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#1
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NFB 101 Part Deux
Sorry it has been a while coming but I have just finished part two of
NFB 101. I found I could not describe it properly without diagrams and proper equations so I had to resort to using a word processor and converting the result into a pdf, all of which took time. So point your browser he http://www.ianbell.ukfsn.org/data/nfb101.pdf to download it. Cheers Ian |
#2
Posted to rec.audio.tubes
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NFB 101 Part Deux
Ian Thompson-Bell wrote:
Sorry it has been a while coming but I have just finished part two of NFB 101. I found I could not describe it properly without diagrams and proper equations so I had to resort to using a word processor and converting the result into a pdf, all of which took time. So point your browser he http://www.ianbell.ukfsn.org/data/nfb101.pdf to download it. Cheers Ian Thanks, Ian. Just printed it out to read later. |
#3
Posted to rec.audio.tubes
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NFB 101 Part Deux
"Ian Thompson-Bell" wrote in message ... Sorry it has been a while coming but I have just finished part two of NFB 101. I found I could not describe it properly without diagrams and proper equations so I had to resort to using a word processor and converting the result into a pdf, all of which took time. So point your browser he http://www.ianbell.ukfsn.org/data/nfb101.pdf to download it. Excellent Ian. I have just printed this out for bedtime reading. And just as Andre had reported there was nothing happening. Your timing was impeccable:-) Iain |
#4
Posted to rec.audio.tubes
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NFB 101 Part Deux
Iain Churches wrote:
"Ian Thompson-Bell" wrote in message ... Sorry it has been a while coming but I have just finished part two of NFB 101. I found I could not describe it properly without diagrams and proper equations so I had to resort to using a word processor and converting the result into a pdf, all of which took time. So point your browser he http://www.ianbell.ukfsn.org/data/nfb101.pdf to download it. Excellent Ian. I have just printed this out for bedtime reading. And just as Andre had reported there was nothing happening. Your timing was impeccable:-) Iain There may be typos in it still. I changed all the text based formulae to 'proper' ones so something may have got lost in translation. There are certainly some superfluous brackets lying around only because I have not yet worked out how to get the formula editor to suppress them. And I am not sure if the figures tie up exactly with the text and of course it is nowhere near finished yet. Cheers Ian |
#5
Posted to rec.audio.tubes
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NFB 101 Part Deux
Ian Thompson-Bell wrote: Iain Churches wrote: "Ian Thompson-Bell" wrote in message ... Sorry it has been a while coming but I have just finished part two of NFB 101. I found I could not describe it properly without diagrams and proper equations so I had to resort to using a word processor and converting the result into a pdf, all of which took time. So point your browser he http://www.ianbell.ukfsn.org/data/nfb101.pdf to download it. Excellent Ian. I have just printed this out for bedtime reading. And just as Andre had reported there was nothing happening. Your timing was impeccable:-) Iain There may be typos in it still. I changed all the text based formulae to 'proper' ones so something may have got lost in translation. There are certainly some superfluous brackets lying around only because I have not yet worked out how to get the formula editor to suppress them. And I am not sure if the figures tie up exactly with the text and of course it is nowhere near finished yet. Cheers Ian Good work Ian. RDH4 has all this spelled out of course, and uses , "mu" for amplification factor and "beta" for fraction of output voltage either in series with input voltage for series voltage NFB or in shunt with applied NFB as in shunt voltage NFB. RDH4 lists all the many varieties of feedback, both positive and negative, and current and voltage types and whether it is shunt or series. RDH4 also has a table to show what the effects are of all the different types of NFB. But not every single fascinating aspect of feedback is explored in RHD4. For example, did you know that positive "series" current feedback will reduce the output resistance of any amplifier, but at the cost of reducing bandwidth and increasing distortions? If we consider a "normal" amp response of having a reducing output voltage as the RL becomes lower as having a POSITIVE output resistance, then the positive CFB can reduce this amount of Rout to a lesser value; a typical ultralinear amp with say Ro = 7 ohms with PCFB can easily have its Rout reduced to say 1 ohm. We assume Rout has been reduced from +7 ohms to +1 ohm. Then the application of the global series voltage "normal" NFB will reduce it even more to a lower value along with all distortions of the amp and those produced by the PCFB applied internally. We can even apply so much PFFB that the positive Ro becomes a NEGATIVE output resistance, and the result is that output voltage rises when RL value is reduced. So +1 ohm can be reduced further so Rout = ZERO ohms, then even less than zero ohms, ie maybe -1ohm. Obviously, such negative Ro tempts fate and credulity because its impossible to get an amp which makes say 16Vrms at clipping into 8 ohms to make 20Vrms into 1 ohm. But it is possible to make the same amp which makes 1.6V into 8 ohms deliver 2V into 1 ohms. But we would find this difficult to live with; once you examine how its done, and experiment with it, there are definate stability issues, and the open loop gain ( OLG ) must be reduced or phase tailored to prevent oscilations, and the application of the PCFB be prevented at extremities of LF and HF bandwidth. Very interesting, but don't say I have not warned you. The maths involved around each different form of feedback will take you another 20 pages to explain. I do suggest that all your terms for RL, Ra, and all others be made the same as in RDH4, because it was a good standard and everyone should know it, and that equations be written in the same way. In your theoretical workings for NFB application, how about showing some typical tube power amplifier schematics with NFB applied with all working voltages with their polarities so ppl can measure their own amps and understand it all a lot better? Using a triangle pointing to the right to represent an amp with two inputs on the left vertical side and one output at the right point is the text book way to represent an amp so people do not have to keep in mind all the complex inner amp topology which distracts them from the basic idea. The same model can then be used for a tube amp or an opamp. However, to include all possible phase shift peculiarities of the open loop character of an amp and the equivalent networks in the amp which produce them and their interaction when FB is used takes rather a lot of work. NFB theory and application has already covered in many old books, and many should be found then read, and the messages in each will overlap each other books's shortcomings, and you end up wize while you remember it all, then dumb again when you forget it all. Unless of course all you do all day everyday is design and stabilise new and old amplifiers. I probably do enough to keep me wize. I have never seen an online calculator for NFB, where one dials in the details of the open loop gain and all its phase shift rates and bothers, and then ask for 20dB of NFB, and click "calculate", and have the program come up with the FB network and including all the phase tweaking networks needed for unconditional stability into any possible type of reactive loading, R load, or no load at all. Such a program could possibly be a boon for the dumbos to whom feedback is a terrible mystery, and always will be, and hence hated fiercely, and avoided. But with a programmed or synthesized solution, one must ensure it is still a viable solution which works in practice. Since garbage in = garbage out with simulation programs, expect many simulated solutions using tubes and OPTs to still be good oscillators when nobody expected it. That's because its difficult for anyone to correctly define all the open loop gain and phase shift character. Too ****ing hard. Just bulid it, and learn to stabilise it by empirical methods of network applications and trial and error and by observation with a CRO. This is a far quicker way than all the calculations in the world sitting down at a table when you should be in the workshop achieving something real. Models of the single tube amplifier stage should include an extremely low voltage generator producing output of x Vg with series resistance between the gene output and the anode terminal should be explained as equivalent models of the triode or pentode ot any other tube. Newbies NEED to know the very boring basics before thay can have any chance of understanding. Most don't have a clue what a voltage generator is, or what the dynamic anode resistance is at all!!! I welcome you to borrow whatever you need from http://www.turneraudio.com.au/tube-operation1.html and http://www.turneraudio.com.au/tube-operation3.html I don't have all the possible various feedback applications mentiuoned at my site. It is to be expected that the learning tube crafter will absorb the basic ideas and be able to perform all the basic calculations for normal series and shunt VOLTAGE NFB. The equations for gain with FB applied are slightly different for the these two main types of NFB. Since NOBODY ever dares to apply any positive voltage or current feedback anywhere anymore to any amp whatsoever, I have not mentioned exactly how it can be done successfully, because the risks of parasitic oscillations are so likely in the hands of ignorant would be experts. In general with low triode input/drivers, tube amplifiers have only a mild amount of voltage gain without any NFB applied, ie, "open loop" gain. And this "OLG", open loop gain is then reduced by the OPT voltage ratio. So, to force the amp to have an apparently larger amount of open loop gain, some positive voltage FB or positive current FB was applied and the resulting amp with mild applications of standard series voltage global negative FB measured far better than with just standard global series voltage NFB applied alone. Its all mentioned in RDH4. There was classic application of combined forms of FB in a commercial example in Bogan amps which had variable positive FB to vary the damping factor of their amps and it gave better sounding bass we have been told. But such fiddles with FB or active manipulations of Rout are to be treated with utmost caution. With too much positive current FB, a shorted output can make an amp oscillate internally very violently, and cause its demise from thermal runaway of the output tubes, so too much PCFB is extremely undesirable. A little dab of PCFB goes a long way and is extremely effective in reducing Rout a lot though without increasing the bad artifacts of reduced BW and distortions very much. In SS amps, nobody ever would use old fashioned tricks of positive FB anywhere because the total including the input LTP, VAS and output BJTs of mosfets is over 100,000x, or more than 80dB, so when a TOTAL amount of series voltage NFB is applied in the form of say 30dB emitter or source FB in the output stage and 50dB of global NFB, the gross distortions of crossover and THD and IMD in the OLG charateristic are reduced to well below what is ever possible to be heard. Well, in theory that is, because often some ratbag ****ant 20 watt SE tube amp will give a clearer rendition of what Motzart or Led Zeppilin intended than some 100W SS thinge, and despite the fact the SE amp will have very little NFB and have 100 times the measured THD/IMD than the SS amp. Numbers ain't everything. Patrick Turner. |
#6
Posted to rec.audio.tubes
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NFB 101 Part Deux
Patrick Turner wrote:
Good work Ian. RDH4 has all this spelled out of course, and uses , "mu" for amplification factor and "beta" for fraction of output voltage either in series with input voltage for series voltage NFB or in shunt with applied NFB as in shunt voltage NFB. Yes I wanted to use the proper symbols but I took me so long to get my head around the word processors formula editor that I never got round to working out how to do special characters. I will revise that aspect though. RDH4 lists all the many varieties of feedback, both positive and negative, and current and voltage types and whether it is shunt or series. RDH4 also has a table to show what the effects are of all the different types of NFB. But not every single fascinating aspect of feedback is explored in RHD4. For example, did you know that positive "series" current feedback will reduce the output resistance of any amplifier, but at the cost of reducing bandwidth and increasing distortions? If we consider a "normal" amp response of having a reducing output voltage as the RL becomes lower as having a POSITIVE output resistance, then the positive CFB can reduce this amount of Rout to a lesser value; a typical ultralinear amp with say Ro = 7 ohms with PCFB can easily have its Rout reduced to say 1 ohm. We assume Rout has been reduced from +7 ohms to +1 ohm. Then the application of the global series voltage "normal" NFB will reduce it even more to a lower value along with all distortions of the amp and those produced by the PCFB applied internally. We can even apply so much PFFB that the positive Ro becomes a NEGATIVE output resistance, and the result is that output voltage rises when RL value is reduced. So +1 ohm can be reduced further so Rout = ZERO ohms, then even less than zero ohms, ie maybe -1ohm. Obviously, such negative Ro tempts fate and credulity because its impossible to get an amp which makes say 16Vrms at clipping into 8 ohms to make 20Vrms into 1 ohm. But it is possible to make the same amp which makes 1.6V into 8 ohms deliver 2V into 1 ohms. But we would find this difficult to live with; once you examine how its done, and experiment with it, there are definate stability issues, and the open loop gain ( OLG ) must be reduced or phase tailored to prevent oscilations, and the application of the PCFB be prevented at extremities of LF and HF bandwidth. Very interesting, but don't say I have not warned you. The maths involved around each different form of feedback will take you another 20 pages to explain. I do suggest that all your terms for RL, Ra, and all others be made the same as in RDH4, because it was a good standard and everyone should know it, and that equations be written in the same way. Clearly RDH4 has covered this material in some detail and I did include a link to chapter 7 saying I was not going to repeat that chapter. The question is what is the right balance for RAT readers, especially noobies as this is supposed to be NFB101 and it is already bogged down in maths. Personally I like the analysis to be clear without such things as 'this can be expressed as' without any attendant explanation. Obviously it needs to be heavily tube related so I thought after the CF I would do he unbypassed CC followed by shunt derived and applied FB around a triode of pentode stage mainly because they are easier to understand and there are no stability problems. Next I thought I would cover the classic two stage shunt fed series applied circuit which leads nicely into stability issues. In your theoretical workings for NFB application, how about showing some typical tube power amplifier schematics with NFB applied with all working voltages with their polarities so ppl can measure their own amps and understand it all a lot better? That sounds like a good idea. Using a triangle pointing to the right to represent an amp with two inputs on the left vertical side and one output at the right point is the text book way to represent an amp so people do not have to keep in mind all the complex inner amp topology which distracts them from the basic idea. The same model can then be used for a tube amp or an opamp. I purposely avoided that because its common usage is to represent an amplifier with infinite gain, zero output resistance and infinite input impedance and as we both know, tubes only meet one of those criteria. I was trying to emphasize that tubes fall far short of this ideal which is why many of the op-amp simplifications just don't apply to tubes. However, to include all possible phase shift peculiarities of the open loop character of an amp and the equivalent networks in the amp which produce them and their interaction when FB is used takes rather a lot of work. NFB theory and application has already covered in many old books, and many should be found then read, and the messages in each will overlap each other books's shortcomings, and you end up wize while you remember it all, then dumb again when you forget it all. Unless of course all you do all day everyday is design and stabilise new and old amplifiers. I probably do enough to keep me wize. I have never seen an online calculator for NFB, where one dials in the details of the open loop gain and all its phase shift rates and bothers, and then ask for 20dB of NFB, and click "calculate", and have the program come up with the FB network and including all the phase tweaking networks needed for unconditional stability into any possible type of reactive loading, R load, or no load at all. Such a program could possibly be a boon for the dumbos to whom feedback is a terrible mystery, and always will be, and hence hated fiercely, and avoided. But with a programmed or synthesized solution, one must ensure it is still a viable solution which works in practice. Since garbage in = garbage out with simulation programs, expect many simulated solutions using tubes and OPTs to still be good oscillators when nobody expected it. That's because its difficult for anyone to correctly define all the open loop gain and phase shift character. Too ****ing hard. Just bulid it, and learn to stabilise it by empirical methods of network applications and trial and error and by observation with a CRO. This is a far quicker way than all the calculations in the world sitting down at a table when you should be in the workshop achieving something real. Models of the single tube amplifier stage should include an extremely low voltage generator producing output of x Vg with series resistance between the gene output and the anode terminal should be explained as equivalent models of the triode or pentode ot any other tube. Newbies NEED to know the very boring basics before thay can have any chance of understanding. Most don't have a clue what a voltage generator is, or what the dynamic anode resistance is at all!!! An interesting point. Do you think NFB101 should start with a statement of what knowledge is assumed along with pointers to references for those who don't have it? I welcome you to borrow whatever you need from http://www.turneraudio.com.au/tube-operation1.html and http://www.turneraudio.com.au/tube-operation3.html I don't have all the possible various feedback applications mentiuoned at my site. Thanks for the permission to use ingfo from your site. Cheers Ian |
#7
Posted to rec.audio.tubes
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NFB 101 Part Deux
Ian Thompson-Bell wrote: Patrick Turner wrote: Good work Ian. RDH4 has all this spelled out of course, and uses , "mu" for amplification factor and "beta" for fraction of output voltage either in series with input voltage for series voltage NFB or in shunt with applied NFB as in shunt voltage NFB. Yes I wanted to use the proper symbols but I took me so long to get my head around the word processors formula editor that I never got round to working out how to do special characters. I will revise that aspect though. RDH4 lists all the many varieties of feedback, both positive and negative, and current and voltage types and whether it is shunt or series. RDH4 also has a table to show what the effects are of all the different types of NFB. But not every single fascinating aspect of feedback is explored in RHD4. For example, did you know that positive "series" current feedback will reduce the output resistance of any amplifier, but at the cost of reducing bandwidth and increasing distortions? If we consider a "normal" amp response of having a reducing output voltage as the RL becomes lower as having a POSITIVE output resistance, then the positive CFB can reduce this amount of Rout to a lesser value; a typical ultralinear amp with say Ro = 7 ohms with PCFB can easily have its Rout reduced to say 1 ohm. We assume Rout has been reduced from +7 ohms to +1 ohm. Then the application of the global series voltage "normal" NFB will reduce it even more to a lower value along with all distortions of the amp and those produced by the PCFB applied internally. We can even apply so much PFFB that the positive Ro becomes a NEGATIVE output resistance, and the result is that output voltage rises when RL value is reduced. So +1 ohm can be reduced further so Rout = ZERO ohms, then even less than zero ohms, ie maybe -1ohm. Obviously, such negative Ro tempts fate and credulity because its impossible to get an amp which makes say 16Vrms at clipping into 8 ohms to make 20Vrms into 1 ohm. But it is possible to make the same amp which makes 1.6V into 8 ohms deliver 2V into 1 ohms. But we would find this difficult to live with; once you examine how its done, and experiment with it, there are definate stability issues, and the open loop gain ( OLG ) must be reduced or phase tailored to prevent oscilations, and the application of the PCFB be prevented at extremities of LF and HF bandwidth. Very interesting, but don't say I have not warned you. The maths involved around each different form of feedback will take you another 20 pages to explain. I do suggest that all your terms for RL, Ra, and all others be made the same as in RDH4, because it was a good standard and everyone should know it, and that equations be written in the same way. Clearly RDH4 has covered this material in some detail and I did include a link to chapter 7 saying I was not going to repeat that chapter. The question is what is the right balance for RAT readers, especially noobies as this is supposed to be NFB101 and it is already bogged down in maths. Personally I like the analysis to be clear without such things as 'this can be expressed as' without any attendant explanation. Obviously it needs to be heavily tube related so I thought after the CF I would do he unbypassed CC followed by shunt derived and applied FB around a triode of pentode stage mainly because they are easier to understand and there are no stability problems. Next I thought I would cover the classic two stage shunt fed series applied circuit which leads nicely into stability issues. In your theoretical workings for NFB application, how about showing some typical tube power amplifier schematics with NFB applied with all working voltages with their polarities so ppl can measure their own amps and understand it all a lot better? That sounds like a good idea. Using a triangle pointing to the right to represent an amp with two inputs on the left vertical side and one output at the right point is the text book way to represent an amp so people do not have to keep in mind all the complex inner amp topology which distracts them from the basic idea. The same model can then be used for a tube amp or an opamp. I purposely avoided that because its common usage is to represent an amplifier with infinite gain, zero output resistance and infinite input impedance and as we both know, tubes only meet one of those criteria. I was trying to emphasize that tubes fall far short of this ideal which is why many of the op-amp simplifications just don't apply to tubes. But even with an opamp with huge open loop gains and supposedly huge Rin, the actual OLG and OL BW ( open loop bandwidth ) can be stated as easily as the BASIC OL BW of a tube amp. The calculations should always include a drawn model of the amp with whatever BASIC resistances/impedances which affect the aplication of NFB. However, to include all possible phase shift peculiarities of the open loop character of an amp and the equivalent networks in the amp which produce them and their interaction when FB is used takes rather a lot of work. NFB theory and application has already covered in many old books, and many should be found then read, and the messages in each will overlap each other books's shortcomings, and you end up wize while you remember it all, then dumb again when you forget it all. Unless of course all you do all day everyday is design and stabilise new and old amplifiers. I probably do enough to keep me wize. I have never seen an online calculator for NFB, where one dials in the details of the open loop gain and all its phase shift rates and bothers, and then ask for 20dB of NFB, and click "calculate", and have the program come up with the FB network and including all the phase tweaking networks needed for unconditional stability into any possible type of reactive loading, R load, or no load at all. Such a program could possibly be a boon for the dumbos to whom feedback is a terrible mystery, and always will be, and hence hated fiercely, and avoided. But with a programmed or synthesized solution, one must ensure it is still a viable solution which works in practice. Since garbage in = garbage out with simulation programs, expect many simulated solutions using tubes and OPTs to still be good oscillators when nobody expected it. That's because its difficult for anyone to correctly define all the open loop gain and phase shift character. Too ****ing hard. Just bulid it, and learn to stabilise it by empirical methods of network applications and trial and error and by observation with a CRO. This is a far quicker way than all the calculations in the world sitting down at a table when you should be in the workshop achieving something real. Models of the single tube amplifier stage should include an extremely low voltage generator producing output of x Vg with series resistance between the gene output and the anode terminal should be explained as equivalent models of the triode or pentode ot any other tube. Newbies NEED to know the very boring basics before thay can have any chance of understanding. Most don't have a clue what a voltage generator is, or what the dynamic anode resistance is at all!!! An interesting point. Do you think NFB101 should start with a statement of what knowledge is assumed along with pointers to references for those who don't have it? Exactly. NFB is a very tricky and foreign concept to many minds. Its no use taling about volts and amps to those who don't know what they are and how they relate to resistance in the form of Ohm's Laws. Newbie confusions are 90% due to very poor mental picturing of the very basic issues. Instead of making the effort to leaqrn, the silly newbie short cuts to human commonsense, and such simplistic thinking doesn't work with electronics very well. First come the concepts, then the math. NFB acts in an amp to force it to amplify the difference between an input signal and an output signal. Distortion at the output is amplified in such a way to oppose its own production, and people must see how to easily calculate from what they observe in a given amp after taking voltage measurements after calculating gain. Then in an amp with NFB and OLG of 100, and = 0.1, and with 0.1% of THD at 10Vrms output level, there will be THD at the output = 10 x 0.1/100 Vrms = 0.01Vrms. If = 0.1, then 0.1 x 0.001Vrms of distortion appears at the negative feedback terminal of the amp which is the second of the pair of input terminals able to be found on every amplifier. So, with OLG = 100, it only takes 10V / 100 of input sugnal between the two input terminals for output of 10V, so the open loop Vin input voltage = 0.1Vrms. The 0.001Vrms of distortion is also amplified 100 times by the OLG gain and so hence appears as 0.1V Dn at the output. But how can this be when we measured Dn = 0.01Vrms??????? It is because the open loop character of the amp tries to make 0.11Vrms of Dn, but the amplified distortion fed back of 0.1Vrms subtracts from the 0.11Vrms of Dn to leave the measured residue of 0.01Vrms. The action of distortion reduction occurs simultaneously with distoprtion creation by the amp without any NFB. The open loop BW and thus phase of the signals determines how effective this THD/IMD reduction by NFB actually is. Even without the official feedback/gain/bandwidth formulas, the above explains the essence of NFB application in all cases of simple series voltage NFB, and even in a cathode follower, which the newbie must come to understand as the most basic of all applications of series voltage NFB. They have to know why the words "series" and "voltage" are used. One reason is that the type of *LOOP* or global NFB used most is neither "shunt" nor "current". Electronics demands we have to consider more than one thing acting simultaneously, and we have to make fine distinctions. I welcome you to borrow whatever you need from http://www.turneraudio.com.au/tube-operation1.html and http://www.turneraudio.com.au/tube-operation3.html I don't have all the possible various feedback applications mentiuoned at my site. Thanks for the permission to use ingfo from your site. Over the last 2.5 years since I included the NFB descriptions and basic tube workings at my website, nobody has challenged me on the legitimacy. Let me know if you think I have made any mistakes. Patrick Turner. t is Cheers Ian |
#8
Posted to rec.audio.tubes
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NFB 101 Part Deux
Patrick Turner wrote:
Using a triangle pointing to the right to represent an amp with two inputs on the left vertical side and one output at the right point is the text book way to represent an amp so people do not have to keep in mind all the complex inner amp topology which distracts them from the basic idea. The same model can then be used for a tube amp or an opamp. I purposely avoided that because its common usage is to represent an amplifier with infinite gain, zero output resistance and infinite input impedance and as we both know, tubes only meet one of those criteria. I was trying to emphasize that tubes fall far short of this ideal which is why many of the op-amp simplifications just don't apply to tubes. But even with an opamp with huge open loop gains and supposedly huge Rin, the actual OLG and OL BW ( open loop bandwidth ) can be stated as easily as the BASIC OL BW of a tube amp. The calculations should always include a drawn model of the amp with whatever BASIC resistances/impedances which affect the aplication of NFB. I agree the triangle is in common usage. However, the diagram I used does follow the RDH one and to me rather neatly shows exactly what is meant by series applied NFB which I find hard to see in the triangle version but that's just me. Perhaps when I get to multi-stage tube circuits the triangle will be more appropriate, much as illustrated by your owm web site. snip Newbies NEED to know the very boring basics before thay can have any chance of understanding. Most don't have a clue what a voltage generator is, or what the dynamic anode resistance is at all!!! An interesting point. Do you think NFB101 should start with a statement of what knowledge is assumed along with pointers to references for those who don't have it? Exactly. NFB is a very tricky and foreign concept to many minds. Its no use taling about volts and amps to those who don't know what they are and how they relate to resistance in the form of Ohm's Laws. Newbie confusions are 90% due to very poor mental picturing of the very basic issues. Instead of making the effort to leaqrn, the silly newbie short cuts to human commonsense, and such simplistic thinking doesn't work with electronics very well. First come the concepts, then the math. OK, I'll include a 'you must be familiar with' bit at the start along with pointers to books & web sites with the basics. I'll include a link to your site if that's OK. Over the last 2.5 years since I included the NFB descriptions and basic tube workings at my website, nobody has challenged me on the legitimacy. Let me know if you think I have made any mistakes. The power stuff certainly saves me a lot of work especially as tube power amps are a complete unknown to me. Thanks for the input. P.S I have just been through the pdf and changed all the Bs to betas and ms to mus (can't work out how to get special characters in my mail app). Cheers Ian |
#9
Posted to rec.audio.tubes
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NFB 101 Part Deux
Ian Thompson-Bell wrote: Patrick Turner wrote: Using a triangle pointing to the right to represent an amp with two inputs on the left vertical side and one output at the right point is the text book way to represent an amp so people do not have to keep in mind all the complex inner amp topology which distracts them from the basic idea. The same model can then be used for a tube amp or an opamp. I purposely avoided that because its common usage is to represent an amplifier with infinite gain, zero output resistance and infinite input impedance and as we both know, tubes only meet one of those criteria. I was trying to emphasize that tubes fall far short of this ideal which is why many of the op-amp simplifications just don't apply to tubes. But even with an opamp with huge open loop gains and supposedly huge Rin, the actual OLG and OL BW ( open loop bandwidth ) can be stated as easily as the BASIC OL BW of a tube amp. The calculations should always include a drawn model of the amp with whatever BASIC resistances/impedances which affect the aplication of NFB. I agree the triangle is in common usage. However, the diagram I used does follow the RDH one and to me rather neatly shows exactly what is meant by series applied NFB which I find hard to see in the triangle version but that's just me. Perhaps when I get to multi-stage tube circuits the triangle will be more appropriate, much as illustrated by your owm web site. snip Newbies NEED to know the very boring basics before thay can have any chance of understanding. Most don't have a clue what a voltage generator is, or what the dynamic anode resistance is at all!!! An interesting point. Do you think NFB101 should start with a statement of what knowledge is assumed along with pointers to references for those who don't have it? Exactly. NFB is a very tricky and foreign concept to many minds. Its no use taling about volts and amps to those who don't know what they are and how they relate to resistance in the form of Ohm's Laws. Newbie confusions are 90% due to very poor mental picturing of the very basic issues. Instead of making the effort to leaqrn, the silly newbie short cuts to human commonsense, and such simplistic thinking doesn't work with electronics very well. First come the concepts, then the math. OK, I'll include a 'you must be familiar with' bit at the start along with pointers to books & web sites with the basics. I'll include a link to your site if that's OK. Over the last 2.5 years since I included the NFB descriptions and basic tube workings at my website, nobody has challenged me on the legitimacy. Let me know if you think I have made any mistakes. The power stuff certainly saves me a lot of work especially as tube power amps are a complete unknown to me. Thanks for the input. P.S I have just been through the pdf and changed all the Bs to betas and ms to mus (can't work out how to get special characters in my mail app). When doing plain text emails to the group or anyone else, I depress Alt while typing 2 3 0 for or mu when I release the Alt key. Alt and 2 2 5 gives , or beta. I used to use u and B for and and got pulled up about it. B is reserved for magnetic field strength, not the fraction fed back. Context makes it obvious though what id meant, but adherance to old conventions makes it easier when ppl read something elsewhere and they don't have to learn another language, or drive on the other side of the road. But I don't know what other typing tricks give what. Anyone like to post the list of possible Alt plus signs and figures????? Patrick Turner. Cheers Ian |
#10
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NFB 101 Part Deux
Patrick Turner wrote:
When doing plain text emails to the group or anyone else, I depress Alt while typing 2 3 0 for or mu when I release the Alt key. Alt and 2 2 5 gives , or beta. Unfortunately that does not seem to work for me. Anyone know how to do it in Thunderbird? Cheers Ian |
#11
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NFB 101 Part Deux
Ian Thompson-Bell wrote: Patrick Turner wrote: When doing plain text emails to the group or anyone else, I depress Alt while typing 2 3 0 for or mu when I release the Alt key. Alt and 2 2 5 gives , or beta. Unfortunately that does not seem to work for me. Anyone know how to do it in Thunderbird? It's not related to Thunderbird. It's how to generate 'alternate characters' generally in Windows but Patrick didn't explain it fully. Hold down the Alt key *and keep it held down*. Then press 2, 3 ,0 ON THE NUMERIC KEYPAD. Then release the Alt key. Should work on all PCs with Windows. Graham |
#12
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NFB 101 Part Deux
Eeyore wrote:
Ian Thompson-Bell wrote: Patrick Turner wrote: When doing plain text emails to the group or anyone else, I depress Alt while typing 2 3 0 for or mu when I release the Alt key. Alt and 2 2 5 gives , or beta. Unfortunately that does not seem to work for me. Anyone know how to do it in Thunderbird? It's not related to Thunderbird. It's how to generate 'alternate characters' generally in Windows but Patrick didn't explain it fully. Hold down the Alt key *and keep it held down*. Then press 2, 3 ,0 ON THE NUMERIC KEYPAD. Then release the Alt key. Should work on all PCs with Windows. Graham But I am not using windows, I am using Linux Cheers Ian |
#13
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NFB 101 Part Deux
Ian Thompson-Bell wrote: Eeyore wrote: Ian Thompson-Bell wrote: Patrick Turner wrote: When doing plain text emails to the group or anyone else, I depress Alt while typing 2 3 0 for or mu when I release the Alt key. Alt and 2 2 5 gives , or beta. Unfortunately that does not seem to work for me. Anyone know how to do it in Thunderbird? It's not related to Thunderbird. It's how to generate 'alternate characters' generally in Windows but Patrick didn't explain it fully. Hold down the Alt key *and keep it held down*. Then press 2, 3 ,0 ON THE NUMERIC KEYPAD. Then release the Alt key. Should work on all PCs with Windows. Graham But I am not using windows, I am using Linux Then it won't work ! I imagine there may be some equivalent way to do the same. Graham |
#14
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NFB 101 Part Deux
Eeyore wrote: Ian Thompson-Bell wrote: Patrick Turner wrote: When doing plain text emails to the group or anyone else, I depress Alt while typing 2 3 0 for or mu when I release the Alt key. Alt and 2 2 5 gives , or beta. Unfortunately that does not seem to work for me. Anyone know how to do it in Thunderbird? It's not related to Thunderbird. It's how to generate 'alternate characters' generally in Windows but Patrick didn't explain it fully. Hold down the Alt key *and keep it held down*. Then press 2, 3 ,0 ON THE NUMERIC KEYPAD. Then release the Alt key. Should work on all PCs with Windows. Graham Yes, that is correct, and if you typed 2 3 0 on the numbers near the letters, it won't go, and the numbers pad to the left has to be used. Funny thing, but I never ever use this number pad for anything else than for and . Patrick Turner. PS, And a happy St Pat's day to all o'yer. I heard St Patrick was a son of a Roman nobleman of Britain, before 400AD, and when Christianity had become the official church of Rome to replace the pagan faiths. If yer can't beat em, join em. Well now, that's what me muther told me today now. She says he wasn't even an Irishman. But me dear old dear has drifted a bit off the old faith, after reading lots of books. But what she didn't tell me was that 'tis said St Patrick had a whopper of a cock, and when he went to Ireland, and faced the wilderness, he raised his kilt and showed it to the Irish snakes, and they became so terrified at Paddy's snake they fled across the sea. No more snakes in Ireland after that. Patrick Turner. |
#15
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NFB 101 Part Deux
Ian Thompson-Bell wrote: Eeyore wrote: Ian Thompson-Bell wrote: Patrick Turner wrote: When doing plain text emails to the group or anyone else, I depress Alt while typing 2 3 0 for or mu when I release the Alt key. Alt and 2 2 5 gives , or beta. Unfortunately that does not seem to work for me. Anyone know how to do it in Thunderbird? It's not related to Thunderbird. It's how to generate 'alternate characters' generally in Windows but Patrick didn't explain it fully. Hold down the Alt key *and keep it held down*. Then press 2, 3 ,0 ON THE NUMERIC KEYPAD. Then release the Alt key. Should work on all PCs with Windows. Graham But I am not using windows, I am using Linux Cheers There must be a way to type greek letters used in science. Patrick Turner. Ian |
#16
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NFB 101 Part Deux
Hold down the Alt key *and keep it held down*.
Then press 2, 3 ,0 ON THE NUMERIC KEYPAD. Then release the Alt key. Should work on all PCs with Windows. Deeper than windows, goes back at least to MSDOS and maybe deeper than that. It's just ASCII code. A table of the extended ASCII set reveals all. Ian |
#17
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NFB 101 Part Deux
Patrick Turner wrote:
Eeyore wrote: Ian Thompson-Bell wrote: Patrick Turner wrote: When doing plain text emails to the group or anyone else, I depress Alt while typing 2 3 0 for or mu when I release the Alt key. Alt and 2 2 5 gives , or beta. Unfortunately that does not seem to work for me. Anyone know how to do it in Thunderbird? It's not related to Thunderbird. It's how to generate 'alternate characters' generally in Windows but Patrick didn't explain it fully. Hold down the Alt key *and keep it held down*. Then press 2, 3 ,0 ON THE NUMERIC KEYPAD. Then release the Alt key. Should work on all PCs with Windows. Graham Yes, that is correct, and if you typed 2 3 0 on the numbers near the letters, it won't go, and the numbers pad to the left has to be used. Funny thing, but I never ever use this number pad for anything else than for and . Er, my laptop does not have a separate numeric keypad - oops yes it does but they only work when NumLock is engaged - even then alt 230 does not work. I have asked on a Linux forum so maybe they'll know. CHeers Ian |
#18
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NFB 101 Part Deux
Patrick Turner wrote:
Ian Thompson-Bell wrote: Eeyore wrote: Ian Thompson-Bell wrote: Patrick Turner wrote: When doing plain text emails to the group or anyone else, I depress Alt while typing 2 3 0 for or mu when I release the Alt key. Alt and 2 2 5 gives , or beta. Unfortunately that does not seem to work for me. Anyone know how to do it in Thunderbird? It's not related to Thunderbird. It's how to generate 'alternate characters' generally in Windows but Patrick didn't explain it fully. Hold down the Alt key *and keep it held down*. Then press 2, 3 ,0 ON THE NUMERIC KEYPAD. Then release the Alt key. Should work on all PCs with Windows. Graham But I am not using windows, I am using Linux Cheers There must be a way to type greek letters used in science. Easy enough in a word processor but not is seems in the mail client. Cheers Ian |
#19
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NFB 101 Part Deux
-- Iain Aural perception is a skill that requires study and careful development over along period of time. Few have it as a natural gift. "Ian Thompson-Bell" wrote in message ... Patrick Turner wrote: Eeyore wrote: Ian Thompson-Bell wrote: Patrick Turner wrote: When doing plain text emails to the group or anyone else, I depress Alt while typing 2 3 0 for or mu when I release the Alt key. Alt and 2 2 5 gives , or beta. Unfortunately that does not seem to work for me. Anyone know how to do it in Thunderbird? It's not related to Thunderbird. It's how to generate 'alternate characters' generally in Windows but Patrick didn't explain it fully. Hold down the Alt key *and keep it held down*. Then press 2, 3 ,0 ON THE NUMERIC KEYPAD. Then release the Alt key. Should work on all PCs with Windows. Grahamo Yes, that is correct, and if you typed 2 3 0 on the numbers near the letters, it won't go, and the numbers pad to the left has to be used. Funny thing, but I never ever use this number pad for anything else than for and . Er, my laptop does not have a separate numeric keypad - oops yes it does but they only work when NumLock is engaged - even then alt 230 does not work. I have asked on a Linux forum so maybe they'll know. I use a Scandi keyboard. The character is marked on the keyboard and can be accessed by ALT-M. I cannot find the code for beta. Any ideas? Iain |
#20
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NFB 101 Part Deux
I think I make have cracked it, this should be beta and this mu
is Alt-Gr-s and is Alt-gr-m wher Alt-Gr is the the other alt key to the right of the space bar on my laptop and which is labeled Alt Gr. Cheers Ian |
#21
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NFB 101 Part Deux
"Ian Thompson-Bell" wrote in message ... I think I make have cracked it, this should be beta and this mu is Alt-Gr-s and is Alt-gr-m wher Alt-Gr is the the other alt key to the right of the space bar on my laptop and which is labeled Alt Gr. Hmm. can be found on my keyboard as AltGr-M and also as ALT 230 . I stilla kanna finda "beta" Iain |
#22
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NFB 101 Part Deux
"Ian Thompson-Bell" wrote in message ... I think I make have cracked it, this should be beta and this mu is Alt-Gr-s and is Alt-gr-m wher Alt-Gr is the the other alt key to the right of the space bar on my laptop and which is labeled Alt Gr. Hmm. can be found on my keyboard as AltGr-M and also as ALT 230 . I stilla kanna finda "beta" Iain |
#23
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NFB 101 Part Deux
flipper wrote:
On Mon, 17 Mar 2008 11:15:18 +0000, Ian Thompson-Bell wrote: Patrick Turner wrote: When doing plain text emails to the group or anyone else, I depress Alt while typing 2 3 0 for or mu when I release the Alt key. Alt and 2 2 5 gives , or beta. Unfortunately that does not seem to work for me. Anyone know how to do it in Thunderbird? Cheers Ian If it's the same as Seamonkey you can insert special characters from the menu "Insert -- Characters and Symbols." You get a dialogue box with 'category selection' and drop down selection of the symbol (from that category). Can't find anything like that in Thunderbird. Cheers Ian |
#24
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NFB 101 Part Deux
In article i,
"Iain Churches" wrote: "Ian Thompson-Bell" wrote in message ... I think I make have cracked it, this should be beta and this mu is Alt-Gr-s and is Alt-gr-m wher Alt-Gr is the the other alt key to the right of the space bar on my laptop and which is labeled Alt Gr. Hmm. can be found on my keyboard as AltGr-M and also as ALT 230 . I stilla kanna finda "beta" Is this "" beta? On my keyboard it is alt s, I wonder if my newsreader will leave it alone. Regards, John Byrns -- Surf my web pages at, http://fmamradios.com/ |
#25
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NFB 101 Part Deux
"John Byrns" wrote in message ... In article i, "Iain Churches" wrote: "Ian Thompson-Bell" wrote in message ... I think I make have cracked it, this should be beta and this mu is Alt-Gr-s and is Alt-gr-m wher Alt-Gr is the the other alt key to the right of the space bar on my laptop and which is labeled Alt Gr. Hmm. can be found on my keyboard as AltGr-M and also as ALT 230 . I stilla kanna finda "beta" Is this "" beta? On my keyboard it is alt s, I wonder if my newsreader will leave it alone. In outlook express, alt s sends the message you're trying to compose. ;-( Fred Regards, John Byrns -- Surf my web pages at, http://fmamradios.com/ |
#26
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NFB 101 Part Deux
Ian wrote:
Sorry it has been a while coming but I have just finished part two of NFB 101. I found I could not describe it properly without diagrams and proper equations so I had to resort to using a word processor and converting the result into a pdf, all of which took time. So point your browser he http://www.ianbell.ukfsn.org/data/nfb101.pdf to download it. Certainly got everyone talking about feedback... What was the point? Good for DC, but very misleading, IMO, to depict a block with more than one input. Find someone who claims to learn from this kind of stuff, and test him. It's easy to foster delusions of knowledge. Ppl who to want to teach would do well to find out how. It's a skilled profession, doncha know. Sorry to be a wet blanket. Ian |
#27
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NFB 101 Part Deux
"John Byrns" wrote in message ... In article i, "Iain Churches" wrote: "Ian Thompson-Bell" wrote in message ... I think I make have cracked it, this should be beta and this mu is Alt-Gr-s and is Alt-gr-m wher Alt-Gr is the the other alt key to the right of the space bar on my laptop and which is labeled Alt Gr. Hmm. can be found on my keyboard as AltGr-M and also as ALT 230 . I stilla kanna finda "beta" Is this "" beta? On my keyboard it is alt s, I wonder if my newsreader will leave it alone. Yes. That works. Alt-s on Outlook Express with my Scandi keyboard sends the messsage just as Control-s does. I still cannot find "beta" perhaps I shall need to cut and paste it from one of your posts:-) Iain |
#28
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NFB 101 Part Deux
Ian Iveson wrote: Ian wrote: Sorry it has been a while coming but I have just finished part two of NFB 101. I found I could not describe it properly without diagrams and proper equations so I had to resort to using a word processor and converting the result into a pdf, all of which took time. So point your browser he http://www.ianbell.ukfsn.org/data/nfb101.pdf to download it. Certainly got everyone talking about feedback... What was the point? Good for DC, but very misleading, IMO, to depict a block with more than one input. Find someone who claims to learn from this kind of stuff, and test him. It's easy to foster delusions of knowledge. Ppl who to want to teach would do well to find out how. It's a skilled profession, doncha know. Sorry to be a wet blanket. I think you really delight in being a soggy cold dripping wet blanket sometimes. ALL amplifiers have TWO input and TWO output terminals. The majority of amplifiers are set up so the input from an external source is brought to the amp between 0V and ONE of the two inputs. But an input transformer can act so the pair of input terminals are floating and have no direct connection to 0V. The OTHER remaining input is sometimes connected to 0V. The output signal is often but not always put out as acting between TWO live output terminals, and with one of them connected to 0V. The output can also float with both terminals un-referenced to 0V, like the input, by means of an OPT. Excactly what set up one has for analysis can be simply depicted with symbols rather than labour with all the details of internal circuitry. It makes NFB application easier to understand. Patrick Turner. Ian |
#29
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NFB 101 Part Deux
Ian Iveson wrote: Hold down the Alt key *and keep it held down*. Then press 2, 3 ,0 ON THE NUMERIC KEYPAD. Then release the Alt key. Should work on all PCs with Windows. Deeper than windows, goes back at least to MSDOS and maybe deeper than that. It's just ASCII code. A table of the extended ASCII set reveals all. Ian yeah, ASCII is viewable at http://www.asciitable.com/ Alt plus 230 gives , Alt plus 225 gives , Alt plus 234 should give the omega sign, but gives only 0????? Alt plus 237 should give theta but gives f, and plus 232 should give a similar larger theta but gives only F. Alt, 168 = , Alt 233 gives T, not a circle with dot in the middle. So not much good eh? Patrick Turner. |
#30
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NFB 101 Part Deux
-- Iain Aural perception is a skill that requires study and careful development over along period of time. Few have it as a natural gift. "flipper" wrote in message ... On Tue, 18 Mar 2008 09:14:27 +0200, "Iain Churches" wrote: "John Byrns" wrote in message ... In article i, "Iain Churches" wrote: "Ian Thompson-Bell" wrote in message ... I think I make have cracked it, this should be beta and this mu is Alt-Gr-s and is Alt-gr-m wher Alt-Gr is the the other alt key to the right of the space bar on my laptop and which is labeled Alt Gr. Hmm. can be found on my keyboard as AltGr-M and also as ALT 230 . I stilla kanna finda "beta" Is this "" beta? On my keyboard it is alt s, I wonder if my newsreader will leave it alone. Yes. That works. Alt-s on Outlook Express with my Scandi keyboard sends the messsage just as Control-s does. I still cannot find "beta" perhaps I shall need to cut and paste it from one of your posts:-) Iain Hold ALT, on numeric keypad press 2 2 5, release ALT. Hooray! Thanks illion:-) Iain |
#31
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NFB 101 Part Deux
Iain Churches wrote:
"Ian Thompson-Bell" wrote in message ... I think I make have cracked it, this should be beta and this mu is Alt-Gr-s and is Alt-gr-m wher Alt-Gr is the the other alt key to the right of the space bar on my laptop and which is labeled Alt Gr. Hmm. can be found on my keyboard as AltGr-M and also as ALT 230 . I stilla kanna finda "beta" Iain what do you get for Alt-Gr-S ?? Cheers Ian |
#32
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NFB 101 Part Deux
John Byrns wrote:
Is this "" beta? On my keyboard it is alt s, I wonder if my newsreader will leave it alone. Still looks like a at this end too. Cheers Ian |
#33
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NFB 101 Part Deux
Iain Churches wrote: -- Iain Aural perception is a skill that requires study and careful development over along period of time. Few have it as a natural gift. "flipper" wrote in message ... On Tue, 18 Mar 2008 09:14:27 +0200, "Iain Churches" wrote: "John Byrns" wrote in message ... In article i, "Iain Churches" wrote: "Ian Thompson-Bell" wrote in message ... I think I make have cracked it, this should be beta and this mu is Alt-Gr-s and is Alt-gr-m wher Alt-Gr is the the other alt key to the right of the space bar on my laptop and which is labeled Alt Gr. Hmm. can be found on my keyboard as AltGr-M and also as ALT 230 . I stilla kanna finda "beta" Is this "" beta? On my keyboard it is alt s, I wonder if my newsreader will leave it alone. Yes. That works. Alt-s on Outlook Express with my Scandi keyboard sends the messsage just as Control-s does. I still cannot find "beta" perhaps I shall need to cut and paste it from one of your posts:-) Iain Hold ALT, on numeric keypad press 2 2 5, release ALT. Hooray! Thanks illion:-) Iain Thanks llion, and illion. But thats all the greek I can find with alt XXX presses. I've seen the ascii list and what's supposed to come out with different number pad numbers does not arrive. So its sorta works, and sorta don't work.... Patrick Turner. |
#34
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NFB 101 Part Deux
Ian Iveson wrote:
Ian wrote: Sorry it has been a while coming but I have just finished part two of NFB 101. I found I could not describe it properly without diagrams and proper equations so I had to resort to using a word processor and converting the result into a pdf, all of which took time. So point your browser he http://www.ianbell.ukfsn.org/data/nfb101.pdf to download it. Certainly got everyone talking about feedback... What was the point? It was suggested that documenting the basics as they apply to tubes would be a good idea and I sort volunteered to do it. Good for DC, Of course. It is a work in progress. You have to establish the basics before moving on to the hard bits. but very misleading, IMO, to depict a block with more than one input. Please explain how that is misleading. Find someone who claims to learn from this kind of stuff, and test him. It's easy to foster delusions of knowledge. Time only will tell. Once it is complete it will either be slated or revered, probably both. I am happy to put the effort in. Ppl who to want to teach would do well to find out how. It's a skilled profession, doncha know. So is electronics design of any sort, but there's loads of amateurs on this group and I think it is beneficial to try to explain things that are relevant to tubes design. There are plenty of web resources on basic tube theory but little on the depths of tube NFB. Sorry to be a wet blanket. No problem. If you have any constructive criticism I'll be glad to hear. Perhapss you would like to contribute. Cheers Ian |
#35
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NFB 101 Part Deux
flipper wrote:
Ian If it's the same as Seamonkey you can insert special characters from the menu "Insert -- Characters and Symbols." You get a dialogue box with 'category selection' and drop down selection of the symbol (from that category). Can't find anything like that in Thunderbird. Hmm. Well, I suppose it figures they'd make two products doing the 'same thing' different. Cheers Ian I just discovered there's a char map application under Accessories in Ubuntu so here's a ß and here's a different one β and here's a mu μ. Cheers Ian |
#36
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NFB 101 Part Deux
"Patrick Turner" wrote in message ... Iain Churches wrote: Hooray! Thanks illion:-) Iain Thanks llion, and illion. But thats all the greek I can find with alt XXX presses. I've seen the ascii list and what's supposed to come out with different number pad numbers does not arrive. So its sorta works, and sorta don't work.... Yes. That's what I find also. Iain |
#37
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NFB 101 Part Deux
"Ian Thompson-Bell" wrote in message ... Iain Churches wrote: "Ian Thompson-Bell" wrote in message ... I think I make have cracked it, this should be beta and this mu is Alt-Gr-s and is Alt-gr-m wher Alt-Gr is the the other alt key to the right of the space bar on my laptop and which is labeled Alt Gr. Hmm. can be found on my keyboard as AltGr-M and also as ALT 230 . I stilla kanna finda "beta" Iain what do you get for Alt-Gr-S ?? Nothing at all. There are only two Alt-Gr combinations that work: Alt-Gr E gives me the Euro sign ? and Alt-Gr M gives me And Alt-S send the message. But Alt-225 give me :-) I am happy with that. Iain |
#38
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NFB 101 Part Deux
In article ,
Patrick Turner wrote: Iain Churches wrote: -- Iain Aural perception is a skill that requires study and careful development over along period of time. Few have it as a natural gift. "flipper" wrote in message ... On Tue, 18 Mar 2008 09:14:27 +0200, "Iain Churches" wrote: "John Byrns" wrote in message ... In article i, "Iain Churches" wrote: "Ian Thompson-Bell" wrote in message ... I think I make have cracked it, this should be beta and this mu is Alt-Gr-s and is Alt-gr-m wher Alt-Gr is the the other alt key to the right of the space bar on my laptop and which is labeled Alt Gr. Hmm. can be found on my keyboard as AltGr-M and also as ALT 230 . I stilla kanna finda "beta" Is this "" beta? On my keyboard it is alt s, I wonder if my newsreader will leave it alone. Yes. That works. Alt-s on Outlook Express with my Scandi keyboard sends the messsage just as Control-s does. I still cannot find "beta" perhaps I shall need to cut and paste it from one of your posts:-) Iain Hold ALT, on numeric keypad press 2 2 5, release ALT. Hooray! Thanks illion:-) Iain Thanks llion, and illion. But thats all the greek I can find with alt XXX presses. I've seen the ascii list and what's supposed to come out with different number pad numbers does not arrive. So its sorta works, and sorta don't work.... I get the Greek characters shown in the second line below from my keyboard by holding down the "alt" key and pressing the key shown in the first line. a b c d e f g h i j k l m n o p q r s t u v w x y z Well I guess they all aren't Greek, and I had to leave out the characters corresponding to the letters e, i, n, & u because they seem to cause side effects in my newsreader. Regards, John Byrns -- Surf my web pages at, http://fmamradios.com/ |
#39
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NFB 101 Part Deux
"John Byrns" wrote in message ... In article , Patrick Turner wrote: Iain Churches wrote: -- Iain Aural perception is a skill that requires study and careful development over along period of time. Few have it as a natural gift. "flipper" wrote in message ... On Tue, 18 Mar 2008 09:14:27 +0200, "Iain Churches" wrote: "John Byrns" wrote in message ... In article i, "Iain Churches" wrote: "Ian Thompson-Bell" wrote in message ... I think I make have cracked it, this should be beta and this mu is Alt-Gr-s and is Alt-gr-m wher Alt-Gr is the the other alt key to the right of the space bar on my laptop and which is labeled Alt Gr. Hmm. can be found on my keyboard as AltGr-M and also as ALT 230 . I stilla kanna finda "beta" Is this "" beta? On my keyboard it is alt s, I wonder if my newsreader will leave it alone. Yes. That works. Alt-s on Outlook Express with my Scandi keyboard sends the messsage just as Control-s does. I still cannot find "beta" perhaps I shall need to cut and paste it from one of your posts:-) Iain Hold ALT, on numeric keypad press 2 2 5, release ALT. Hooray! Thanks illion:-) Iain Thanks llion, and illion. But thats all the greek I can find with alt XXX presses. I've seen the ascii list and what's supposed to come out with different number pad numbers does not arrive. So its sorta works, and sorta don't work.... I get the Greek characters shown in the second line below from my keyboard by holding down the "alt" key and pressing the key shown in the first line. a b c d e f g h i j k l m n o p q r s t u v w x y z ? Y T s ^ . ? ? Well I guess they all aren't Greek Indeed:-) The first is the Swedish "o" (why then is it an "a" you might ask! I get nothing with the alt key esxcept shortcuts to the newsreader commands. But with Alt/Gr I get: Scandi a b c d e f g h i j k l m n o p q r s t u v w x y z ? UK a b c d e f g h i j k l m n o p q r s t u v w x y z Most curious Iain |
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NFB 101 Part Deux
Iain Churches wrote:
"John Byrns" wrote in message ... In article , Patrick Turner wrote: Iain Churches wrote: -- Iain Aural perception is a skill that requires study and careful development over along period of time. Few have it as a natural gift. "flipper" wrote in message ... On Tue, 18 Mar 2008 09:14:27 +0200, "Iain Churches" wrote: "John Byrns" wrote in message ... In article i, "Iain Churches" wrote: "Ian Thompson-Bell" wrote in message ... I think I make have cracked it, this should be beta ß and this mu µ ß is Alt-Gr-s and µ is Alt-gr-m wher Alt-Gr is the the other alt key to the right of the space bar on my laptop and which is labeled Alt Gr. Hmm. µ can be found on my keyboard as AltGr-M µµµµµ and also as ALT 230 µ. I stilla kanna finda "beta" Is this "ß" beta? On my keyboard it is alt s, I wonder if my newsreader will leave it alone. Yes. That works. Alt-s on Outlook Express with my Scandi keyboard sends the messsage just as Control-s does. I still cannot find "beta" perhaps I shall need to cut and paste it from one of your posts:-) Iain Hold ALT, on numeric keypad press 2 2 5, release ALT. Hooray! ßßßßß Thanks ßillion:-) Iain ß Thanks µllion, and ßillion. But thats all the greek I can find with alt XXX presses. I've seen the ascii list and what's supposed to come out with different number pad numbers does not arrive. So its sorta works, and sorta don't work.... I get the Greek characters shown in the second line below from my keyboard by holding down the "alt" key and pressing the key shown in the first line. a b c d e f g h i j k l m n o p q r s t u v w x y z å ? ç Y © T s ¬ µ ø ¼ ¦ ® ß Ý ^ . ? ¥ ? Well I guess they all aren't Greek Indeed:-) The first is the Swedish "o" (why then is it an "a" you might ask! I get nothing with the alt key esxcept shortcuts to the newsreader commands. But with Alt/Gr I get: Scandi a b c d e f g h i j k l m n o p q r s t u v w x y z ? µ UK a b c d e f g h i j k l m n o p q r s t u v w x y z á é * ó ú Most curious Iain With Alt-Gr I get abcdefghijklmnopqrstuvwxyz æ¢ðeđŋħjĸłµnøþ@¶ßŧł» « and with the numbers I get 1234567890 ¹²³½¾{[]} Cheers Ian |
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