[From nobody Sat Aug 16 21:13:45 2008 Return-Path: <support-bounces@lists.openmoko.org> Received: from mail.openmoko.org ([unix socket]) by mail.openmoko.org (Cyrus v2.1.18-IPv6-Debian-2.1.18-5.1) with LMTP; Tue, 05 Aug 2008 16:20:38 +0000 X-Sieve: CMU Sieve 2.2 Return-path: <support-bounces@lists.openmoko.org> Received: from sita.openmoko.org ([88.198.124.203]) by mail.openmoko.org with esmtps (TLS-1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.63) (envelope-from <support-bounces@lists.openmoko.org>) id 1KQPH4-0005jY-Gm; Tue, 05 Aug 2008 16:20:38 +0000 Received: from localhost ([127.0.0.1] helo=sita.openmoko.org) by sita.openmoko.org with esmtp (Exim 4.63) (envelope-from <support-bounces@lists.openmoko.org>) id 1KQPGg-0005hm-Cf; Tue, 05 Aug 2008 18:20:14 +0200 Received: from mail.openmoko.org ([88.198.124.205]) by sita.openmoko.org with esmtp (Exim 4.63) (envelope-from <joerg@openmoko.org>) id 1KQPGV-0005gk-QD; Tue, 05 Aug 2008 18:20:12 +0200 Received: from 118-166-66-221.dynamic.hinet.net ([118.166.66.221] helo=halley) by mail.openmoko.org with esmtpsa (TLS-1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.63) (envelope-from <joerg@openmoko.org>) id 1KQPGS-0005dV-Lt; Tue, 05 Aug 2008 16:20:03 +0000 From: Joerg Reisenweber <joerg@openmoko.org> To: Andy Green <andy@openmoko.com> Date: Wed, 6 Aug 2008 00:16:59 +0800 User-Agent: KMail/1.9.6 (enterprise 20070904.708012) References: <20080805140611.GC3421@telvanni.starfleet> <200808052129.22147.joerg@openmoko.org> <489857C6.9020208@openmoko.com> In-Reply-To: <489857C6.9020208@openmoko.com> MIME-Version: 1.0 Message-Id: <200808060017.04855.joerg@openmoko.org> X-Spam-Checker-Version: SpamAssassin 3.1.7-deb (2006-10-05) on sita.openmoko.org X-Spam-Level: X-Spam-Status: No, score=-4.4 required=5.0 tests=ALL_TRUSTED,BAYES_00 autolearn=ham version=3.1.7-deb Subject: Re: Buzzing sound Cc: support@lists.openmoko.org X-BeenThere: support@lists.openmoko.org X-Mailman-Version: 2.1.9 Precedence: list Reply-To: Support for Openmoko Device Owners <support@lists.openmoko.org> List-Id: Support for Openmoko Device Owners <support.lists.openmoko.org> List-Unsubscribe: <https://lists.openmoko.org/mailman/listinfo/support>, <mailto:support-request@lists.openmoko.org?subject=unsubscribe> List-Archive: <http://lists.openmoko.org/pipermail/support> List-Post: <mailto:support@lists.openmoko.org> List-Help: <mailto:support-request@lists.openmoko.org?subject=help> List-Subscribe: <https://lists.openmoko.org/mailman/listinfo/support>, <mailto:support-request@lists.openmoko.org?subject=subscribe> Content-Type: multipart/mixed; boundary="===============1736991325==" Mime-version: 1.0 Sender: support-bounces@lists.openmoko.org Errors-To: support-bounces@lists.openmoko.org X-UID: 18521 X-Length: 5925 --===============1736991325== Content-Type: multipart/signed; boundary="nextPart2981598.POcmhmK8gU"; protocol="application/pgp-signature"; micalg=pgp-sha1 Content-Transfer-Encoding: 7bit --nextPart2981598.POcmhmK8gU Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Am Di 5. August 2008 schrieb Andy Green: > Somebody in the thread at some point said: >=20 > |> So it comes and goes in discrete steps and it lags behind the change of > |> position. > | > | That's exactly the behaviour we would expect when noise is related to > | MS-TXPower controlled by a PCL command from BS. BS isn't responding to > any > | momentary change in signal-strength of inbound MS-signal, instead BS do= es >=20 > Sounds good. >=20 > Just a note, on the "skelephone" that I use I replaced the GSM antenna > with a short length of patch wire, it still works (and some guy was > complaining normal GTA02 is for hardcore hackers). I guess if I > shortened it further, it can force base station to tell me to use max > power all the time. RF performance seems fine with $WIRE like 5cm long. When shorting the wire, we reduce antenna gain. This basically means we nee= d=20 more power from battery, to have the same RF signal strength. So yes,=20 probably BS would level up the PCF, but only to the point where we have sam= e=20 local RF field around GTA02. As noise is supposed to be introduced to GTA02= =20 by own (and externally applied) RF, and not by battery current LF/DC, the=20 only effect would be a reduced battery life time.=20 In fact it's the SWR [http://en.wikipedia.org/wiki/Standing_wave_ratio] tha= t=20 gets worse when creating a impedance missmatch by shortening antenna, so a= =20 part of the RF-power is reflected at antenna rot point and fed back to=20 amplifier and dissipated producing heat. Depending on power and design of=20 last amplifier stage this can even burn out the amplifier. Of course reducing the antenna gain is a little bit like flashing another=20 power class to the firmware, in that it limits the maximum effective RF pow= er=20 the device can emit. So maybe this could be one of the possible fixes for=20 this issue (a very nasty one, that probably even won't yield the desired=20 results) to reduce gain by crippling the built-in antenna. cheers jOERG --nextPart2981598.POcmhmK8gU Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part. -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.4-svn0 (GNU/Linux) iD8DBQBImH0A7Xtwhpk1UgwRAg+lAJ9oR1Xa65eqErBW1++A6mD1PSGZIgCeLySo M9z+O49gn8jTz3PIcSYmjFc= =o398 -----END PGP SIGNATURE----- --nextPart2981598.POcmhmK8gU-- --===============1736991325== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ support mailing list support@lists.openmoko.org https://lists.openmoko.org/mailman/listinfo/support --===============1736991325==-- ]