From karthikcena00 at gmail.com Wed Mar 3 05:48:51 2010 From: karthikcena00 at gmail.com (karthik kar) Date: Wed, 3 Mar 2010 11:18:51 +0530 Subject: [Ronja] ronja Message-ID: can anyone say where can i buy the ronja.....i need it urgently for my project.......... -------------- next part -------------- An HTML attachment was scrubbed... URL: http://pointless.net/pipermail/ronja/attachments/20100303/fb11ddc6/attachment.html From mohammadaj at gmail.com Sun Mar 28 04:04:52 2010 From: mohammadaj at gmail.com (mohamad al-jamal) Date: Sun, 28 Mar 2010 06:04:52 +0300 Subject: [Ronja] new receiver design Message-ID: <9061a4381003272004j61ac9eafyc007b36e9a621a6f@mail.gmail.com> Dear all I have been trying to modify the Ronja inferno receiver for the sake of better performance .. i have replaced the first stage ( transimpedance amplifier ) with a conventional configuration : an opamp with an RC feedback circuit .. instability is avoided by inserting a relatively high capacitor in the feedback circuit .. the bandwidth is ruined though , therefore the NE592 is used - just like in inferno - to compensate for the integrator effect of the TIA . i used a high bandwidth opamp from texas instruments (OPA657) . and used another PIN photodiode , a cheap one from vishay ( http://www.vishay.com/docs/81503/bp10nf.pdf) . the PIN is directly biased by a -12 supply . and every thing went just fine !! the signal was nice and clean . i'am still experimenting , but it seems promising . this image illustrates the new configuration . http://img265.imageshack.us/i/rxfirststage.jpg/ i have a couple of questions though : regarding R3 in the schematics , i thought that R3 should be as high as possible in order to avoid thermal noise ... is that true ? regarding the filtration practice of the supply connected to the PIN , is the configuration in the image sufficient ? any ideas are highly appreciated . -------------- next part -------------- An HTML attachment was scrubbed... URL: http://pointless.net/pipermail/ronja/attachments/20100328/5ba6f94a/attachment.html From aiu-fso at hotmail.com Mon Mar 29 21:28:59 2010 From: aiu-fso at hotmail.com (FSO AIU) Date: Mon, 29 Mar 2010 20:28:59 +0000 Subject: [Ronja] tetrapolis receiver Message-ID: can i implement the receiver on a PCB instead of a tin box like in the website? thank you _________________________________________________________________ Hotmail: Trusted email with Microsoft?s powerful SPAM protection. https://signup.live.com/signup.aspx?id=60969 -------------- next part -------------- An HTML attachment was scrubbed... URL: http://pointless.net/pipermail/ronja/attachments/20100329/fd86a86a/attachment.html From gullik.webjorn at corevalue.se Mon Mar 29 21:53:18 2010 From: gullik.webjorn at corevalue.se (Gullik =?ISO-8859-1?Q?Webj=F6rn?=) Date: Mon, 29 Mar 2010 22:53:18 +0200 Subject: [Ronja] new receiver design In-Reply-To: <9061a4381003272004j61ac9eafyc007b36e9a621a6f@mail.gmail.com> References: <9061a4381003272004j61ac9eafyc007b36e9a621a6f@mail.gmail.com> Message-ID: <1269895998.9782.18.camel@core-laptop> Hello Mohamad, It is interesting to see people working on implementing the design with more modern components. How is your design performing? Have you compared sensitivity vs. noise against the standard frontend? What bandwidth are you getting? As for R3 in your schematic, if forms a pole with the 100 nF, at below a khz, so the noise contribution from R3 should be minimal in the band of interest, Mhz, I believe. The BPV10 is a good one, OPA905 is also a useful PIN, and readily available. I think you should be *very* careful with filtration of supply voltages, after all you will be building a high bandwidth "straight receiver" so the risk of unwanted feedback is there all the time. Shielding will be required, you will be running 120 + dB gain in the entire chain. Good luck, Gullik On Sun, 2010-03-28 at 06:04 +0300, mohamad al-jamal wrote: > Dear all > > I have been trying to modify the Ronja inferno receiver for the sake > of better performance .. i have replaced the first stage > ( transimpedance amplifier ) with a conventional configuration : an > opamp with an RC feedback circuit .. instability is avoided by > inserting a relatively high capacitor in the feedback circuit .. the > bandwidth is ruined though , therefore the NE592 is used - just like > in inferno - to compensate for the integrator effect of the TIA . i > used a high bandwidth opamp from texas instruments (OPA657) . and used > another PIN photodiode , a cheap one from vishay > (http://www.vishay.com/docs/81503/bp10nf.pdf) . the PIN is directly > biased by a -12 supply . and every thing went just fine !! the signal > was nice and clean . i'am still experimenting , but it seems > promising . this image illustrates the new configuration . > http://img265.imageshack.us/i/rxfirststage.jpg/ > > i have a couple of questions though : > regarding R3 in the schematics , i thought that R3 should be as high > as possible in order to avoid thermal noise ... is that true ? > regarding the filtration practice of the supply connected to the PIN , > is the configuration in the image sufficient ? > > any ideas are highly appreciated . > > > > > _______________________________________________ > Ronja mailing list > Ronja at lists.pointless.net > http://pointless.net/mailman/listinfo/ronja From mohammadaj at gmail.com Tue Mar 30 00:03:39 2010 From: mohammadaj at gmail.com (mohamad al-jamal) Date: Tue, 30 Mar 2010 02:03:39 +0300 Subject: [Ronja] new receiver design In-Reply-To: <1269895998.9782.18.camel@core-laptop> References: <9061a4381003272004j61ac9eafyc007b36e9a621a6f@mail.gmail.com> <1269895998.9782.18.camel@core-laptop> Message-ID: <9061a4381003291603i2d2d6907q2a5a830ace56df14@mail.gmail.com> the design is performing very nicely ... distance without lenses was roughly 1.5m . i'am still experimenting though ... as for the sensitivity and noise , i intend to increase the feedback resistor to 400K or so , it will form a pole almost at the same point inferno does , but with better sensitivity and noise performance ( at least theoretically !!) .. the signal at the output of the TIA is a sawtooth with 450mV p-p ... i don't know how to measure the noise properly !! but without an optical signal,we get a random noise (without oscillations) with about 80mV p-p . the strange thing we found is that the smaller R3 is , the better the performance gets !! any explanation !?!? as for the B.W , we used a function generator as a signal source , and the we ranged the frequency from 1MHz up to 13MHz or so , and nothing went wrong .. On Mon, Mar 29, 2010 at 11:53 PM, Gullik Webj?rn < gullik.webjorn at corevalue.se> wrote: > Hello Mohamad, > > It is interesting to see people working on implementing the > design with more modern components. How is your design performing? > > Have you compared sensitivity vs. noise against the standard frontend? > > What bandwidth are you getting? > > As for R3 in your schematic, if forms a pole with the 100 nF, at below > a khz, so the noise contribution from R3 should be minimal in the band > of interest, Mhz, I believe. The BPV10 is a good one, OPA905 is also a > useful PIN, and readily available. > > I think you should be *very* careful with filtration of supply voltages, > after all you will be building a high bandwidth "straight receiver" so > the risk of unwanted feedback is there all the time. Shielding will be > required, you will be running 120 + dB gain in the entire chain. > > Good luck, > > Gullik > > > On Sun, 2010-03-28 at 06:04 +0300, mohamad al-jamal wrote: > > Dear all > > > > I have been trying to modify the Ronja inferno receiver for the sake > > of better performance .. i have replaced the first stage > > ( transimpedance amplifier ) with a conventional configuration : an > > opamp with an RC feedback circuit .. instability is avoided by > > inserting a relatively high capacitor in the feedback circuit .. the > > bandwidth is ruined though , therefore the NE592 is used - just like > > in inferno - to compensate for the integrator effect of the TIA . i > > used a high bandwidth opamp from texas instruments (OPA657) . and used > > another PIN photodiode , a cheap one from vishay > > (http://www.vishay.com/docs/81503/bp10nf.pdf) . the PIN is directly > > biased by a -12 supply . and every thing went just fine !! the signal > > was nice and clean . i'am still experimenting , but it seems > > promising . this image illustrates the new configuration . > > http://img265.imageshack.us/i/rxfirststage.jpg/ > > > > i have a couple of questions though : > > regarding R3 in the schematics , i thought that R3 should be as high > > as possible in order to avoid thermal noise ... is that true ? > > regarding the filtration practice of the supply connected to the PIN , > > is the configuration in the image sufficient ? > > > > any ideas are highly appreciated . > > > > > > > > > > _______________________________________________ > > Ronja mailing list > > Ronja at lists.pointless.net > > http://pointless.net/mailman/listinfo/ronja > > > > _______________________________________________ > Ronja mailing list > Ronja at lists.pointless.net > http://pointless.net/mailman/listinfo/ronja > -------------- next part -------------- An HTML attachment was scrubbed... URL: http://pointless.net/pipermail/ronja/attachments/20100330/e89f8196/attachment.html From ymktwo at yahoo.com Tue Mar 30 04:17:25 2010 From: ymktwo at yahoo.com (Ymktwo) Date: Mon, 29 Mar 2010 20:17:25 -0700 (PDT) Subject: [Ronja] (no subject) Message-ID: <65667.34285.qm@web52405.mail.re2.yahoo.com> Hi like to check if any one try before beaming from inside a glass window to another site? ? I would like to place the transmitter and RX in side the building . ? Wallace Yaw Cheers always!!! Stay Happy My friends! New Email names for you! Get the Email name you've always wanted on the new @ymail and @rocketmail. Hurry before someone else does! http://mail.promotions.yahoo.com/newdomains/sg/ -------------- next part -------------- An HTML attachment was scrubbed... URL: http://pointless.net/pipermail/ronja/attachments/20100329/6afb8d51/attachment.html From mohammadaj at gmail.com Tue Mar 30 04:42:25 2010 From: mohammadaj at gmail.com (mohamad al-jamal) Date: Tue, 30 Mar 2010 06:42:25 +0300 Subject: [Ronja] (no subject) In-Reply-To: <65667.34285.qm@web52405.mail.re2.yahoo.com> References: <65667.34285.qm@web52405.mail.re2.yahoo.com> Message-ID: <9061a4381003292042o6c41c996l7c26169b12cf48e@mail.gmail.com> it depends on the type of the glass . the glass would attenuate the signal depending on the transmittance of the material . but i think it would be a negligible effect , as most of the glass types have a transmittance of 90% in the red and near infrared bands . On Tue, Mar 30, 2010 at 6:17 AM, Ymktwo wrote: > Hi like to check if any one try before beaming from inside a glass window > to another site? > > I would like to place the transmitter and RX in side the building . > > > Wallace Yaw > > Cheers always!!! Stay Happy My friends! > > ------------------------------ > New Email names for you! > > Get the Email name you've always wanted on the new @ymail and @rocketmail. > Hurry before someone else does! > _______________________________________________ > Ronja mailing list > Ronja at lists.pointless.net > http://pointless.net/mailman/listinfo/ronja > > -------------- next part -------------- An HTML attachment was scrubbed... URL: http://pointless.net/pipermail/ronja/attachments/20100330/5d683415/attachment.html From ymktwo at yahoo.com Tue Mar 30 09:12:44 2010 From: ymktwo at yahoo.com (Ymktwo) Date: Tue, 30 Mar 2010 01:12:44 -0700 (PDT) Subject: [Ronja] (no subject) In-Reply-To: <9061a4381003292042o6c41c996l7c26169b12cf48e@mail.gmail.com> Message-ID: <518896.99459.qm@web52407.mail.re2.yahoo.com> Hi al-jamal ? Like to check does the effective range of the Ronja be affected ? Wallace Yaw Cheers always!!! Stay Happy My friends! --- On Tue, 30/3/10, mohamad al-jamal wrote: From: mohamad al-jamal Subject: Re: [Ronja] (no subject) To: "GPL free-space optical datalink" Date: Tuesday, 30 March, 2010, 11:42 AM it depends on the type of the glass .? the glass would attenuate the signal depending on the transmittance of the material . but i think it would be a negligible effect , as most of the glass types have a transmittance of 90% in the red and near infrared bands .?? On Tue, Mar 30, 2010 at 6:17 AM, Ymktwo wrote: Hi like to check if any one try before beaming from inside a glass window to another site? ? I would like to place the transmitter and RX in side the building . ? Wallace Yaw Cheers always!!! Stay Happy My friends! New Email names for you! Get the Email name you've always wanted on the new @ymail and @rocketmail. Hurry before someone else does! _______________________________________________ Ronja mailing list Ronja at lists.pointless.net http://pointless.net/mailman/listinfo/ronja -----Inline Attachment Follows----- _______________________________________________ Ronja mailing list Ronja at lists.pointless.net http://pointless.net/mailman/listinfo/ronja -------------- next part -------------- An HTML attachment was scrubbed... URL: http://pointless.net/pipermail/ronja/attachments/20100330/6b1dfdf9/attachment-0001.html From gullik.webjorn at corevalue.se Tue Mar 30 10:45:31 2010 From: gullik.webjorn at corevalue.se (Gullik =?ISO-8859-1?Q?Webj=F6rn?=) Date: Tue, 30 Mar 2010 11:45:31 +0200 Subject: [Ronja] new receiver design In-Reply-To: <9061a4381003291603i2d2d6907q2a5a830ace56df14@mail.gmail.com> References: <9061a4381003272004j61ac9eafyc007b36e9a621a6f@mail.gmail.com> <1269895998.9782.18.camel@core-laptop> <9061a4381003291603i2d2d6907q2a5a830ace56df14@mail.gmail.com> Message-ID: <1269942331.11390.9.camel@core-laptop> On Tue, 2010-03-30 at 02:03 +0300, mohamad al-jamal wrote: > the design is performing very nicely ... distance without lenses was > roughly 1.5m . i'am still experimenting though ... as for the > sensitivity and noise , i intend to increase the feedback resistor to > 400K or so , it will form a pole almost at the same point inferno > does , but with better sensitivity and noise performance ( at least > theoretically !!) .. the signal at the output of the TIA is a > sawtooth with 450mV p-p ... i don't know how to measure the noise > properly !! but without an optical signal,we get a random noise > (without oscillations) with about 80mV p-p . My simplistic view 450/80 = 15 dB. If you use a good oscilloscope, measure the signal, then increase gain and measure vertical "thickness" of the trace, this works best on a square wave. > the strange thing we found is that the smaller R3 is , the better the > performance gets !! any explanation !?!? as for the B.W , we used a > function generator as a signal source , and the we ranged the > frequency from 1MHz up to 13MHz or so , and nothing went wrong .. > Measure voltage drop across R3 on various signal conditions. Maybe you find you are saturating the pin, causing large voltage drop, decreasing bias on PIN, causing less gain. What about a small R3, cap to ground, small L (ind), cap to ground?? Since the other node, PIN cathode goes to OP input / feedback resistor, a low R3 will not increase risk of excessive current in PIN. Regards, Gullik