George Hardesty

Jul 152009
 

[The following was compiled by a Data Alliance customer who approved of the posting of his writings here]:

DOWNLOAD DRIVERS FOR Realtek 8187L chipset (the chipset of the Alfa AWUS036H 1000mW USB adapter):

http://www.realtek.com.tw/downloads/downloadsView.aspx?Langid=1&PNid=1&PFid=1&Level=6&Conn=5&DownTypeID=3&GetDown=false&Downloads=true#RTL8187L

New drivers (dated 11/16-20) for the Alfa Networks (e.g. Realtek 8187L chipset) USB device have been posted on Realtek’s site (v1293) .

====
Download page for the older version Realtek 8185L chipset:http://www.realtek.com.tw/downloads/downloadsView.aspx?Langid=1&PNid=24&PFid=1&Level=6&Conn=5&DownTypeID=3&GetDown=false&Downloads=true

THE REMAINDER OF THIS POST MAY BE OUTDATED:

The new driver works very well with WinXP (at long last)…I am still using my tweaks (14 in Long and Short Retry Limits), and I am not using the associated client software ( I am still using XP’s “zero configuration utility” – “Use Windows to configure my wireless network settings” box checked)

Throughput has improved – especially in “burst” mode – and the “Site Survey” bug is fixed (thus far has not re-appeared). That bug required the adapter to “restarted” in order to have it find anything sometimes. It seems to be forming connections much quicker as well..

All-in-all – a big improvement over other recent versions – Although the 1207 version is just as stable…It appears that the many bugs which were introduced along the way to the Vista “port” of the driver have been fixed.

These comments are with respect to WinXP – No other OS was tested.

Be sure that you reference/download the 8187L driver and not the others.

Clearly Realtek has been doing quite a bit of work …From 1243 to now has been a real nightmare…or maybe a “Realtek” nightmare would be more accurate.  I think they only have one guy as a developer for the chip.  Fortunately the Vista stuff has caused him to look more carefully at a bunch of the other code.  A review of the comments tells you how serious the problems have been….disconnects, power-management…etc..

There have been quite a few corrections since the 1207 version…And it is clear that recent versions introduced as many bugs as they fixed.

Realtek does not keep older versions around, so it’s always good to stay on top of new versions.

 Posted by at 10:01 am Alfa AWUS036H No Responses »
Jul 152009
 

It’s difficult to give accurate estimates of range and signal strength, because every situation is different.  

As an example of the difficulty of estimating range:  In situations in which a lot of radio-frequency equipment is in use (such as hospitals, law enforcement, fire station), this RF gear will interfere with WiFi signals and reduce range.

Of course, obstacles of any kind will reduce range, and direct line of sight is the best situation to produce the longest range.   Obstacles adjacent to the line of sight will affect range, though less than obstacles in the line of sight.

Roofs, such as on a porch, pavilian, purgula etc. will also reduce range/signal strength even when you have a direct line of sight.  If you step out from under the roof or pavilian, you will probably see an increase in signal strength.

Jul 152009
 

 Alfa 1000mW client works on Fedora 7 Linux:

You have to add the line “alias wlan0 rtl8187” to the file /etc/modprobe.conf Then reboot. after booting into the GUI go to System | Administration | Network. New – Wireless – Follow it through.
====

Alfa compatible profile manager / site survey wizard for linux – Fedora 7.

Open a terminal and type in “yum install wlassistant”

this will then show up under system | preferences as Wireless Assistant.
=====

This information provided by:  Brendon Prole

Jul 152009
 

 We’re over the moon that we can get one of your Alfas to work over such a wopping distance. If you’d like us to say anything or about any of the other products we have bought from you please let us know.

Sylvan Andrew  Oct. ’07

===

The 500mw Alfa card with the optional 9 dbi antenna brings in excellent internet connectivity to my sailboat.

Within the next couple of days, will take my laptop and Alfa card (with both the standard and the optional 9 dbi antenna) and see if I can pick up the internet from the furthest points in the Marina.

Roger Freedman – October ’07

Jul 152009
 

Based on what I’ve been told by an expert in the Realtek chipsets:

Realtek chipsets are the best in terms of compatibility with both Mac and Linux.

I’m not a Mac user and so I don’t have any first-hand experience or knowledge about how to configure.  But I think that your best bet is to download drivers from the realtek website.

Will very much appreciate if Mac users will post comments about their experiences with the Alfa AWUS036H.

Alfa AWUS036H has a realtek chipset.

 Posted by at 9:47 am Mac compatibility Tagged with:  No Responses »
Jul 152009
 

NOTE: Alfa AWUS036 is the lower-power version – NOT the ALFA 500mW USB ADAPTER (that item is part# AWUS036H)

In order to get the “Alfa awus036” adapter working on an intel mac mini, osx 10.4, i had to download the drivers from the Ralink site. The included drivers on the cd were only for Windows and the native apple drivers did not work. Also, turn off Airport.   It works perfect now, as the other item i bought. Thanks for the great deals.

Chris Norris

The link to the drivers is:  http://www.ralinktech.com/ralink/Home/Support/Macintosh.html

 Posted by at 9:43 am Mac compatibility Tagged with:  No Responses »
Jul 152009
 

Alfa 1000mW USB adapter in the past (2006 to 2008) came with a USB Y cable (that has two connectors):

The dual lead USB cables were included in the past only to provide electric power for old laptops from the 1990s.  The dual USB cable had nothing to do with Tx/Rx output.

Old laptops/notebooks from the 1990s do not support full USB power such as 3.3V 1A.  New notebooks have full support so, it’s no problem to use only one USB connectors on the cable (if using the Y-type USB cable, you can use only the larger of the two USB plugs).

If your notebook is old:  If you want full output power, better to use 2 USB connector.

Jul 152009
 

Another great sure-fire tip from customer/Alfa user Trey MacDonald, in his words:

“…I found will significantly improve the “perceived” performance on the part of the Alfa Network USB client.

For starters, I’m assuming that for the most part, customers who purchase this unit are trying to achieve longer distance connections, etc,..”in the neighborhood” (wink, wink)….

One problem with this, is that most people leave their wireless hubs, set to the default..Let’s say, “linksys” on channel 6… Consequently buying a directional antenna is essential to sorting out the signals.

Nevertheless, even when you get a connection, the other signals can “bleed in” and disrupt the traffic.

Obviously, there are parameters which can be modified, with respect to packet-size, and fragmentation threshold, etc. – in conjunction with a good “ping” tool such as:

http://www.colasoft.com/ping_tool/

Which will allow someone to adjust packet sizes, frequency, and TTL….

BUT – this requires some competency and understanding – Which may be above the comprehension of the average user..

Here’s the tip.Once installed, go to the Control Panels/Network Connections
Right-click on the USB Network Adapter and Select Properties
Click on the Configure button on the right-hand top, of the General tab

Go to the Advanced tab
Set the value of “Long Retry Count” to a higher value – The default is 7, (I used 21)
Set the value of “Short Retry Count” to a higher value – The default is 7, (I used 21)

Click OK.

That’s it !

The effect of making this change, is that the adapter will retry the packets (both long and short) many more times AT THE DRIVER LEVEL before reporting an error. In many cases this will overcome poor reception or disruptive interference.

The consequence to the end-user is that the connection appears to be more reliable, because the driver is doing all of the work of repeating packets…

This solution is significantly less complicated than actually tuning the connection – but it has the desired effect. I think in the circumstances I described, quite profound.

The reason for this, is for the most part, web-based protocols like HTTP – use what’s called “AT LEAST ONCE” semantics – which means they automatically discard duplicate packets – therefore the effect of re-transmitting is non-consequential…and is much preferred to the driver reporting back to the browser that the connection itself has “stalled” …or to the OS that the connection has been dropped. The idea is to perform the re-transmit at the lowest overhead point – at the driver.

-Trey MacDonald

Copyright © 2004 - 2017 Data Alliance lnc. All Rights Reserved