How Stable is your Signal?

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strapabiro
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PostPosted: Wed Jul 01, 2009 9:23    Post subject: Reply with quote
Dude, chill, long life is rare ... i know everyone can do what he wants, don't need bold colored text to prove your free will (And definitely not PM lol?). I was asking some logical explanation like ... components will be owerpowered and will fry in time or something like that ... I rather ask before i blow something up. Whatever. Have a nice day.
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Radioman193
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PostPosted: Wed Jul 01, 2009 9:37    Post subject: Reply with quote
Im am Cool Cool
you?
just wanted to give you some info.
"owerpowered and will fry in time or something like that ... I rather ask before i blow something up"
ok...These are Just a >few Examples<
http://www.dd-wrt.com/phpBB2/viewtopic.php?t=53296&start=150

if you look at the PDF's the "components" can do alot more and still within Spec.
Asking is one thing but How you Ask is another.


Cool

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Radioman193
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PostPosted: Wed Jul 01, 2009 10:01    Post subject: Reply with quote
Recap: Antenna
Fact:
Preformance depends on the "antenna efficiency" and the antenna and that is in use and the VSWR of the Antenna and the Receiver sensitivity.

if you got a antenna with Good efficiency and a Good SWR a 3% increase in power you will see a inprovement. in (ERP).
it looks like this
************* Example ****************************
Actual Transmitter Power Output = 0.03 dbw
Antenna Gain = 7 dbi
will give you
Effective Radiated Power (ERP)
4.8815615195230215dbw = 3.0772Watts
Or rounded we got
4.882dbw = 3.077Watts
now we got
Effective Isotropic Radiated Power (EIRP)
7.03dbw = 5.04661Watts
Round that off to
7.030dbw = 5.047Watts

all that to say if you got a 7dbi antenna with a SWR of 1.1 to 1
with 0.03 dbw in your Effective Out put will be 5.047 Watts out.


this might help somebody
http://www.radiolabs.com/stations/wifi_calc.html
and or
http://www.csgnetwork.com/antennaecalc.html

Enjoy learning
Cool

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Last edited by Radioman193 on Wed Jul 01, 2009 10:24; edited 1 time in total
Radioman193
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PostPosted: Wed Jul 01, 2009 10:10    Post subject: Reply with quote
I have 3 7dbi antennas on it now with a SWR of 1.3 to 1 for a Effective ERIP of 6.3 watt
http://www.dd-wrt.com/phpBB2/files/dcfc0024_116.jpg

soon to put 3 16dbi antennas on it
That would be "if the SWR is Low" Effective ERIP of 50 watt!
Omni the Only way to go!

Cool

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Radioman193
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PostPosted: Wed Jul 01, 2009 10:23    Post subject: Reply with quote
Recap:Linksys Power supply
I dont know why but linksys looks like thay like Starving ther Wireless Routers and Ap's of POWER.
thay supply you with a 1 to 1.5 amp "Wallwart" Powersupply way under what you need .
just look a the Product spec sheet lets say just for a wpc300n PCMCIA WiFi card.
JUST the Card.
Power Consumption
TX: <900mA (Maximum)
RX: <700mA (Maximum)
http://downloads.linksysbycisco.com/downloads/WPC300N_ds,0.pdf


Now we need to look at what the BCM4705 CPU Power Consumption is 5v @ 2.4w = 0.48 amp just under 1/2 amp.
http://www.broadcom.com/collateral/pb/4705-PB01-R.pdf


The Switch BCM 5325 Power Consumption is 5v 1.4W = 0.27999999999999997 amp
http://www.broadcom.com/collateral/pb/5325-PB05-R.pdf

and the Ram Power Consumption is well im not shure what the ram power Consumption is .

Plus Remember the +/- % that is NEEDED Normaly 5% to 10%
And you shuld have a power supply that has a power rating of At least 5% Over what you need to keep things cool.

Cool

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Radioman193
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PostPosted: Wed Jul 01, 2009 10:27    Post subject: Reply with quote
Recap:
Antenna diversity
:

if you have 2 Antennas
Don't Use auto for Tx and Rx antenna use 1 for Rx and 1 for Tx .
Why?
1 well when its in "Auto" mode you will have switching noise .

2 and Timeing between antennas Rx ant Tx
think of it like this if it is set to "auto".
If antenna 1 is in Rx and #2 is in Tx when thay switch you have one point in time when you Dont have a Rx antenna Or a Tx antenna or you will have 2 Tx antennas or 2 Rx antennas .
yes i know the time is VERRY short like in Micro Seconnds but it is a fact.

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greekstile
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PostPosted: Wed Jul 01, 2009 16:24    Post subject: Reply with quote
Radioman193 wrote:
strapabiro wrote:
I saw some other members stating that the factory wall wart (1A) is weak for thiese routers and they are using 5A ones.
Ok let's say it's true but from 1A to 5A? Isn't that a bit high?

5amp works for me.
Cool


Either way, just because a power supply is rated at 5A, doesn't mean it's blindly feeding that much juice to the router. It simply means that it's capable of supplying that much, should the router need it.

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hardwarewizard
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PostPosted: Wed Jul 01, 2009 16:49    Post subject: Reply with quote
Radioman do you have a way to measure the current on the new supply to see what the actual draw is??




FYI (to those that don't know): just cause it says it will do 5 Amps it does not mean the unit is drawing it it will only take what it wants.


Also on my wrt54g v3 its been running 251mw for at least 4 years 24/7 and not a single problem. i think the secret is just keep good air flow around the unit.
Radioman193
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PostPosted: Wed Jul 01, 2009 17:22    Post subject: Reply with quote
Thats right a switching power supply will only deliver what the load needs upto the power supplys max and go into protect and the output will be cut off. Cool
.................................................

Yes I can and Have
2.68 Amp not in use just powered on .
>Your results may vary<
your current load will go up ?% under Cpu load and switch load.
I have not tested Max current draw . 5anp for the power supply was a logical conclusion
takeing in to consideration the + - 5 to 10% you shuld have Over the needed Max current draw .
Cool

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Radioman193
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PostPosted: Wed Jul 01, 2009 17:32    Post subject: Reply with quote
And Remember even at MAX output
the hottest Item in your router is the Switch.
Always Use Heatsinks
I Do and With Articsilver.
Cool

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Last edited by Radioman193 on Wed Jul 01, 2009 20:38; edited 1 time in total
greekstile
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PostPosted: Wed Jul 01, 2009 18:31    Post subject: Reply with quote
Here is a good little blurb from 12vadapters.com:

The only information you need to have in order to find the correct power supply for your device is the Voltage / Volts (V) and Amperage / Amps (A).

Voltage has to be an exact match. A 12V DC device needs a 12V DC adapter.

Amperage is the amount of power your device uses. The adapter you order has to be able to supply AT LEAST the amount of Amps your device draws. If your device states it is 12V 3A, a 3A adapter can handle that load, but so can a 4A and 5A. The higher amperage (amp) power supply will not have to work as hard to handle a smaller load, and will run cooler and more stable.


Common sense, but there you have it.

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Murrkf
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PostPosted: Wed Jul 01, 2009 19:07    Post subject: Reply with quote
greekstile wrote:
Common sense, but there you have it.


But, what if the device IS capable of drawing more, but in the process will also create more heat? Could the engineers be using the limitation in the AC adapter as a method of keeping the heat issues minimized? Obviously if there isn't enough power available to cause overheating, overheating can't be a problem.

I *think* what is being said here is that the router is capable of drawing more power, and will perform better if there is more power available, and to get amplification/greater dbi there NEEDS to be more power, but that this will also create more heat that needs to be properly dealt with and that hasn't necessarily been engineered for.

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greekstile
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PostPosted: Wed Jul 01, 2009 19:39    Post subject: Reply with quote
Murrkf wrote:
greekstile wrote:
Common sense, but there you have it.


But, what if the device IS capable of drawing more, but in the process will also create more heat? Could the engineers be using the limitation in the AC adapter as a method of keeping the heat issues minimized? Obviously if there isn't enough power available to cause overheating, overheating can't be a problem.

I *think* what is being said here is that the router is capable of drawing more power, and will perform better if there is more power available, and to get amplification/greater dbi there NEEDS to be more power, but that this will also create more heat that needs to be properly dealt with and that hasn't necessarily been engineered for.


Common sense, but there you have it.

;)

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barryware
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PostPosted: Wed Jul 01, 2009 20:10    Post subject: Reply with quote
My 2 cents (I am almost out of cents Razz )

You never know but I would think that engineering a device by limiting it's power supply (available current) would be a 1/2 a$$ed way of doing it. Again you never know but I don't think that is what the engineers had in mind.

The PS's could be a bit undersized as a cost cutting method. Just big enough but no "head room" available.

If your audio amp does not have the balls to drive your speakers... what happens? You get clipping & distortion, no "punch", etc. Not exactly the same as powering a router but a pretty close analogy.

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Radioman193
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PostPosted: Wed Jul 01, 2009 20:17    Post subject: Reply with quote
You got it .
Cool
the router will run on 500Ma but will SUCK.

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