Jeff Liebermann <(E-Mail Removed)> wrote in
news:(E-Mail Removed):
> On Sat, 7 Aug 2010 18:44:01 +0000 (UTC), dakid
<(E-Mail Removed)>
> wrote:
>
> Hint: What problem are you trying to solve and what do you
have to
> work with? You'll get better answers if you supply this
information.
Thanks for your reply. Sorry I am not able to converse with
you at your level on this topic.
So far in my area I have found 3-5 APs, no encryption using
open routers, no pw. I am sure there are more. I just want to
surf the net and chat, primarily. Over months some disappear
and then new ones appear. I guess they are starting to wise
up that its not a good idea to run unencrypted APs with open
routers. Or maybe they are just leaving it open for whoever.
>
>>I am using a 1' by 1' homemade parabolic
>>reflector behind a 5 inch whip-manila folder with pasted
alum
>>foil glued to parabolic foam shapes made from a parabolic
>>template. What do you think the probabilities are that the
>>Hawkins will give a
>>significant improvement over that?
>
> 100%. Your antenna is probably not properly matched to 50
ohms. Your
> aluminum foil feed probably does not properly illuminate
the dish,
> resulting in "over-spray" with radically different gains on
receive
> and xmit. In short, without test equipment, a decent
design, and
> careful construction, your home made contrivance is
unlikely to
> provide a major improvement in antenna gain.
The parabola was cut from a template that supposedly is an
efficient half parabola with the rubber whip at the focal
point or as near as homemade can make it. So why the
"overspray", not sure what you mean by "illuminate the dish".
The antenna is designed to focus the reflections off the
parabola to the whip, and was intended for use with a whip.
Obviously I don't know half of what you're talking about,
sorry. Of course this is not factory made so I am sure that I
am not reaching the dimensions and curves as closely as with
factory built. As far as the 50ohm impedance, I guess can I
add a resistor to generate that, and where?
>
> That being said, I'm always amazed at how crudely an
antenna can be
> build and still work. That applies to antennas with gains
of less
> than about 8dBi, such as coffee cans and simple reflectors.
Over
> about 8dBi gain, things start to get critical and narrow
band.
>
>>The signal strength from
>>my adapter software says it is running about 80% but the
>>signal quality is only about 50-65%, and I am getting Rx
>>retrys about half of Rx Oks.
>
> Lots of retransmissions suggests interference. Try
different RF
> channels or run a site survey (scan of existing wireless
networks). If
> possible use a spectrum analyzer.
How can I change a channel for which I have no control over
the transmitter?
>
>>Actually these readings seem to
>>bear little relation to the speed of downloading pages.
>
> Got any numbers?
Only what I already gave you. The software supplied with the
usb radio does not help much in determining which antenna
position or even AP is providing the best throughput. For
examply I can get a signal quality of 40% and have better
throughput than when the bar reads 60%, or so it seems. Link
quality bar is not any help either.
>
>>Have
>>tried moving the antenna all around different positions and
>>different angles, am I am now getting the best I can get
with
>>this antenna. The 1' by 1' reflector is affixed to slots on
>>the top of a small cardboard box aimed towards my window. I
>>tried lining the bottom of the box and sides outside the
>>reflector with alum foil, but did not improve things. I
tried
>>shielding the adapter which is right below the antenna with
>>foil, also no improvement.
>
> I can't tell if the Hawking antenna is going to make any
improvement
> as you haven't disclosed how you're using the antenna and
radio. Are
> you trying to cover an area? Or are you trying to go point
to point?
> Big difference in recommended antenna types for each of
these. Also,
> indoors, outdoors, rooftop, folliage, through walls, etc.
>
>
> --
> Jeff Liebermann (E-Mail Removed)
> 150 Felker St #D http://www.LearnByDestroying.com
> Santa Cruz CA 95060 http://802.11junk.com
> Skype: JeffLiebermann AE6KS 831-336-2558
>
>
No I want an antenna that I can move around, directional that
will find all the available open APs around me. Indoors,
cannot do outdoors. Have no idea whats between me and the
APs, I am relying strictly on signal strength bars, link
quality bar and how fast pages load and testing throughput
with online test sites. I think a true dish antenna will be
too difficult to aim, so something that is directional but
not too directional. Also, I have no idea how the Hawkins
works or what's inside it, I just know they are claiming
12dBi and thats probably much better than what I am getting
with my homemade job, IF their claims are not so much hot
air.
Sorry if I am not able to give you more than my ignorance in
this area (although I am learning) allows.
Linear Mode
