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-   -   "Miracle" DLM RI short vertical (https://www.radiobanter.com/antenna/2185-%22miracle%22-dlm-ri-short-vertical.html)

Jimmie August 23rd 04 09:35 PM


"Richard Clark" wrote in message
...
On Mon, 23 Aug 2004 03:01:53 GMT, "Jimmie"
wrote:

I was under the impression that radiation efficency was pretty much a"
no-brainer".If the antenna is built of quality materials with good
workmanship the antenna would be an efficent radiator with little ohmic

or
dielectric losses. The exception to this of course would be antennas that
use an earth ground. I just found I was losing at least 3 db to heating

up
the ground.


Hi Jimmie,

3dB heating up the ground with an antenna that has 5dBi gain in the
preferred direction and launch angle compared to an antenna that has
no ground and 0dBi gain in the same preferred direction and launch
angle may give you pause and allow the worms some comfort on a cold
day.

Workmanship and quality materials tests those reputations vastly more
for smaller antennas than standard sized ones. Those 1 meter loops
used for HF are not rated for the lower bands for very good reasons,
and they claim (and I believe them) high standards for their product.
However, if you could resonate them in the 160M band, you'd be lucky
to see 1% efficiency.

Small antennas carry a lot of baggage, and any claims of efficiency
superior to the standard antennas they replace are suspect. When they
qualify that efficiency in creative terms like "more efficient per
unit length" you would do well to skip that and ask for field
strengths out 10 miles. A model called the eh had an FCC style site
survey performed to which they crowed it proved their design was equal
or better to a full size antenna. The data revealed results 10 and 20
miles out were 15-17dB down below that same standard they were so much
more efficient than.

73's
Richard Clark, KB7QHC


Is this radiation efficency or gain, y'all are talking about. Not familar
with the DLM but sounds like the MFJ loop. 10 db pad and a cb antenna would
work as good.



Jimmie August 23rd 04 09:54 PM


"Yuri Blanarovich" wrote in message
...

I was under the impression that radiation efficency was pretty much a"
no-brainer".If the antenna is built of quality materials with good
workmanship the antenna would be an efficent radiator with little ohmic

or
dielectric losses. The exception to this of course would be antennas that
use an earth ground. I just found I was losing at least 3 db to heating

up
the ground.

Jimmie




Keep digging, you will find more lost dBs. Things get aggravated in loaded
antennas when you start inserting coils, loading elements, folding them

back,
etc. Efficiency is roughly proportional to the area under the current
distribution curve along the radiator. That can be affected by any of the
shortening "miraculous" gizmos, like Vincent DLM antenna. It is not just

heat
loses in resistances. You can't have "perfectly" conducting piece of 1 ft
copper tubing be as effcient as 130 ft full size radiator on 160m.
Getting smarter, Eh ? :-)

Yuri, K3BU

Yep, pretty much a "no brainer " the antenna you discribed is crap.



Richard Clark August 23rd 04 11:15 PM

On Mon, 23 Aug 2004 20:35:27 GMT, "Jimmie"
wrote:

Is this radiation efficency or gain, y'all are talking about.


The eh antenna (a Georgia special - y'all got the accent right).
Not familar
with the DLM but sounds like the MFJ loop.


More a fractal gone bad, if in fact that isn't repetitive.

10 db pad and a cb antenna would
work as good.


probably better - and be patented in the next year without disclosure
of your "prior art."

73's
Richard Clark, KB7QHC

Jerry Martes August 24th 04 01:20 AM


"Yuri Blanarovich" wrote in message
...

I was under the impression that radiation efficency was pretty much a"
no-brainer".If the antenna is built of quality materials with good
workmanship the antenna would be an efficent radiator with little ohmic

or
dielectric losses. The exception to this of course would be antennas that
use an earth ground. I just found I was losing at least 3 db to heating

up
the ground.

Jimmie




Keep digging, you will find more lost dBs. Things get aggravated in loaded
antennas when you start inserting coils, loading elements, folding them

back,
etc. Efficiency is roughly proportional to the area under the current
distribution curve along the radiator. That can be affected by any of the
shortening "miraculous" gizmos, like Vincent DLM antenna. It is not just

heat
loses in resistances. You can't have "perfectly" conducting piece of 1 ft
copper tubing be as effcient as 130 ft full size radiator on 160m.
Getting smarter, Eh ? :-)

Yuri, K3BU


Yuri

I wonder where the power into a perfectly conducting 1 foot length of
copper tubing goes if it doesnt get either radiated or get converted to
heat. Can you tell me how the short (1 foot) copper tube looses the power
it receives from its power source?

Jerry



Ed Price August 24th 04 11:28 AM


"Jerry Martes" wrote in message
news:8RvWc.550$%11.374@trnddc02...

"Yuri Blanarovich" wrote in message
...

I was under the impression that radiation efficency was pretty much a"
no-brainer".If the antenna is built of quality materials with good
workmanship the antenna would be an efficent radiator with little ohmic

or
dielectric losses. The exception to this of course would be antennas

that
use an earth ground. I just found I was losing at least 3 db to heating

up
the ground.

Jimmie




Keep digging, you will find more lost dBs. Things get aggravated in

loaded
antennas when you start inserting coils, loading elements, folding them

back,
etc. Efficiency is roughly proportional to the area under the current
distribution curve along the radiator. That can be affected by any of

the
shortening "miraculous" gizmos, like Vincent DLM antenna. It is not just

heat
loses in resistances. You can't have "perfectly" conducting piece of 1

ft
copper tubing be as effcient as 130 ft full size radiator on 160m.
Getting smarter, Eh ? :-)

Yuri, K3BU


Yuri

I wonder where the power into a perfectly conducting 1 foot length of
copper tubing goes if it doesnt get either radiated or get converted to
heat. Can you tell me how the short (1 foot) copper tube looses the power
it receives from its power source?

Jerry


This isn't answering your question, but you forgot the effect of reflected
power. I wouldn't call that "lost power", but it sure isn't contributing to
the radiation.

Ed
wb6wsn


Cecil Moore August 24th 04 12:22 PM

Ed Price wrote:
This isn't answering your question, but you forgot the effect of reflected
power. I wouldn't call that "lost power", but it sure isn't contributing to
the radiation.


Remember, a terminated Rhombic radiates essentially
in one direction. Removing the termination allows
reflections to take place thus also radiating in the
opposite direction, the direct result of radiation of
reflected power.
--
73, Cecil http://www.qsl.net/w5dxp



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k4wge September 14th 04 02:09 PM

Cecil Moore wrote in message

Remember, a terminated Rhombic radiates essentially
in one direction. Removing the termination allows
reflections to take place thus also radiating in the
opposite direction, the direct result of radiation of
reflected power.


http://www.uri.edu/news/vincent/boxboro_files/frame.htm

Richard Clark September 14th 04 06:08 PM

from the revolutionary conceptualist:
"The term radiation resistance is a carry over from the very
early days of radio and was used as a book keeping method to
satisfy at that time the laws of physics."

from the early days (1907) of radio:
R = (1600 · h² / wavelength²) · Ohms

Substituting the known h (12 feet) and the known wavelength (40M) to
"satisfy at that time the laws of physics":
R = 9 Ohms

from the revolutionary conceptualist:
"THE FAILURE MECHANISN WAS ...
FROM IxR LOSS ... EVEN WITH LOW
POWER (100 WATTS)"
....
"THIS MEANS THAT THE HELIX AND THE LOAD COIL WILL NOT
DISSIPATE ANY APPARENT POWER AND THE ONLY POWER
DISSIPATED WILL BE I x R POWER OR JUST THE LOSS OF
POWER CREATED FROM RESISTANCE OF THE LOAD COIL
WINDING. (i. e. resistance of the wire)"

And as for those fraudtenna legal concepts:
"THIS IS PATENT PENDING TECHNOLOGY
...
DOING ANY OF THE ABOVE WILL INFRINGE ON THE PATENT AND RESULT
IN LEGAL CONSEQUENCES FAR GREATER THAN YOU MAY EXPECT"

:-)

k4wge September 16th 04 10:01 PM

Richard Clark wrote in message . ..

http://www.uri.edu/news/vincent/boxboro_files/frame.htm


from the revolutionary conceptualist:
"The term radiation resistance is a carry over from the very
early days of radio and was used as a book keeping method to
satisfy at that time the laws of physics."

from the early days (1907) of radio:
R = (1600 · h² / wavelength²) · Ohms

Substituting the known h (12 feet) and the known wavelength (40M) to
"satisfy at that time the laws of physics":
R = 9 Ohms

from the revolutionary conceptualist:
"THE FAILURE MECHANISN WAS ...
FROM IxR LOSS ... EVEN WITH LOW
POWER (100 WATTS)"
....
"THIS MEANS THAT THE HELIX AND THE LOAD COIL WILL NOT
DISSIPATE ANY APPARENT POWER AND THE ONLY POWER
DISSIPATED WILL BE I x R POWER OR JUST THE LOSS OF
POWER CREATED FROM RESISTANCE OF THE LOAD COIL
WINDING. (i. e. resistance of the wire)"

And as for those fraudtenna legal concepts:
"THIS IS PATENT PENDING TECHNOLOGY
...
DOING ANY OF THE ABOVE WILL INFRINGE ON THE PATENT AND RESULT
IN LEGAL CONSEQUENCES FAR GREATER THAN YOU MAY EXPECT"

:-)


Do you suppose he is getting legal advice from FAS?

Yuri Blanarovich September 16th 04 10:11 PM


And as for those fraudtenna legal concepts:
"THIS IS PATENT PENDING TECHNOLOGY
...
DOING ANY OF THE ABOVE WILL INFRINGE ON THE PATENT AND RESULT
IN LEGAL CONSEQUENCES FAR GREATER THAN YOU MAY EXPECT"

:-)


Do you suppose he is getting legal advice from FAS?



Freak should hire him, or they should merge :-)
Pending technolgy, my aas, this crap is 60 years old.
One more big joke and bad image of decent hams.
Mr. DLM should stick with fixing cafeteria equipment and leave the antenna
"business" alone.


Yuri K3BU.us


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