From twibright at hispeed.ch Sat Nov 1 13:41:33 2008 From: twibright at hispeed.ch (Karel Kulhavy) Date: Sat, 1 Nov 2008 14:41:33 +0100 Subject: [Ronja] Noise of inductors Message-ID: <6258501.1225546895182.JavaMail.root@viefep16> I want to put a working inductor (6.8uH on ferrite core) close to the input. I have read about Barkhausen noise: http://en.wikipedia.org/wiki/Barkhausen_noise Do you know if HF ferrite coils also affected by this? Is the ferrite specially engineered to minimize this amount of noise? How significant it is? Since coils had been used in radios I guess someone must already have hit this problem. Karel From asteri_x at freemail.hu Sun Nov 2 10:07:28 2008 From: asteri_x at freemail.hu (=?UTF-8?B?R3l1cmvDsyBNYXJ0aW4=?=) Date: Sun, 02 Nov 2008 11:07:28 +0100 Subject: [Ronja] high speed measuring with photodiode Message-ID: <490D7BE0.9050004@freemail.hu> hi folks! how do i measure high speed ramp up with photodiode? Is it enough to just bias the PD with voltage, and use a 50 Ohm load resistor? Are there any other usages that make PD-s faster? bye, Martin From twibright at hispeed.ch Sun Nov 2 10:21:59 2008 From: twibright at hispeed.ch (Karel Kulhavy) Date: Sun, 2 Nov 2008 11:21:59 +0100 Subject: [Ronja] high speed measuring with photodiode Message-ID: <26534015.1225621320550.JavaMail.root@viefep12> ---- "Gyurk? Martin" schrieb: > hi folks! > > how do i measure high speed ramp up with photodiode? > > Is it enough to just bias the PD with voltage, and use a 50 Ohm load > resistor? > Are there any other usages that make PD-s faster? Give the diode the maximum rated voltage. That will decrease the capacitance. But with 1.3pF (SFH203 @48V) and 50 Ohm you have 2.5GHz, but the diode has internal speed only 200 MHz according to the datasheet. You cannot make the carriers move faster inside. How fast do you need it and for what purpose? Karel From twibright at hispeed.ch Mon Nov 3 19:16:46 2008 From: twibright at hispeed.ch (Karel Kulhavy) Date: Mon, 3 Nov 2008 20:16:46 +0100 Subject: [Ronja] Measuring capacitance of inductors with Twister Message-ID: <20688554.1225739812100.JavaMail.root@viefep11.chello.at> I needed to measure the self-capacitance of a small coil (2.8-20 uH). I Connected U60-13 in Twister over a 8k2 resistor to the coil and the other side to ground. Then I put oscilloscope trigger on U60-13 and oscilloscope input to the coil. I have read out the ringing frequency (coil resonant frequency) and from the known inductance (I have an inductance meter) I have calculated the capacity which ranged from 12 to 14 pF :) The scope probe says "8.0pF" but doesn't say if it's the input or output capacitance, i. e. if I have to divide by 10 and the real input capacitance is 0.8pF. Anyone has an idea? KArel From asteri_x at freemail.hu Mon Nov 3 21:38:42 2008 From: asteri_x at freemail.hu (=?UTF-8?B?R3l1cmvDsyBNYXJ0aW4=?=) Date: Mon, 03 Nov 2008 22:38:42 +0100 Subject: [Ronja] Measuring capacitance of inductors with Twister In-Reply-To: <20688554.1225739812100.JavaMail.root@viefep11.chello.at> References: <20688554.1225739812100.JavaMail.root@viefep11.chello.at> Message-ID: <490F6F62.90005@freemail.hu> Careful! 1x usually is a normal koax cable 10x is something weird with the capacitance, and it is not so easy to say, especially when you adjust the probe with it's trimmer. I would guess it is the input cap. Direct using of 50 Ohm cable? would it destroy the measurement results? Martin Karel Kulhavy ?rta: > I needed to measure the self-capacitance of a small coil (2.8-20 uH). I Connected > U60-13 in Twister over a 8k2 resistor to the coil and the other side to ground. Then I > put oscilloscope trigger on U60-13 and oscilloscope input to the coil. I have read out > the ringing frequency (coil resonant frequency) and from the known inductance (I have an inductance meter) I have calculated the capacity which ranged from 12 to 14 pF :) > > The scope probe says "8.0pF" but doesn't say if it's the input or output capacitance, i. e. if I have to divide by 10 and the real input capacitance is 0.8pF. Anyone has an idea? > > KArel > From twibright at hispeed.ch Tue Nov 4 17:06:48 2008 From: twibright at hispeed.ch (Karel Kulhavy) Date: Tue, 4 Nov 2008 18:06:48 +0100 Subject: [Ronja] Measuring capacitance of inductors with Twister Message-ID: <1532935.1225818409141.JavaMail.root@viefep11.chello.at> ---- "Gyurk? Martin" schrieb: > Careful! 1x usually is a normal koax cable 10x is something weird with the capacitance, and it is not so easy to say, especially when you adjust the probe with it's trimmer. I would guess it is the input cap. > Direct using of 50 Ohm cable? > would it destroy the measurement results? I have upgraded the measurement. Used 93 Ohm cable terminated with 91 Ohm terminator into 1MOhm 13pF input of a 350 MHz Tektronix digital scope. In series with this is a 30kOhm resistor and the coil is between the resistor and output of a HC gate (Twister 60-13). It works fine and gives the capacitance directly without subtracting any probe capacitance (there is no probe) :) Karel > Martin From pedro.lopezestepa at epfl.ch Wed Nov 5 09:18:18 2008 From: pedro.lopezestepa at epfl.ch (pedro.lopezestepa at epfl.ch) Date: Wed, 05 Nov 2008 10:18:18 +0100 Subject: [Ronja] Ronja Drive Message-ID: <20081105101818.24m5fkgrlwg48kwg@webmail.epfl.ch> Hello, I decided to use the way in which you drive the LED in your transmission circuit. But I was wondering if all the NOT gates are needed in my case where the input is a clear square signal.(It would be also very nice if you could explain me the reason of having 15 NOTs) Thanks a lot! Pedro From twibright at hispeed.ch Thu Nov 6 14:36:48 2008 From: twibright at hispeed.ch (Karel Kulhavy) Date: Thu, 6 Nov 2008 15:36:48 +0100 Subject: [Ronja] Ronja Drive Message-ID: <1406267.1225982209410.JavaMail.root@viefep11.chello.at> ---- pedro.lopezestepa at epfl.ch schrieb: > Hello, > > I decided to use the way in which you drive the LED in your > transmission circuit. > But I was wondering if all the NOT gates are needed in my case where > the input is a clear square signal.(It would be also very nice if you > could explain me the reason of having 15 NOTs) Are you studing at Ecole Polytechnique Federale de Lausanne? As seen in the HC04 datasheet, the output current is rather limited, that's why the gates are tied in parallel to get a harder source of square wave voltage for the LED. The LED also has a capacitance and needs to be charged quickly. Karel From twibright at hispeed.ch Thu Nov 6 15:19:15 2008 From: twibright at hispeed.ch (Karel Kulhavy) Date: Thu, 6 Nov 2008 16:19:15 +0100 Subject: [Ronja] Ronja Drive Message-ID: <18486066.1225984765691.JavaMail.root@viefep11.chello.at> ---- pedro.lopezestepa at epfl.ch schrieb: > Hello, > > I decided to use the way in which you drive the LED in your > transmission circuit. > But I was wondering if all the NOT gates are needed in my case where > the input is a clear square signal.(It would be also very nice if you > could explain me the reason of having 15 NOTs) Oh sorry I see I replied to a bit different question. Are you asking like why there is not 15, but only 10 or 6 gates? I don't actually remember how I came to the number 15. It's 7 years ago. Maybe I wanted to have a hard enough drive so I took rather more than less without doing any math. Or maybe I took an oscilloscope and tried the amount of gates which produces nice signal. Karel > > Thanks a lot! > Pedro > > -- > Twibright Ronja mailing list http://ronja.twibright.com > Ronja at lists.pointless.net > http://pointless.net/mailman/listinfo/ronja From twibright at hispeed.ch Fri Nov 7 08:46:50 2008 From: twibright at hispeed.ch (Karel Kulhavy) Date: Fri, 7 Nov 2008 9:46:50 +0100 Subject: [Ronja] Plastic bolt availability Message-ID: <21389957.1226047611222.JavaMail.root@viefep11.chello.at> Hello I have created a special coil for Ronja RX which improves the range. It's made of 3 M5x40 plastic screws, cable ties and 0.3mm diameter enamel copper wire. Are M5x40 or longer plastic screws available at your place? The coil is wonderful has 2.63uH and 1.26pF, always the same, because they are defined by the exact geometry of the thread. It gives 5dB more gain compared to Bourns coil 1.5uH/0-3.45pf and doesn't suffer from Barkhausen noise! In case these M5 are not available worldwide someone will have to buy a bag and send them with TX diodes or RX PCB's. Karel From twibright at hispeed.ch Fri Nov 7 19:35:50 2008 From: twibright at hispeed.ch (Karel Kulhavy) Date: Fri, 7 Nov 2008 20:35:50 +0100 Subject: [Ronja] CA3140 availability Message-ID: <31392149.1226086551133.JavaMail.root@viefep12> I want to make a logarithmic ambient light measurement in the new Ronja RX. If the user has packetloss he will be able to see if the range of Ronja is large (darkness/twilight) or normal (daylight) or if there is sun on the optical path (no data get through). For this I need CA3140 opamp. My 3 suppliers all have it for reasonably cheap price. Would it be a problem for people from other parts of the world? Karel From bms at incunabulum.net Fri Nov 7 22:35:49 2008 From: bms at incunabulum.net (Bruce M Simpson) Date: Fri, 07 Nov 2008 22:35:49 +0000 Subject: [Ronja] CA3140 availability In-Reply-To: <31392149.1226086551133.JavaMail.root@viefep12> References: <31392149.1226086551133.JavaMail.root@viefep12> Message-ID: <4914C2C5.9030905@incunabulum.net> Karel Kulhavy wrote: > I want to make a logarithmic ambient light measurement in the new Ronja RX. > > If the user has packetloss he will be able to see if the range > of Ronja is large (darkness/twilight) or normal (daylight) or if there is sun on the optical path (no data get through). For this I need CA3140 opamp. My 3 suppliers all have it for reasonably cheap price. Would it be a problem for people from other parts of the world? > > Karel > > In stock UK http://www.rapidonline.com/Electronic-Components/Integrated-Circuits/Operational-Amplifiers/FET-op-amps/67381/kw/ca3140 http://uk.rs-online.com/web/search/searchBrowseAction.html?method=retrieveTfg&binCount=5&Ne=4294957561&Ntt=*ca3140*&Ntk=I18NBrandPartNumber&Nr=AND%28avl%3auk%2csearchDiscon_uk%3aN%29&Ntx=mode%2bmatchallpartial&N=4294955182&Nty=1&LanguageId=en http://uk.farnell.com/jsp/search/browse.jsp;jsessionid=LVHUTAG1WFVOYCQLCIQZLTQ?N=0&Ntk=gensearch_001&Ntt=ca3140&Ntx=&_requestid=201152 From bms at incunabulum.net Fri Nov 7 22:40:31 2008 From: bms at incunabulum.net (Bruce M Simpson) Date: Fri, 07 Nov 2008 22:40:31 +0000 Subject: [Ronja] Plastic bolt availability In-Reply-To: <21389957.1226047611222.JavaMail.root@viefep11.chello.at> References: <21389957.1226047611222.JavaMail.root@viefep11.chello.at> Message-ID: <4914C3DF.7000009@incunabulum.net> Karel Kulhavy wrote: > Hello > > I have created a special coil for Ronja RX which improves the range. It's made of > 3 M5x40 plastic screws, cable ties and 0.3mm diameter enamel copper wire. Are M5x40 or longer plastic screws available at your place? > http://uk.farnell.com/allthread/306-2685/screw-kit-cheese-head-m5-sizes/dp/3062685 is this it? this chap seems to have M5x40 as Nylon under model fixings: http://www.modelfixings.co.uk/nylon_screws.htm various 0.2mm copper wire available on farnell... > The coil is wonderful has 2.63uH and 1.26pF, always the same, because they are > defined by the exact geometry of the thread. It gives 5dB more gain compared to Bourns > coil 1.5uH/0-3.45pf and doesn't suffer from Barkhausen noise! > > In case these M5 are not available worldwide someone will have to buy a bag and send them with TX diodes or RX PCB's. > From twibright at hispeed.ch Sun Nov 9 19:15:23 2008 From: twibright at hispeed.ch (Karel Kulhavy) Date: Sun, 9 Nov 2008 20:15:23 +0100 Subject: [Ronja] Luxmeter working Message-ID: <16925299.1226258124587.JavaMail.root@viefep17> Hello I have built the new frontend with the logarithmic luxmeter. It produces voltage 0-8.5V according to the current through the photodiode (values predicted from calibration points): 0V 1.2nA 1V 4.6nA 2V 18nA 3V 70nA 4V 270nA 5V 1uA 6V 4uA 7V 16uA 8V 61uA 8.5V 120uA The dark current of the photodiode (SFH203) is max. 5nA according to the datasheet. For darkness it shows about 0.1V. When the diode is disconnected it shows even less. That means my circuit is more sensitive than the dark current of the photodiode. For extreme darkness the function is likely to be imprecise due to the -1 term in the Shockley diode equation. The original idea was to make 10x more light -> 1 volt more. But that was designed for diode emissivity factor n=1. As it came out, the emissivity factor in this case is n=1.7.Do you know wheter all diodes of the same type have the same emissivity factor? Karel From twibright at hispeed.ch Wed Nov 12 08:32:52 2008 From: twibright at hispeed.ch (Karel Kulhavy) Date: Wed, 12 Nov 2008 9:32:52 +0100 Subject: [Ronja] Is an opamp oscillator reliable? Message-ID: <5593315.1226478772490.JavaMail.root@viefep11.chello.at> I want to build an opamp multivibrator to power the onboard 48V generator. A circuit like http://hyperphysics.phy-astr.gsu.edu/hbase/Electronic/square.html However I have a feeling that the Barkhausen criterion is not met anywhere. The feedback with capacitor has to have 180 degree phase for Barkhausen to be met. This can never happen because the low pass filter has phase limiting to 0 for low frequencies and 90 for high frequencies. However intuitively I understand how it's supposed to work. How can this circuit work then? Any idea? Is this circuitreliable at all, then? I would like to avoid circuits which fail under certain temperature, supply voltage, or component tolerance for some people and work for others. Karel From antitron at web.de Wed Nov 12 12:27:54 2008 From: antitron at web.de (Thomas Egenhofer) Date: Wed, 12 Nov 2008 13:27:54 +0100 Subject: [Ronja] Is an opamp oscillator reliable? In-Reply-To: References: Message-ID: <1226492874.6423.10.camel@Nekomimi-host> > Subject: [Ronja] Is an opamp oscillator reliable? > To: Twibright Ronja > Message-ID: <5593315.1226478772490.JavaMail.root at viefep11.chello.at> > Content-Type: text/plain; charset=utf-8 > > I want to build an opamp multivibrator to power the onboard 48V generator. A circuit like > http://hyperphysics.phy-astr.gsu.edu/hbase/Electronic/square.html > > However I have a feeling that the Barkhausen criterion is not met anywhere. The feedback with capacitor has to have 180 degree phase for Barkhausen to be met. This can never happen because the low pass filter has phase limiting to 0 for low frequencies and 90 for high frequencies. However intuitively I understand how it's supposed to work. > > How can this circuit work then? Any idea? Is this circuitreliable at all, then? > > I would like to avoid circuits which fail under certain temperature, supply voltage, > or component tolerance for some people and work for others. as far as i know those things work perfectly fine. their frequency is not very stable and can variate by several percent. same with the duty cycle. but it keeps working as such as long as the OP-amp is not broken and input voltage is present. you could also use 74hc14 if you use 5V input voltage. if you are in need of a higher supply-voltage take a look at some "single-use-cameras with flash" they use only a single transistor, a coil , diode and cap and they reach 200V without problems. some sort of self-oszillating circuit.but op-amp&cascade is more reliable than flash-thing-step-up. slightly off-topic: but it looks like pitch-black-analog-movie material can make some quite good IR-pass filters. since they usualy are 35mm square they could be placed quite easy in front of the receiver diodes for IR-based systems. looks like color-dia-film material works best. have no numbers on the filtering itself. but might be intresting for people with daylight-problems. From arunk at speedpost.net Wed Nov 12 17:56:52 2008 From: arunk at speedpost.net (Arun Krishnan) Date: Wed, 12 Nov 2008 23:26:52 +0530 Subject: [Ronja] The inductor block in a NIC. Message-ID: <1226512612.3112.1284409663@webmail.messagingengine.com> Hey guys, I have a question. I have noticed that there is a component right after the RJ45 connector in NICs which I deduce is an inductor block of some sort. These are present just about on everything with a 10/100BaseT port on them. My wireless router's WAN port died a couple days ago after a lightning strike and it looks like this thing has died (as the port blinks on self test and the inductor is open across pins which are short on the other ports). The part number printed on it is HN1664 and I can't find this thing anywhere for purchase. My question is, what exactly does this thing do and can I bypass it? I looked through my collection of NICs and none of their blocks have the same pin count as the one in the router, so I'm sorta out of options. Advice much appreciated. Regards, Arun From asteri_x at freemail.hu Thu Nov 13 23:17:50 2008 From: asteri_x at freemail.hu (=?UTF-8?B?R3l1cmvDsyBNYXJ0aW4=?=) Date: Fri, 14 Nov 2008 00:17:50 +0100 Subject: [Ronja] Is an opamp oscillator reliable? In-Reply-To: <5593315.1226478772490.JavaMail.root@viefep11.chello.at> References: <5593315.1226478772490.JavaMail.root@viefep11.chello.at> Message-ID: <491CB59E.3020702@freemail.hu> I have a working design with this type of oszillator. But I had problems with the single ended ground. It didnt oscillate when i had no middle ground on a 5V system and not rail-to-rail opamps. So i had to generate 2.5V with some resistors an make it clean with a C and then it worked perfectly. Try it! Bye Martin Karel Kulhavy ?rta: > I want to build an opamp multivibrator to power the onboard 48V generator. A circuit like > http://hyperphysics.phy-astr.gsu.edu/hbase/Electronic/square.html > > However I have a feeling that the Barkhausen criterion is not met anywhere. The feedback with capacitor has to have 180 degree phase for Barkhausen to be met. This can never happen because the low pass filter has phase limiting to 0 for low frequencies and 90 for high frequencies. However intuitively I understand how it's supposed to work. > > How can this circuit work then? Any idea? Is this circuitreliable at all, then? > > I would like to avoid circuits which fail under certain temperature, supply voltage, > or component tolerance for some people and work for others. > > Karel > From sr6220305 at yahoo.com Fri Nov 14 18:51:53 2008 From: sr6220305 at yahoo.com (Sean Ramdeholl) Date: Fri, 14 Nov 2008 10:51:53 -0800 (PST) Subject: [Ronja] Plastic bolt availability In-Reply-To: <4914C3DF.7000009@incunabulum.net> Message-ID: <799378.22679.qm@web55507.mail.re4.yahoo.com> Standardized special screws exclusively emphasized in various, such as plastic screws...: http://www.e-nedzi.com/product/spvc-h/index_en.html Sean Ramdeholl --- On Fri, 11/7/08, Bruce M Simpson wrote: From: Bruce M Simpson Subject: Re: [Ronja] Plastic bolt availability To: "Twibright Ronja" Date: Friday, November 7, 2008, 6:40 PM Karel Kulhavy wrote: > Hello > > I have created a special coil for Ronja RX which improves the range. It's made of > 3 M5x40 plastic screws, cable ties and 0.3mm diameter enamel copper wire. Are M5x40 or longer plastic screws available at your place? > http://uk.farnell.com/allthread/306-2685/screw-kit-cheese-head-m5-sizes/dp/3062685 is this it? this chap seems to have M5x40 as Nylon under model fixings: http://www.modelfixings.co.uk/nylon_screws.htm various 0.2mm copper wire available on farnell... > The coil is wonderful has 2.63uH and 1.26pF, always the same, because they are > defined by the exact geometry of the thread. It gives 5dB more gain compared to Bourns > coil 1.5uH/0-3.45pf and doesn't suffer from Barkhausen noise! > > In case these M5 are not available worldwide someone will have to buy a bag and send them with TX diodes or RX PCB's. > -- Twibright Ronja mailing list http://ronja.twibright.com 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/20081114/023b2f60/attachment.html From russ at coldstonelabs.org Thu Nov 20 17:46:42 2008 From: russ at coldstonelabs.org (Russell Valentine) Date: Thu, 20 Nov 2008 11:46:42 -0600 Subject: [Ronja] Twister2 Storage Temperatures Message-ID: <4925A282.6070407@coldstonelabs.org> Is it safe to store the Twister2 is less than 0C temperature? I realize http://ronja.twibright.com/tetrapolis/spec.php shows operating temperature, but I don't see a storage temperature listed. Russell Valentine From twibright at hispeed.ch Thu Nov 20 20:03:59 2008 From: twibright at hispeed.ch (Karel Kulhavy) Date: Thu, 20 Nov 2008 21:03:59 +0100 Subject: [Ronja] Twister2 Storage Temperatures Message-ID: <5165988.1227211444898.JavaMail.root@viefep15> ---- Russell Valentine schrieb: > Is it safe to store the Twister2 is less than 0C temperature? Yes it is if it's soldered by leaded solder. That reminds me I should throw the lead-free solder out of the material list, because I have read somewhere that if stored in freezing temperatures for a long time, the lead free solder can fall apart. I wonder what application might require storage in freezing temperature because Twister2 is meant to be operated indoors and people also usually store indoors. Karel > > I realize http://ronja.twibright.com/tetrapolis/spec.php shows operating > temperature, but I don't see a storage temperature listed. > > > Russell Valentine > > -- > Twibright Ronja mailing list http://ronja.twibright.com > Ronja at lists.pointless.net > http://pointless.net/mailman/listinfo/ronja From russ at coldstonelabs.org Thu Nov 20 21:30:46 2008 From: russ at coldstonelabs.org (Russell Valentine) Date: Thu, 20 Nov 2008 15:30:46 -0600 Subject: [Ronja] Twister2 Storage Temperatures In-Reply-To: <5165988.1227211444898.JavaMail.root@viefep15> References: <5165988.1227211444898.JavaMail.root@viefep15> Message-ID: <4925D706.2040709@coldstonelabs.org> Karel Kulhavy wrote: > ---- Russell Valentine schrieb: >> Is it safe to store the Twister2 is less than 0C temperature? > > Yes it is if it's soldered by leaded solder. That reminds me I should throw the lead-free solder out of the material list, because I have read somewhere that if > stored in freezing temperatures for a long time, the lead free solder can fall apart. > > I wonder what application might require storage in freezing temperature because Twister2 > is meant to be operated indoors and people also usually store indoors. > I might need to store the twister in a car for a few days where the temperature at night will get below freezing, so I was just curious. Thank you for your answer. Russell Valentine From kubajz at kbx.cz Mon Nov 24 22:38:50 2008 From: kubajz at kbx.cz (Jakub Sykora) Date: Mon, 24 Nov 2008 23:38:50 +0100 Subject: [Ronja] Twister2 Storage Temperatures In-Reply-To: <4925D706.2040709@coldstonelabs.org> References: <5165988.1227211444898.JavaMail.root@viefep15> <4925D706.2040709@coldstonelabs.org> Message-ID: <492B2CFA.6000506@kbx.cz> Another "good" solution is to leave the motor running all time to meet operation conditions of twister :)) K Russell Valentine wrote: > Karel Kulhavy wrote: >> ---- Russell Valentine schrieb: >>> Is it safe to store the Twister2 is less than 0C temperature? >> Yes it is if it's soldered by leaded solder. That reminds me I should throw the lead-free solder out of the material list, because I have read somewhere that if >> stored in freezing temperatures for a long time, the lead free solder can fall apart. >> >> I wonder what application might require storage in freezing temperature because Twister2 >> is meant to be operated indoors and people also usually store indoors. >> > > I might need to store the twister in a car for a few days where the > temperature at night will get below freezing, so I was just curious. > Thank you for your answer. > > > Russell Valentine > -- Jakub S?kora email: kubajz na kbx.cz <') ICQ: 68976632 ( =- mobil: +420 777 594 201 '' From cd930 at centrum.cz Wed Nov 26 22:38:24 2008 From: cd930 at centrum.cz (CD930) Date: Wed, 26 Nov 2008 23:38:24 +0100 Subject: [Ronja] 32km FSO Message-ID: >From HAM world...... http://www.ok2kkw.com/next/qw2008_33km.htm and audio: http://www.ok2kkw.com/laser33km.mp3 Martin OK1MJO ------------- dal?? ??st --------------- HTML p??loha byla odstran?na... URL: http://pointless.net/pipermail/ronja/attachments/20081126/e3a74e17/attachment.html From twibright at hispeed.ch Thu Nov 27 09:54:10 2008 From: twibright at hispeed.ch (Karel Kulhavy) Date: Thu, 27 Nov 2008 10:54:10 +0100 Subject: [Ronja] Neco se deje Message-ID: <30551611.1227779653022.JavaMail.root@viefep11.chello.at> Dostal jsem pocit, ze bych asi mel vyvoj na projektu Ronja do odvolani zastavit. Tezko se takova nahla a radikalni zmena vysvetluje tak jsem se rozhodl to vysvetlit formou pohadky: Mimozemstane leteli okolo planety 465B Tektronix a rozhodli se, ze nehostinnou planetu osidli nejakym zivotem. Vysadili proto na planetu samorozmnozujici se osciloskopy. Takovy osciloskop je slozity elektronicky pristroj, s kterym se daji delat uzasne veci, a ma na prednim panelu spoustu cudliku, kterymi se funkce nastavuji a prepinaji. Jeho dusevni funkce jsou ale pomerne omezene, takze mu jde uvazovani pomalu a obtizne. Na planete se rodily nove osciloskopy a kazdy osciloskop pri narozeni mel cudliky nahodne nastavene. Osciloskopy si vsimly, ze kazdy ma jine nastaveni a ze kazdy je schopen delat jenom jednu funkci - tu ktera mu byla sudickami pri zrozeni nastavena. Jednim z osciloskopu byl i Jay, kteremu zaclo byt lito, ze on muze delat jen jednu funkci. Zatouzil zjisti, jak obvody uvnitr jeho sameho funguji, a snil o tom, ze svoje cudliky bude moct prepinat a tak zpristupnit drive nevidane obzory svych moznosti. Nejdriv ho napadlo, jestli mimozemstani nekde na planete nezanechali manual. Hledal po cele planete ale zjistil, ze zadny manual neexistuje. Po namahavem cestovani sedela doma sklesle v beznadeji, ze se jeho sen nikdy nevyplni. Pak ho napadlo, jestli by nemohl cudliky na sobe prepinat a koukat se, jaky to bude mit vliv na jeho funkci. Zjistil ale, ze cudliky jsou za roky jeho zivota tak zarezle a zacpane hlinou, ze se daji prepinat jen velmi stezi. Tudy cesta nevedla. Jay byl opet sklesly a bylo mu smutno, ze jeho sen se zhroutil. K cemu by mu bylo znat funkci cudliku, kdyz je stejne skoro nejde prepinat? Pak ho neco napadlo. To mu sice k nicemu nebude, ale kdyz bude znat funkci cudliku, bude moct predvidat, jak se budou chovat ostatni osciloskopy protoze je videt, jak jsou cudliky na jejich prednim panelu nastavene. Kdyz bude chtit pouzit nejakou funkci, staci kdyz vyhleda osciloskop ktery bude mit to spravne nastaveni. Takze se k neprebernemu spektru funkci prece jen dostane! Jay zajasal, a zacal premyslet, jestli by prece jen funkci cudliku nejak zjistit. Najednou dostal napad. Zacal chodit po planete a bavit se se vsemi moznymi osciloskopy. Kazdeho se ptal na jeho zivot a z toho pak poznal, jake nastaveni cudliku vede k jake funkci. Srovnaval pribehy ruznych osciloskopu, premyslel o nich a postupem casu zacal byt s velo veci familiarni a zacal tusit, jak veci uvnitr funguji. Jay tak ziskal spoustu kamaradu. Vybaven znalosti o tom jak on sam funguje uvnitr, Jay pak byl schopen v pripade nutnosti s vynalozenim veskere namahy prepnout nektere cudliky na svem prednim panelu a tak svoji funkci zmenit. A kdyz potreboval pouzit nejakou funkci kterou sam nastavit nedokazal, vzpomnel si na jednoho ze svych kamaradu, kteri funkci na sobe nahodou meli od narozeni, a na toho se obratil. Ostatni osciloskopy si brzo zacaly vsimat, ze Jay ma nejake neobvykle schopnosti. Ptaly se ho, jak to dela a on jim popsal, na co prisel. Brzo se vsechny osciloskopy zacaly schazet a poradat party a vecirky kde se o sobe navzajem bavili. Planeta 465B Tektronix zacla zit svym vlatnim plechovym spolecenskym zivotem. Karel From stephanusr at gmail.com Fri Nov 28 15:17:26 2008 From: stephanusr at gmail.com (Stephanus Rensburg) Date: Fri, 28 Nov 2008 17:17:26 +0200 Subject: [Ronja] Repeater hops with Ronja Message-ID: <513680dc0811280717q2967ff70lf54e12e7bd2a5374@mail.gmail.com> How many repeater nodes can be created before latency becomes an issue? With repeater I mean to connect two Ronjas back to back via a switch. From twibright at hispeed.ch Fri Nov 28 16:25:11 2008 From: twibright at hispeed.ch (Karel Kulhavy) Date: Fri, 28 Nov 2008 17:25:11 +0100 Subject: [Ronja] Repeater hops with Ronja Message-ID: <3787042.1227889512816.JavaMail.root@viefep11.chello.at> ---- Stephanus Rensburg schrieb: > How many repeater nodes can be created before latency becomes an > issue? With repeater I mean to connect two Ronjas back to back via a > switch. It's the same as with optical fiber. Practically unlimited and depends on the particular switch type (cut through or store forward). Karel From stephanusr at gmail.com Sat Nov 29 17:05:38 2008 From: stephanusr at gmail.com (Stephanus Rensburg) Date: Sat, 29 Nov 2008 19:05:38 +0200 Subject: [Ronja] Parabolic reflector at Tx and lens receiver at Rx Message-ID: <513680dc0811290905n1b13bc0dpd552059b9270241b@mail.gmail.com> I read through the documentation and it seems to me that Ronja don't use a parabolic focusing reflector at the Tx side only a 100mm focusing lens at the receiver side. http://www.roithner-laser.com sells parabolic beam Tx focusing reflectors. This will increase the range of the ronja by a multitude. From russ at coldstonelabs.org Sat Nov 29 23:15:16 2008 From: russ at coldstonelabs.org (Russell Valentine) Date: Sat, 29 Nov 2008 17:15:16 -0600 Subject: [Ronja] RONJA and Manchester encoding Message-ID: <4931CD04.6090906@coldstonelabs.org> I was trying to understand how the RONJA works some more. If I am to understand this correctly the Manchester encoding used in 10BASE-T has a maximum frequency of 20Mhz. The TX discriminator seems to run off 16Mhz. This blows my mind. Is it that 16Mhz is close enough that it works, or what am I missing something? Thank you for your time. Russell Valentine