Any comments on the effectiveness of one of these boosters?

Saw this on Ebay. Looks to be a type of fractal antenna.

http://www.ebay.com.au/itm/Mobile-An...item256574bf70

On 15 Jul 2011 08:35:31 +1000, "Dr Who"
<dead_letter_office@hotmail.com> wrote:

>Saw this on Ebay. Looks to be a type of fractal antenna.
>
>http://www.ebay.com.au/itm/Mobile-An...item256574bf70

Pure hype and absolute baloney. They do absolutely nothing useful
xcept look cool.

--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831-336-2558
# http://802.11junk.com jeffl@cruzio.com
# http://www.LearnByDestroying.com AE6KS

"Dr Who" <dead_letter_office@hotmail.com> wrote in message
news:4e1f6f33$1@dnews.tpgi.com.au...
>
> Saw this on Ebay. Looks to be a type of fractal antenna.
>
> http://www.ebay.com.au/itm/Mobile-An...item256574bf70

Can you spell Unrealistic Expectations?

Years ago we (I worked as lead for a major cell phone manufacture) ran
extensive real world and lab test of similar devices then billed as 'passive
repeaters'.

Motorola (if memory serves) published an extensive and detailed report on
their proof of performance test on a very similar device using a
representative sample of then existing 800 MHz hand sets.

The phase mouse milk comes to mind.

NotMe wrote:

>
> "Dr Who" <dead_letter_office@hotmail.com> wrote in message
> news:4e1f6f33$1@dnews.tpgi.com.au...
> >
> > Saw this on Ebay. Looks to be a type of fractal antenna.
> >
> > http://www.ebay.com.au/itm/Mobile-An...item256574bf70
>
> Can you spell Unrealistic Expectations?
>
> Years ago we (I worked as lead for a major cell phone manufacture) ran extensive real world and lab test of similar devices then billed as 'passive repeaters'.
>
> Motorola (if memory serves) published an extensive and detailed report on
> their proof of performance test on a very similar device using a
> representative sample of then existing 800 MHz hand sets.
>
> The phase mouse milk comes to mind.

I expected as much.

The only reason I asked is that I've been playing around with/made up fractal antennas (HD TV application) and they are pretty impressive considering their size.

So I wondered if this gizmo could act in some way as a passive reflector - seemed unlikely but had to ask.

"Dr Who" <dead_letter_office@hotmail.com> wrote in message
news:4e1f9a71@dnews.tpgi.com.au...
> NotMe wrote:
>
>>
>> "Dr Who" <dead_letter_office@hotmail.com> wrote in message
>> news:4e1f6f33$1@dnews.tpgi.com.au...
>> >
>> > Saw this on Ebay. Looks to be a type of fractal antenna.
>> >
>> > http://www.ebay.com.au/itm/Mobile-An...item256574bf70
>>
>> Can you spell Unrealistic Expectations?
>>
>> Years ago we (I worked as lead for a major cell phone manufacture) ran
>> extensive real world and lab test of similar devices then billed as
>> 'passive repeaters'.
>>
>> Motorola (if memory serves) published an extensive and detailed report on
>> their proof of performance test on a very similar device using a
>> representative sample of then existing 800 MHz hand sets.
>>
>> The phase mouse milk comes to mind.
>
> I expected as much.
>
> The only reason I asked is that I've been playing around with/made up
> fractal antennas (HD TV application) and they are pretty impressive
> considering their size.
>
> So I wondered if this gizmo could act in some way as a passive reflector -
> seemed unlikely but had to ask.

Know about fractals but not about fractal antennas,

I tired to find a link to the original Motorola report but NO JOY.

NotMe wrote:

>
> "Dr Who" <dead_letter_office@hotmail.com> wrote in message news:4e1f9a71@dnews.tpgi.com.au...
> > NotMe wrote:
> >
> > >
> >>"Dr Who" <dead_letter_office@hotmail.com> wrote in message
> > > news:4e1f6f33$1@dnews.tpgi.com.au...
> > > >
> >>> Saw this on Ebay. Looks to be a type of fractal antenna.
> > > >
> >>> http://www.ebay.com.au/itm/Mobile-An...item256574bf70
> > >
> > > Can you spell Unrealistic Expectations?
> > >
> > > Years ago we (I worked as lead for a major cell phone manufacture) ran extensive real world and lab test of similar devices then billed as 'passive repeaters'.
> > >
> > > Motorola (if memory serves) published an extensive and detailed report on
> > > their proof of performance test on a very similar device using a
> > > representative sample of then existing 800 MHz hand sets.
> > >
> > > The phase mouse milk comes to mind.
> >
> > I expected as much.
> >
> > The only reason I asked is that I've been playing around with/made up fractal antennas (HD TV application) and they are pretty impressive considering their size.
> >
> > So I wondered if this gizmo could act in some way as a passive reflector - seemed unlikely but had to ask.
>
> Know about fractals but not about fractal antennas,
>
> I tired to find a link to the original Motorola report but NO JOY.


If you're interested in fractal antennas, here's a good site.

http://www.bobmc.net/doku2/doku.php?...indoor_antenna

I used the template to make up an eight element antenna for HD TV and it is very effective. I made the original four element first, but the eight is much better on signal strength.

I printed out the template onto paper (x 4), glued them onto cardboard and then stuck 1 mm copper wire onto the outline with sticky tape. Soldered in a couple of links and attached a balun and voila, top little antenna.

This is not suitable for wifi, however there are designs which supposedly work in the wifi band.

Interesting concept and quite a bit of information on the subject if you care to google.

On 15 Jul 2011 19:14:10 +1000, "Dr Who"
<dead_letter_office@hotmail.com> wrote:

>http://www.bobmc.net/doku2/doku.php?...indoor_antenna

No numbers. Oh well.

Gain, size, bandwidth. Pick any two.

<http://en.wikipedia.org/wiki/Fractal_antenna>

The problem with small fractal antennas is that they emphasize the
small size aspect, and end up compromising the others. The antenna in
the photo is vaguely similar to a bow tie antenna, which is basically
a wide band dipole. At frequencies less than the equivalent
(stretched out wire) dipole of the fractal antenna, the area between
the elements looks like a solid sheet of metal. At higher
frequencies, the bends start looking like RF chokes. The small sizes
have allegedly been benificial in cramming antennas into cell phones,
but as near as I can determine, acceptance seems to be the exception
rather than the rule.

The best proof is usually an NEC model. 4NEC2 has about 5 sample
antennas included, that are fractals.
<http://home.ict.nl/~arivoors/>

I blundered into this Koch fractal antenna analysis.
<http://www.akademik.unsri.ac.id/download/journal/files/scipub/ajas5121804-1807.pdf>
More:
<http://www.radio-astronomy.org/library/Fractal%20Antenna.pdf>
etc.

Drivel: An old rule-of-thumb in antenna design is that the uglier the
antenna, the better it works I've often suspected that fractal
antennas are proof of this rule.

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Jeff Liebermann wrote:

> On 15 Jul 2011 19:14:10 +1000, "Dr Who"
> <dead_letter_office@hotmail.com> wrote:
>
> > http://www.bobmc.net/doku2/doku.php?...indoor_antenna
>
> No numbers. Oh well.
>
> Gain, size, bandwidth. Pick any two.
>
> <http://en.wikipedia.org/wiki/Fractal_antenna>
>
> The problem with small fractal antennas is that they emphasize the
> small size aspect, and end up compromising the others. The antenna in
> the photo is vaguely similar to a bow tie antenna, which is basically
> a wide band dipole. At frequencies less than the equivalent
> (stretched out wire) dipole of the fractal antenna, the area between
> the elements looks like a solid sheet of metal. At higher
> frequencies, the bends start looking like RF chokes. The small sizes
> have allegedly been benificial in cramming antennas into cell phones,
> but as near as I can determine, acceptance seems to be the exception
> rather than the rule.
>
> The best proof is usually an NEC model. 4NEC2 has about 5 sample
> antennas included, that are fractals.
> <http://home.ict.nl/~arivoors/>
>
> I blundered into this Koch fractal antenna analysis.
> <http://www.akademik.unsri.ac.id/download/journal/files/scipub/ajas5121804-1807.pdf>
> More:
> <http://www.radio-astronomy.org/library/Fractal%20Antenna.pdf>
> etc.
>
> Drivel: An old rule-of-thumb in antenna design is that the uglier the
> antenna, the better it works I've often suspected that fractal
> antennas are proof of this rule.


Interesting subject and good links.

This one refers to wifi application.

http://www.jpier.org/PIER/pier104/15.10032003.pdf

Looks like a possibility for a DIY project.

Incidentally in regard to my original posting about the stick on "booster", it got me thinking about passive repeaters and I tried hooking two directional antennas together to see how they would work as a passive repeater (54G and 1 metre cable length).

I was interested to see what sort of losses could be expected.

Basically I had a biquad outside of my brick garage with large metal door (no signal inside) garage and a 60 degree patch antenna inside, accessed by my laptop.

The signal from the house was about 65 dBm.

It did allow the signal to be accessed in the garage at low strength and speed (max of 11 Mbyte/sec).

The setup looked to be pretty inefficient.

It did work to some degree.

Makes me wonder about some of the claims made by writeups on the web where people are supposedly using twin cantennas and the like to get around objects.

On 16 Jul 2011 08:56:44 +1000, "Dr Who"
<dead_letter_office@hotmail.com> wrote:


>This one refers to wifi application.
>http://www.jpier.org/PIER/pier104/15.10032003.pdf

Metalized foam antennas is a great way to do many things. I've built
several patch antenna prototypes out of foam and foil. I also have
several Larkin patch antenna prototypes for 900MHz built onto foam.
I've also thrown together a rather odd antenna made from polyurethane
foam board with aluminum foil on both sides. Not the best for RF, but
very cheap and easy to find. However, these are large bulky antennas
and not intended for miniaturized applications, such as with Fractals.

>Incidentally in regard to my original posting about the stick on
>"booster", it got me thinking about passive repeaters and I tried
>hooking two directional antennas together to see how they would work
>as a passive repeater (54G and 1 metre cable length).
>
>I was interested to see what sort of losses could be expected.

Plenty of losses. I did the numbers for a passive repeater a few
years ago in this snoozegroup. Digging...
<http://groups.google.com/group/alt.internet.wireless/msg/cccf3ec82bc12edc>
I've found situations, where a passive repeater is actually useful,
but those invariably are fixed locations, with high gain antennas,
and with no RF leaking around the passive repeater.

>Basically I had a biquad outside of my brick garage with large
>metal door (no signal inside) garage and a 60 degree patch antenna
>inside, accessed by my laptop.
>
>The signal from the house was about 65 dBm.
>
>It did allow the signal to be accessed in the garage at low strength
>and speed (max of 11 Mbyte/sec).
>
>The setup looked to be pretty inefficient.
>
>It did work to some degree.

Yep. That's the problem. With no direct signal, it brings up the
signal levels to a lousy weak and useless signal. Not exactly my idea
of an improvement but sometimes better than zero signal. See my calcs
above for a clue.

>Makes me wonder about some of the claims made by writeups on the web
>where people are supposedly using twin cantennas and the like to
>get around objects.

Hint: No numbers, no value to the claims.

On the other foot, I'll be selling my Wi-Fi wave magnet. Hang it
around your antenna, router, or laptop and it uses the unused magnetic
part of the E-M wave to attact signals. It won't do anything for
transmit, but it will "bring in" all kinds of signals you have never
heard before.
<http://www.suertenich.com/html/radios/antenna.html>
I'll also be selling Orgonite jewels suitable for "gifting" which
detoxifies the atmosphere around the radio thus decreasing its BER
(bit error rate).
<http://www.orgonite.info/what-is-orgonite.html>
<http://www.orgonite.info/how-to-make-orgonite-tbs.html>

Patents pending by SOMA (Snake Oil Magnetic Associates).

--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831-336-2558
# http://802.11junk.com jeffl@cruzio.com
# http://www.LearnByDestroying.com AE6KS

Meanwhile, at the alt.internet.wireless Job Justification Hearings, Jeff
Liebermann chose the tried and tested strategy of:

> Drivel: An old rule-of-thumb in antenna design is that the uglier the
> antenna, the better it works I've often suspected that fractal
> antennas are proof of this rule.

Some, including me, find fractal patterns to be quite beautiful, although I
can imagine others not being so bothered.

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