Thanks for the reply! On Tue, 13 Jun 2006, Stuart Henderson wrote:
> I think CR31 just maps over the whole range of the card, > so for a card with a more powerful amp, a particular CR31 setting > relates to higher power output than it would on an ordinary card. Yes, that is what I figured too from the source. I have a 200mW card here which I'd like to limit to 100mW (european limit) by setting the appropriate txpower after accounting for antenna gain/cable loss. However, I doubt that e.g. subtracting 3dBm is sufficient, say "ifconfig wi0 txpower 17" won't give me the desired 100mW because the mapping is unlikely that linear or is it? The correct mapping is probably known only to the card manufacturer/ firmware vendor (for the curious: Senao NL-2511CD PLUS EXT2). While I'm at it an OT(?) question: Does somebody know how to _simply_ (using a multimeter or an old 20MHz scope) measure the power output of a wireless NIC? Just a rough (+-10mW) estimate would suffice. The antennae are external so I have access to the SMA. Then I could measure the mapping myself. > With some cards setting CR31 too high can give a distorted signal > and increase out-of-channel radiation (some references if you google > for WAP11 CR31 e.g. http://www.maokhian.com/wireless/wap11.html) Thanks for the reference. I'm trying to lower txpower to a _certain_ level, though. Google will find ways to increase power but I'm interested in the actual txpower value. So I wondered if ifconfig displays txpower correctly. As it turned out, not for cards != 100mW. Regards, Walter
