On 16 Jul 2011 08:56:44 +1000, "Dr Who"
>This one refers to wifi application.
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...
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
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).
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# http://802.11junk.com firstname.lastname@example.org