And...several models don't work best at the default setting.
Examples:
Asus WL-520GU runs better at 20-40mW
Buffalo HP-G54 shouldn't be taken above 36mW due to the pre-amp.
Do you know where there's more information about this? It's out of the blue to me. Considering that the default has been 71 for what seems like years now, one has to wonder.
The information redhawk provided stands from extensive testing by himself and information gathered from moderation of this forum. _________________ Eko Builds
Yes, but by "more information" I meant things like details, ramifications, etc. I've been around here a pretty good bit, and this information is so under the radar that it's essentially invisible. People need to understand the import of running at the default, since almost everyone is.
Yes, but by "more information" I meant things like details, ramifications, etc. I've been around here a pretty good bit, and this information is so under the radar that it's essentially invisible. People need to understand the import of running at the default, since almost everyone is.
Without getting too technical (transistor theory, Smith charts, etc.) here's what I can say.
It's like the sound of a car stereo turned way up. At some point it just sounds like $#!@ and the enjoyment may even decrease.
As you turn up the TX power knob, at some point, the "usable power" (undistorted power) coming out of the antenna stops rising at the same rate as the number on the knob. As you turn the power up further, the usable power can even start to decrease, and/or the "unusable power" i.e. distortion can interfere with the reception of the usable power, such that the net effect is a decrease in the connection speed.
Somewhere in another thread, I posted a method like: keep dropping the TX power by 20-30% till you find where the connection speed goes down, then turn it up by a smaller increment till any further increase in power has no effect on speed. Obviously, simply increasing power beyond that point won't do anything good. Also, if you change your antenna, you'll have to redo the experiment, as it depends on the characteristics of the RF amp and antenna as well as their interaction as a system.
For example, I found that the default of 71 was way too high for my star network of Asus 500gPv2 and 520gU routers with 5dBi omni external antennas. Turning TX down allowed me to get the full 54 Mbps through concrete walls, around corners etc.
@modervador, OK, that's helpful. So performance and well-being of the router (per the original post) are at play here. This sounds important. Perhaps a list of guidelines for various models, beyond what's in this thread, should be in the Peacock thread or the wiki. Maybe there's already a thread dedicated to this, but finding it on this board is difficult when you can't restrict searches to Subject text only.
Following with that audio analogy but getting slightly more technical, when you turn power up too high the signal starts getting clipped. This is true for all kinds of signals. Your hardware is only capable of producing a finite amount of power output and if you try to go too high, then you start clipping the signal which makes the tops/bottoms of the waves flattened, ie. the signal gets distorted. _________________ Read the forum announcements thoroughly! Be cautious if you're inexperienced.
Available for paid consulting. (Don't PM about complicated setups otherwise)
Looking for bricks and spare routers to expand my collection. (not interested in G spec models)
that's not all. the transmitter and the receiver share the antennas. the transmitter uses resonance circuits, which continue to radiate for a short while after the transmitter has stopped tranmitting, just like a guitar does not stop making sound after you have released the string. at higher tx levels this decay takes longer, so possibly 'deafening' the receiver, which in turn might miss some sync bits.
if you need more coverage, mount a better antenna. in this way as well the transmitter as the receiver benefits. _________________ now running tomato by shibby
E4200v1 cfe 2010.09.20.0
interesting discussion on signal power, may i ask what's the measurable and practical outcome of varying TX power? Something like inssider could measure the dBm, would that be a direct indicator of the appropriate TX level, or is something else more appropriate? I'd just like to have something that's more precise than "blind" experimentation with download speed.
As I and others have said repeatedly in various ways.
Quote:
interesting discussion on signal power, may i ask what's the measurable and practical outcome of varying TX power? Something like inssider could measure the dBm, would that be a direct indicator of the appropriate TX level, or is something else more appropriate? I'd just like to have something that's more precise than "blind" experimentation with download speed.
Rough measures of received signal quality are available on the DD-WRT status page and on most non-DD-WRT wireless client adapter software. The measurable and practical outcome of varying TX power is that the throughput may change. Since moving bytes is the important function of the device, directly measuring effects on that function itself is by no means blind or imprecise. Hey, I just found that "Somewhere in another thread" post I cited above several days ago: http://www.dd-wrt.com/phpBB2/viewtopic.php?p=373187#373187
This is indeed interesting discussion but are we getting somewhat afield of a "Great DD-WRT misconceptions" issue? The point already made and seconded was that "pumping up the TX power to it's maximum level, can makes things worse and even destroy the router over time." If folks want to discuss the nitty-gritty of TX power further, should we take it to a different thread?
