drain static
- or energy from a nearby lightning strike, not a active part
- of the antenna system.

Except for 'Balanced' Antenna Systems : All 'other' Antennas
are "In-Fact" Antenna-and-Ground Systems.

- When was the last time you had to ground a set of VHF
- rabbit ears for the antenna to work?

-idrw- {I Don't Remember When}
-because- A Set of VHF Radio Ears is a "Balance" Dipole Antenna :
Which in-and-of-itself does not require a Ground to function
very well as a "Balance" Dipole Antenna.

- I suspect that because radio started before there were
- widespread man made RF noise sources, and the "L" antenna
- you describe worked very well even with the poor ground
- conductivity.

The Far-End-Fed Inverted "L" Antenna works very well today
-wrt- many other Antennas which work 'less-well' today.

- In today's noisy world it is seldom the best, or even an
- acceptable option.

Alas 'our' Experiences are different and annadotal.
Neither Is Wrong - Just Different.
You Being You There -and- Me Being Me Here.

- And before you ask, yes I have the parts on hand to erect
- an emergency "L" antenna in the event my nice and fancy
- active dies and I need to listen in a hurry.

It is always good to "Be Prepared" for the What-Ifs )

Note - I wrote about a "Bad Weather" small Dipole Antenna
to use with Batteries for Shortwave Listeners (SWLs)

READ - For Shortwave Listeners (SWLs) :
Which is Better to Use ? a FM Folded Dipole Antenna ?
-or- a Whip Antenna ?
http://www.google.com/group/rec.radi...f659bde87e6a75
http://groups.yahoo.com/group/Shortw.../message/14026

- Of course I also have a trap dipole that I could erect
- in a hurry for my ham radio transceiver. I really don't
- expect any emergencies, but given the ice storms hitting
- the mid west, you never know.

Yes - You Never Know )

- Terry

iane ~ RHF