Any comments on the effectiveness of one of these boosters?

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

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.

extensive real world and lab test of similar devices then billed as 'passive repeaters'.

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.

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Know about fractals but not about fractal antennas,

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

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extensive real world and lab test of similar devices then billed as 'passive repeaters'.

fractal antennas (HD TV application) and they are pretty impressive considering their size.

seemed unlikely but had to ask.

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

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.

Gain, size, bandwidth. Pick any two.

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.

I blundered into this Koch fractal antenna analysis.

More:

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.

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.

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.

Plenty of losses. I did the numbers for a passive repeater a few years ago in this snoozegroup. Digging...

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.

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.

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.

I'll also be selling Orgonite jewels suitable for "gifting" which detoxifies the atmosphere around the radio thus decreasing its BER (bit error rate).

Patents pending by SOMA (Snake Oil Magnetic Associates).

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

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