|
ssb, linears, and caps
I noticed that a lot of high end auto audio systems use a capacitor in
series with the main power lead to the amplifies so the amp hits harder. Could this same principle be applied to ssb, I think it can. place a 1 farad audio cap inline with the power lead to say a Texas star dx1600 and you run the rig on ssb the cap will discharge under peak load giving you a higher average output. Any comments? (and I mean REAL comments) |
On Mon, 8 Dec 2003 03:23:00 -0600, "Dr. Death"
wrote: I noticed that a lot of high end auto audio systems use a capacitor in series with the main power lead to the amplifies so the amp hits harder. Could this same principle be applied to ssb, I think it can. place a 1 farad audio cap inline with the power lead to say a Texas star dx1600 and you run the rig on ssb the cap will discharge under peak load giving you a higher average output. Any comments? (and I mean REAL comments) There's not even close to enough stored energy in large capacitor to make and peak voltage difference that would translate into any perceivable gain. P.S. the cap is in parallel |
|
"Dr. Death", It wouldn't help at all, especially if the capacitor is in series with the power line to the amplifier. 'Doc |
In , "Dr. Death"
wrote: I noticed that a lot of high end auto audio systems use a capacitor in series with the main power lead to the amplifies so the amp hits harder. Could this same principle be applied to ssb, I think it can. place a 1 farad audio cap inline with the power lead to say a Texas star dx1600 and you run the rig on ssb the cap will discharge under peak load giving you a higher average output. Any comments? (and I mean REAL comments) Even though you are a troll, you actually raise a good point here. Now I'm assuming you meant that the capacitor is connected in parallel with the power supply leads, because if it were connected in series you would get no power. In an SSB amp the RF power follows the audio, and will therefore have a current draw that varies at audio frequencies. A capacitor placed across the power leads of the amp, when combined with the inherent resistance of the wires from the battery, creates a simple low-pass filter which will help smooth out those 'audio' peaks. The bigger the amp, the bigger the cap. And keep the leads from the amp to the cap as short as possible. BTW, this type of filter won't do much in AM service since the current drawn by the amp in AM is fairly steady (at least it -should- be, i.e, it's not amplifying a signal loaded with overmodulation and 'swang'). But it -will- filter out noise from the power supply. A word about those 'moster caps' for audio amps: Most of them have a high equivalent series resistance (ESR) which defeats the purpose of using them. They behave more like a rechargeable battery than a capacitor. Locate your local computer junkyard and get some of those big electrolytics from the mainframe power supplies. Typically, just one 100,000 uFd aluminum electrolytic has a lower ESR than a 1.0 farad 'monster' cap. Also remember that you can reduce the ESR by putting capacitors in parallel. Ten 10,000 uFd caps in parallel will have a much better ESR, and therefore much better filtering ability, than one 100,000 uFd capacitor of the same type, even though the total mFd value is the same. ============= "...but I admitted I was wrong, Like a man! Something you and QRM have a problem with. You guys are wrong and you both know it and are both too small to admit it." ---- Twistedhed ---- ============= -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
no...on car audio its in series with the positive feed
wrote in message ... On Mon, 8 Dec 2003 03:23:00 -0600, "Dr. Death" wrote: I noticed that a lot of high end auto audio systems use a capacitor in series with the main power lead to the amplifies so the amp hits harder. Could this same principle be applied to ssb, I think it can. place a 1 farad audio cap inline with the power lead to say a Texas star dx1600 and you run the rig on ssb the cap will discharge under peak load giving you a higher average output. Any comments? (and I mean REAL comments) There's not even close to enough stored energy in large capacitor to make and peak voltage difference that would translate into any perceivable gain. P.S. the cap is in parallel |
"Frank Gilliland" wrote in message ... In , "Dr. Death" wrote: I noticed that a lot of high end auto audio systems use a capacitor in series with the main power lead to the amplifies so the amp hits harder. Could this same principle be applied to ssb, I think it can. place a 1 farad audio cap inline with the power lead to say a Texas star dx1600 and you run the rig on ssb the cap will discharge under peak load giving you a higher average output. Any comments? (and I mean REAL comments) Even though you are a troll, you actually raise a good point here. Now I'm troll????? you don't even know me. assuming you meant that the capacitor is connected in parallel with the power bad on my part, i thought it was in series butv after closer investigation i found they were grounding it with the mounting bracket supply leads, because if it were connected in series you would get no power. In an SSB amp the RF power follows the audio, and will therefore have a current draw that varies at audio frequencies. A capacitor placed across the power leads of the amp, when combined with the inherent resistance of the wires from the battery, creates a simple low-pass filter which will help smooth out those 'audio' peaks. The bigger the amp, the bigger the cap. And keep the leads from the amp to the cap as short as possible. So you agree, it would work for ssb BTW, this type of filter won't do much in AM service since the current drawn by the amp in AM is fairly steady (at least it -should- be, i.e, it's not amplifying a signal loaded with overmodulation and 'swang'). But it -will- filter out noise from the power supply. A word about those 'moster caps' for audio amps: Most of them have a high equivalent series resistance (ESR) which defeats the purpose of using them. They behave more like a rechargeable battery than a capacitor. Locate your local computer junkyard and get some of those big electrolytics from the mainframe power supplies. Typically, just one 100,000 uFd aluminum electrolytic has a lower ESR than a 1.0 farad 'monster' cap. Also remember that you can reduce the ESR by putting capacitors in parallel. Ten 10,000 uFd caps in parallel will have a much better ESR, and therefore much better filtering ability, than one 100,000 uFd capacitor of the same type, even though the total mFd value is the same. ============= "...but I admitted I was wrong, Like a man! Something you and QRM have a problem with. You guys are wrong and you both know it and are both too small to admit it." ---- Twistedhed ---- ============= -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
In , "Dr. Death"
wrote: snip So you agree, it would work for ssb I agree that adding a cap across the power leads will help keep the peaks up, and that's assuming the amp isn't clipping on the peaks. IOW, it should improve the audio quality when using a less-than-perfect power supply, just as if it were an audio amp. What it -won't- do is improve your average output power by any significant margin. -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
if your peaks are up that equates to higher (but probably not much like you
said) average output. BUT, you brought up a good point about the clipping "Frank Gilliland" wrote in message ... In , "Dr. Death" wrote: snip So you agree, it would work for ssb I agree that adding a cap across the power leads will help keep the peaks up, and that's assuming the amp isn't clipping on the peaks. IOW, it should improve the audio quality when using a less-than-perfect power supply, just as if it were an audio amp. What it -won't- do is improve your average output power by any significant margin. -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
Dr. Death wrote:
no...on car audio its in series with the positive feed I don't think a capacitor in series with the DC power lead of a car audio system is going to work very well. wrote in message ... On Mon, 8 Dec 2003 03:23:00 -0600, "Dr. Death" wrote: I noticed that a lot of high end auto audio systems use a capacitor in series with the main power lead to the amplifies so the amp hits harder. This is more audiophool nonsense than anything else. |
I have used the BIG caps as used on the audio amps on my RF power amp and
it did help on the current spikes that was needed on SSB peaks. Without the Cap, the voltage could drop to 10.5 volts on current peaks measured at the amp, now it might go to 12 - 12.5 volts only rising to the supplied 13.8 volts in the system. It help to reduce the headlights flicker at night also. Just type in FARAD in e-bay search under car stereo. The caps can be dangerous when charged up . They can discharge VERY high amps if shorted out as their ESR is very low. 1- 30 Farads can be found, and they are not cheap either. I have seen a bank of them even crank over a 8 cylinder engine. Try that with 100,00 uF Cap. "Dr. Death" wrote in message ... if your peaks are up that equates to higher (but probably not much like you said) average output. BUT, you brought up a good point about the clipping "Frank Gilliland" wrote in message ... In , "Dr. Death" wrote: snip So you agree, it would work for ssb I agree that adding a cap across the power leads will help keep the peaks up, and that's assuming the amp isn't clipping on the peaks. IOW, it should improve the audio quality when using a less-than-perfect power supply, just as if it were an audio amp. What it -won't- do is improve your average output power by any significant margin. -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
In pP6Bb.465454$HS4.3620546@attbi_s01, "MasterCBer" wrote:
I have used the BIG caps as used on the audio amps on my RF power amp and it did help on the current spikes that was needed on SSB peaks. Without the Cap, the voltage could drop to 10.5 volts on current peaks measured at the amp, now it might go to 12 - 12.5 volts only rising to the supplied 13.8 volts in the system. It help to reduce the headlights flicker at night also. Just type in FARAD in e-bay search under car stereo. The caps can be dangerous when charged up . They can discharge VERY high amps if shorted out as their ESR is very low. 1- 30 Farads can be found, and they are not cheap either. I have seen a bank of them even crank over a 8 cylinder engine. Try that with 100,00 uF Cap. There's that "more power" attitude that drives an amp junkie's cravings. You need to learn what ESR is and how different it is for different types of capacitors (and batteries, too). For example, I have seen a car battery turn over an 8 cylinder engine, but that doesn't mean it has a low ESR. It just means that it can hold a big charge and has almost nothing to do with ESR. When all you want to do is to keep the peaks up in an SSB linear you don't need a charge so large that it will turn over an engine. That's called "overkill". ============= "...but I admitted I was wrong, Like a man! Something you and QRM have a problem with. You guys are wrong and you both know it and are both too small to admit it." ---- Twistedhed ---- ============= -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
"Dr. Death", Using a very large capacitor to keep the instantanious voltage from dropping very much certainly will work. The question is, how much benefit is going to be realized from that? The answer is, not very much. Now, balance that 'not very much' with the cost of those very large capacitors and draw your own conclusions. Personally, I think it's a waste of time, just isn't worth it. It usually means that you're trying to 'squeeze' more out of something than it was designed to do to start with, which is a kinda silly thing to do. If you want to try it, then have at it. I'd rather waste my money on other things... 'Doc |
On Mon, 8 Dec 2003 03:23:00 -0600, "Dr. Death"
wrote: I noticed that a lot of high end auto audio systems use a capacitor in series with the main power lead to the amplifies so the amp hits harder. Could this same principle be applied to ssb, I think it can. place a 1 farad audio cap inline with the power lead to say a Texas star dx1600 and you run the rig on ssb the cap will discharge under peak load giving you a higher average output. Any comments? (and I mean REAL comments) A one farad capacitor can only supply one amp for one second at one volt. Hardly worth the expense. It can only prevent a voltage drop on the first few peaks of a SSB modulated signal. It's usefulness would be almost totally drained after speaking just one appropriate word, pointless. |
actually it was just food for thought, with all the flaming going on I
thought I would introduce a subject that would produce more thinking than fighting. "'Doc" wrote in message ... "Dr. Death", Using a very large capacitor to keep the instantanious voltage from dropping very much certainly will work. The question is, how much benefit is going to be realized from that? The answer is, not very much. Now, balance that 'not very much' with the cost of those very large capacitors and draw your own conclusions. Personally, I think it's a waste of time, just isn't worth it. It usually means that you're trying to 'squeeze' more out of something than it was designed to do to start with, which is a kinda silly thing to do. If you want to try it, then have at it. I'd rather waste my money on other things... 'Doc |
Well lets see here DOC and Frank
Have you tried a Large farad cap on your amp? I thought not. So unless you have then don't cut it. Frank you need to learn what ESR is you ****en dum ass. These cap have a very LOW ESR as I said in my first post I or do you not read very well. Doc , it works, and you know it could unless your a Dumass also. so why put your little ****ty wisdom comments in Sure its costs money, but to me running several alternators and a big amp just to say Audio is a waste of money to me. We all have our quirks. Why do CBERs spend good money just to raise the power out on a 4 watt rig to 7 watts and think its walking the dog, cant tell it on the receiving end. O well beleave what you want. He asked a question and I gave a good answer, it works. Then here comes all the so called Brains on this group. Hell I dough if they really do anything with there's, just sent on their ass and tell every one else how smart they think they really are . SO called DOC is really a flunky, and Frank hell he must work for some portal potty outfit. Dam It would be nice if they could just give a answer without trying to act as if they are the only ones in the world with knowledge. **** them two. Frank go and get one of those caps there are very LOW "Frank Gilliland" wrote in message ... In , wrote: On Mon, 8 Dec 2003 03:23:00 -0600, "Dr. Death" wrote: I noticed that a lot of high end auto audio systems use a capacitor in series with the main power lead to the amplifies so the amp hits harder. Could this same principle be applied to ssb, I think it can. place a 1 farad audio cap inline with the power lead to say a Texas star dx1600 and you run the rig on ssb the cap will discharge under peak load giving you a higher average output. Any comments? (and I mean REAL comments) A one farad capacitor can only supply one amp for one second at one volt. Hardly worth the expense. It can only prevent a voltage drop on the first few peaks of a SSB modulated signal. It's usefulness would be almost totally drained after speaking just one appropriate word, pointless. Then there is not much point in using them in any kind of DC power supply, is there? Of course there is. Do the math, Tnom: A good car battery has, on the average, an source impedance of around 0.01 ohms (dropping 1 volt per 100 amps, which is a darn good battery). Ten feet of #8 AWG has a DC resistance of 0.0063 ohms, and we'll just assume that the negative lead is grounded at 0 ohms. So the total source impedance at the input of the amp is 0.0163 ohms. Now take an amp that can do 500 watts PEP. Assuming 50% efficiency, that means it can draw a maximum of 79.4 amps @ 12.6 volts. But since the source impedance is 0.0163 ohms, the voltage is going to drop 1.3 volts on the peaks, reducing the peak output by 50 watts or more. This is a type of soft-clipping and can result in some significant AF -and- RF distortion. And that's not considering the temperature coefficient of copper, which shows more resistance as it warms up from carrying lots of current, making the situation worse. Adding caps at the power input leads of the amp can significantly reduce the source impedance of the power supply. It -can't- provide more power than the supply is capable of providing, but it -can- smooth the voltage ripple just like in any other type of power supply. And what if the vehicle is running? Do the math: If you have a 100 amp alternator (at 13.8 volts), it has a source impedance of .138 ohms, which is significantly higher than the battery, so it's not going to be much help. In fact, because it's going to be so heavily loaded, it's going to introduce some ripple into the power lines, ripple that can be reduced by using caps at the input of the amp. How much capacitance is needed? There is no easy equation. There are a number of factors, such as the source resistance of the battery and alternator, resistance of the wire, ESR of the capacitors, average modulation percentage, PEP watts, etc, etc. Because of the very low impedance required by the amp, low ESR is paramount. Despite the advertised claims, the 'monster' caps usually have an ESR of several ohms, much higher than is usable. Computer-grade electrolytics have a much lower ESR. Using many smaller caps in parallel is better than one big cap because the ESR is much lower. Those are just a few things to consider. But the general rule is to keep adding caps until they no longer make any improvement. I'm really suprised, Tnom. After all the times you have shot your mouth off and been proven wrong on technical topics, you -still- haven't learned to think before you speak. Maybe next time. ============= "...but I admitted I was wrong, Like a man! Something you and QRM have a problem with. You guys are wrong and you both know it and are both too small to admit it." ---- Twistedhed ---- ============= -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
"Dr. Death", Good idea. 'Doc |
snip
A one farad capacitor can only supply one amp for one second at one volt. Hardly worth the expense. It can only prevent a voltage drop on the first few peaks of a SSB modulated signal. It's usefulness would be almost totally drained after speaking just one appropriate word, pointless. Then there is not much point in using them in any kind of DC power supply, is there? Of course there is. Do the math, Tnom: Oranges and apples............... P.S. you are a idiot for even equating the two A good car battery has, on the average, an source impedance of around 0.01 ohms (dropping 1 volt per 100 amps, which is a darn good battery). Ten feet of #8 AWG has a DC resistance of 0.0063 ohms, and we'll just assume that the negative lead is grounded at 0 ohms. So the total source impedance at the input of the amp is 0.0163 ohms. Now take an amp that can do 500 watts PEP. Assuming 50% efficiency, that means it can draw a maximum of 79.4 amps @ 12.6 volts. But since the source impedance is 0.0163 ohms, the voltage is going to drop 1.3 volts on the peaks, reducing the peak output by 50 watts or more. This is a type of soft-clipping and can result in some significant AF -and- RF distortion. And that's not considering the temperature coefficient of copper, which shows more resistance as it warms up from carrying lots of current, making the situation worse. Adding caps at the power input leads of the amp can significantly reduce the source impedance of the power supply. It -can't- provide more power than the supply is capable of providing, But for how long........."Do the math" but it -can- smooth the voltage ripple just like in any other type of power supply. And what if the vehicle is running? Do the math: If you have a 100 amp alternator (at 13.8 volts), it has a source impedance of .138 ohms, which is significantly higher than the battery, so it's not going to be much help. In fact, because it's going to be so heavily loaded, it's going to introduce some ripple into the power lines, ripple that can be reduced by using caps at the input of the amp. How much capacitance is needed? There is no easy equation. There are a number of factors, such as the source resistance of the battery and alternator, resistance of the wire, ESR of the capacitors, average modulation percentage, PEP watts, etc, etc. Because of the very low impedance required by the amp, low ESR is paramount. Despite the advertised claims, the 'monster' caps usually have an ESR of several ohms, much higher than is usable. Computer-grade electrolytics have a much lower ESR. Using many smaller caps in parallel is better than one big cap because the ESR is much lower. Those are just a few things to consider. But the general rule is to keep adding caps until they no longer make any improvement. I'm really suprised, Tnom. After all the times you have shot your mouth off and been proven wrong on technical topics, you -still- haven't learned to think before you speak. Maybe next time. One thing I am not surprised at........You will ignore the facts, like you normally do to flame the group or express your pseudo theory. Yeah...Right, A few farads will make a justifiable difference. You're to funny. |
In 9McBb.1407$8y1.13274@attbi_s52, "MasterCBer" wrote:
Well lets see here DOC and Frank Have you tried a Large farad cap on your amp? I use caps on just about everything mobile. They work great to get the low-end from an audio amp. No, I don't run an RF amp, base or mobile. Yes, I have intalled a few; and yes, they do run better with a big cap on the power leads. By 'better' I mean that the audio is cleaner and IMD is reduced. I thought not. No you didn't. So unless you have then don't cut it. Frank you need to learn what ESR is you ****en dum ass. These cap have a very LOW ESR as I said in my first post I or do you not read very well. From Cornell Dubilier: 381LX473M016A452 47000 uFd @ 16 VDC 0.017 ohms @ 120 Hz 0.013 ohms @ 20 kHz Now you can probably find farad-sized electrolytics -advertised- for lower ESR, but they don't tell you the frequency or conditions under which that ESR was measured. There are engineering standards for measuring such things as ESR. Industry has to deal with these standards all the time. But as long as these caps are not marketed for industrial use the manufacturers can declare an ESR that is measured in any way they want, even by measuring the cap in a series resonant circuit with a high impedance source. IOW, it's a lot of hype, just like the ridiculous gain figures that are advertised for some CB antennas. About the lowest -real- ESR you will find among those ultra-high-density caps is about 0.2 ohms, and it will cost you most of a paycheck (two or three paychecks if you have a McJob). The problem here is one that has existed since the first capacitor was invented: There is a tradeoff between charge density (uF per cubic inch) and ESR. Whenever the physical size of a capacitor gets too large, it usually dictates a different type of capacitor. A 1 farad air capacitor would have an extremely low ESR, but it would probably be as big as an aircraft carrier (which would introduce other problems, but those are ignored for the sake of this example). If it was an oil/paper capacitor it might be as big as a house. Even an aluminum electrolytic of 1 farad would still be quite large for a mobile application. So these monster caps are built with a different type of electrolytic process, one that packs more farads into a smaller space, but at the expense of increased dielectric absorption/hysteresis, i.e, a higher ESR. Put more simply, if these big caps were as good as the advertisers claim them to be, they would have replaced aluminum electrolytics a long, long time ago. They haven't. Put even more simply, if it looks too good to be true, it probably is. If you don't believe me, buy one and measure it yourself. You will need a very low impedance source and load, then measure the difference in ripple voltage on a scope. Post the results. And just to make my point about smaller caps in parallel being better than one big cap: 381LX472M016H012 4700 uFd @ 16 VDC 0.113 ohms @ 120 Hz 0.085 ohms @ 20 kHz Put ten of the 4700 uFd caps in parallel and you have 47000 uFd, but with an ESR of 0.0113 ohms @ 120 Hz and 0.0085 @ 20 kHz, which is better than the 47000 uFd capacitor. This value would drop the source impedance (in my example from the previous post) from 0.0163 ohms to 0.0067 ohms, meaning the voltage will only drop 0.53 volts on a peak. So in this example, the caps give back three-quarters of the power that is missing from the peaks when run without the caps. Compare that to any size cap with an ESR of 0.2 ohms. ============= "...but I admitted I was wrong, Like a man! Something you and QRM have a problem with. You guys are wrong and you both know it and are both too small to admit it." ---- Twistedhed ---- ============= -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
In , wrote:
snip A one farad capacitor can only supply one amp for one second at one volt. Hardly worth the expense. It can only prevent a voltage drop on the first few peaks of a SSB modulated signal. It's usefulness would be almost totally drained after speaking just one appropriate word, pointless. Then there is not much point in using them in any kind of DC power supply, is there? Of course there is. Do the math, Tnom: Oranges and apples............... P.S. you are a idiot for even equating the two Then explain the operational difference between a power supply filter cap and a cap placed across the input of a load. Duh....!!! A good car battery has, on the average, an source impedance of around 0.01 ohms (dropping 1 volt per 100 amps, which is a darn good battery). Ten feet of #8 AWG has a DC resistance of 0.0063 ohms, and we'll just assume that the negative lead is grounded at 0 ohms. So the total source impedance at the input of the amp is 0.0163 ohms. Now take an amp that can do 500 watts PEP. Assuming 50% efficiency, that means it can draw a maximum of 79.4 amps @ 12.6 volts. But since the source impedance is 0.0163 ohms, the voltage is going to drop 1.3 volts on the peaks, reducing the peak output by 50 watts or more. This is a type of soft-clipping and can result in some significant AF -and- RF distortion. And that's not considering the temperature coefficient of copper, which shows more resistance as it warms up from carrying lots of current, making the situation worse. Adding caps at the power input leads of the amp can significantly reduce the source impedance of the power supply. It -can't- provide more power than the supply is capable of providing, But for how long........."Do the math" ......? I said it -CAN'T- provide more power than the power supply. Are you deaf? but it -can- smooth the voltage ripple just like in any other type of power supply. And what if the vehicle is running? Do the math: If you have a 100 amp alternator (at 13.8 volts), it has a source impedance of .138 ohms, which is significantly higher than the battery, so it's not going to be much help. In fact, because it's going to be so heavily loaded, it's going to introduce some ripple into the power lines, ripple that can be reduced by using caps at the input of the amp. How much capacitance is needed? There is no easy equation. There are a number of factors, such as the source resistance of the battery and alternator, resistance of the wire, ESR of the capacitors, average modulation percentage, PEP watts, etc, etc. Because of the very low impedance required by the amp, low ESR is paramount. Despite the advertised claims, the 'monster' caps usually have an ESR of several ohms, much higher than is usable. Computer-grade electrolytics have a much lower ESR. Using many smaller caps in parallel is better than one big cap because the ESR is much lower. Those are just a few things to consider. But the general rule is to keep adding caps until they no longer make any improvement. I'm really suprised, Tnom. After all the times you have shot your mouth off and been proven wrong on technical topics, you -still- haven't learned to think before you speak. Maybe next time. One thing I am not surprised at........You will ignore the facts, like you normally do to flame the group or express your pseudo theory. Present some FACTS, Tnom. I dare you! Yeah...Right, A few farads will make a justifiable difference. You're to funny. What's funny is watching you choke on basic DC power supply theory (pun intended). ============= "...but I admitted I was wrong, Like a man! Something you and QRM have a problem with. You guys are wrong and you both know it and are both too small to admit it." ---- Twistedhed ---- ============= -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
Well here is some of the specs supplied for a 1 Farad cap from the
manufacture., # Capacitance 1 farad,+/- 5%, 20-24 Volt Surge, 105'C # Dia. 3.54" x H 9.65" # E.S.R. (0.0016 Ohm) Frequency? I don't care it works for me. Good enough for me to use on a SSB amp with a 8 ' run of cable. Like I found out it just helps in reducing the voltage nulls during the audio peaks, and reduces the sudden voltage drops in the electoral system. For $59 bucks it OK to do. That's what he asked and This was my answer. "Frank Gilliland" wrote in message ... In , wrote: snip A one farad capacitor can only supply one amp for one second at one volt. Hardly worth the expense. It can only prevent a voltage drop on the first few peaks of a SSB modulated signal. It's usefulness would be almost totally drained after speaking just one appropriate word, pointless. Then there is not much point in using them in any kind of DC power supply, is there? Of course there is. Do the math, Tnom: Oranges and apples............... P.S. you are a idiot for even equating the two Then explain the operational difference between a power supply filter cap and a cap placed across the input of a load. Duh....!!! A good car battery has, on the average, an source impedance of around 0.01 ohms (dropping 1 volt per 100 amps, which is a darn good battery). Ten feet of #8 AWG has a DC resistance of 0.0063 ohms, and we'll just assume that the negative lead is grounded at 0 ohms. So the total source impedance at the input of the amp is 0.0163 ohms. Now take an amp that can do 500 watts PEP. Assuming 50% efficiency, that means it can draw a maximum of 79.4 amps @ 12.6 volts. But since the source impedance is 0.0163 ohms, the voltage is going to drop 1.3 volts on the peaks, reducing the peak output by 50 watts or more. This is a type of soft-clipping and can result in some significant AF -and- RF distortion. And that's not considering the temperature coefficient of copper, which shows more resistance as it warms up from carrying lots of current, making the situation worse. Adding caps at the power input leads of the amp can significantly reduce the source impedance of the power supply. It -can't- provide more power than the supply is capable of providing, But for how long........."Do the math" .....? I said it -CAN'T- provide more power than the power supply. Are you deaf? but it -can- smooth the voltage ripple just like in any other type of power supply. And what if the vehicle is running? Do the math: If you have a 100 amp alternator (at 13.8 volts), it has a source impedance of .138 ohms, which is significantly higher than the battery, so it's not going to be much help. In fact, because it's going to be so heavily loaded, it's going to introduce some ripple into the power lines, ripple that can be reduced by using caps at the input of the amp. How much capacitance is needed? There is no easy equation. There are a number of factors, such as the source resistance of the battery and alternator, resistance of the wire, ESR of the capacitors, average modulation percentage, PEP watts, etc, etc. Because of the very low impedance required by the amp, low ESR is paramount. Despite the advertised claims, the 'monster' caps usually have an ESR of several ohms, much higher than is usable. Computer-grade electrolytics have a much lower ESR. Using many smaller caps in parallel is better than one big cap because the ESR is much lower. Those are just a few things to consider. But the general rule is to keep adding caps until they no longer make any improvement. I'm really suprised, Tnom. After all the times you have shot your mouth off and been proven wrong on technical topics, you -still- haven't learned to think before you speak. Maybe next time. One thing I am not surprised at........You will ignore the facts, like you normally do to flame the group or express your pseudo theory. Present some FACTS, Tnom. I dare you! Yeah...Right, A few farads will make a justifiable difference. You're to funny. What's funny is watching you choke on basic DC power supply theory (pun intended). ============= "...but I admitted I was wrong, Like a man! Something you and QRM have a problem with. You guys are wrong and you both know it and are both too small to admit it." ---- Twistedhed ---- ============= -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
Well here is some of the specs supplied for a 1 Farad cap from the
manufacture., # Capacitance 1 farad,+/- 5%, 20-24 Volt Surge, 105'C # Dia. 3.54" x H 9.65" # E.S.R. (0.0016 Ohm) Frequency? I don't care it works for me. Good enough for me to use on a SSB amp with a 8 ' run of cable. Like I found out it just helps in reducing the voltage nulls during the audio peaks, and reduces the sudden voltage drops in the electoral system. For $59 bucks it OK to do. That's what he asked and This was my answer. "Frank Gilliland" wrote in message ... In , wrote: snip A one farad capacitor can only supply one amp for one second at one volt. Hardly worth the expense. It can only prevent a voltage drop on the first few peaks of a SSB modulated signal. It's usefulness would be almost totally drained after speaking just one appropriate word, pointless. Then there is not much point in using them in any kind of DC power supply, is there? Of course there is. Do the math, Tnom: Oranges and apples............... P.S. you are a idiot for even equating the two Then explain the operational difference between a power supply filter cap and a cap placed across the input of a load. Duh....!!! A good car battery has, on the average, an source impedance of around 0.01 ohms (dropping 1 volt per 100 amps, which is a darn good battery). Ten feet of #8 AWG has a DC resistance of 0.0063 ohms, and we'll just assume that the negative lead is grounded at 0 ohms. So the total source impedance at the input of the amp is 0.0163 ohms. Now take an amp that can do 500 watts PEP. Assuming 50% efficiency, that means it can draw a maximum of 79.4 amps @ 12.6 volts. But since the source impedance is 0.0163 ohms, the voltage is going to drop 1.3 volts on the peaks, reducing the peak output by 50 watts or more. This is a type of soft-clipping and can result in some significant AF -and- RF distortion. And that's not considering the temperature coefficient of copper, which shows more resistance as it warms up from carrying lots of current, making the situation worse. Adding caps at the power input leads of the amp can significantly reduce the source impedance of the power supply. It -can't- provide more power than the supply is capable of providing, But for how long........."Do the math" .....? I said it -CAN'T- provide more power than the power supply. Are you deaf? but it -can- smooth the voltage ripple just like in any other type of power supply. And what if the vehicle is running? Do the math: If you have a 100 amp alternator (at 13.8 volts), it has a source impedance of .138 ohms, which is significantly higher than the battery, so it's not going to be much help. In fact, because it's going to be so heavily loaded, it's going to introduce some ripple into the power lines, ripple that can be reduced by using caps at the input of the amp. How much capacitance is needed? There is no easy equation. There are a number of factors, such as the source resistance of the battery and alternator, resistance of the wire, ESR of the capacitors, average modulation percentage, PEP watts, etc, etc. Because of the very low impedance required by the amp, low ESR is paramount. Despite the advertised claims, the 'monster' caps usually have an ESR of several ohms, much higher than is usable. Computer-grade electrolytics have a much lower ESR. Using many smaller caps in parallel is better than one big cap because the ESR is much lower. Those are just a few things to consider. But the general rule is to keep adding caps until they no longer make any improvement. I'm really suprised, Tnom. After all the times you have shot your mouth off and been proven wrong on technical topics, you -still- haven't learned to think before you speak. Maybe next time. One thing I am not surprised at........You will ignore the facts, like you normally do to flame the group or express your pseudo theory. Present some FACTS, Tnom. I dare you! Yeah...Right, A few farads will make a justifiable difference. You're to funny. What's funny is watching you choke on basic DC power supply theory (pun intended). ============= "...but I admitted I was wrong, Like a man! Something you and QRM have a problem with. You guys are wrong and you both know it and are both too small to admit it." ---- Twistedhed ---- ============= -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
Snipped because your response is just to ridiculous to even bother reading. In a nutshell your dribble implies that: A one farad cap used on a large amp (dx1600) used on SSB will make a difference.. It can't make any noticeable difference at all. A one farad cap by definition can only supply one amp for one second at a one volt potential. It can not make any real difference on a setup that requires 150 amps on voice peaks. The current draw on voice peaks last long enough to deplete the benefits a one farad cap instantaneously. If the cap is depleted instantaneously then a standard SSB voice keyup would instantaneously absorb all of the caps ability to hold a voltage and make a noticeable difference in a voice communication. The problem is not in the theory but in the relative usefulness of one farad for a 1500 watt amp. One farad is not big enough. |
The point being, if the power supply is not capable of
supplying the current required on SSB voice peaks, then the power supply is too small to start with. The logical 'cure' for a 'too small' power supply is a larger power supply. Any thing else is a 'kloodge', a crutch to prop up a cripple. A capacitor does supply some additional current to the system if it's large enough, but even with very large capacitors the supplied current is going to be very, very tiny in relation to the total current draw. Something else you should remember is that the power supply is also going to have to charge or re-charge that capacitor when it is drained. That means that there is no increase in total current in the system, in fact, there is a decrease since capacitors are not 100% efficient (they do have loss). This means that the current demand on the power supply has increased and the 'hole' is just getting deeper. Capacitors 'work' in audio systems because they 'rob' current from one part of the audio signal and 'deposit' it in another part of the audio signal. If the purpose is to accentuate the high frequencies, then the 'extra' power is robbed from the lower frequencies (or visa-versa). The total average power of the audio signal is not changed (increased), it's only re- ditributed. Some things with audio system do carry over in to RF power amplification systems, but the use of capacitors in the way you want to use them, isn't one of them... 'Doc |
PS - The "'Doc" is a nick name. It was given to me, I didn't choose it. It does not mean that I am any kind of 'doctor', I'm not and I've never claimed to be. When I needed a 'user' name, 'Doc' was there, it's easy for me to remember, and so I use it. If it has any meaning at all, it's personal and not really very 'meaningful' to anyone else. If you don't want to use "'Doc", then my name is Paul, use that, or, whatever your heart desires. I don't care so long as I know it's me you're refering to. I hope that clears that up... 'Doc |
In , wrote:
Snipped because your response is just to ridiculous to even bother reading. In a nutshell your dribble implies that: A one farad cap used on a large amp (dx1600) used on SSB will make a difference.. It can't make any noticeable difference at all. A one farad cap by definition can only supply one amp for one second at a one volt potential. It can not make any real difference on a setup that requires 150 amps on voice peaks. The current draw on voice peaks last long enough to deplete the benefits a one farad cap instantaneously. If the cap is depleted instantaneously then a standard SSB voice keyup would instantaneously absorb all of the caps ability to hold a voltage and make a noticeable difference in a voice communication. Alright, we'll start with what you -do- understand. 1 farad = a charge equivalent to 1 amp across 1 volt for 1 second. That means it can supply 2 amps across 1 volt for 1/2 second, right? Or 4 amps across 1/4 volt for 1 second. With me so far? Now, is the cap going to be supplying the full 12.6 volts? No. It only has to make up the voltage that was dropped by the inadequate impedance of the power supply, which in this case is 1.3 volts. Does the cap need to supply the full 79.4 amps? No. Again, it only needs to make up the current that the power supply can't provide on a peak. The DC input impedance of the amp is 0.16 ohms, so with a voltage drop of 1.3 volts the current required by the caps is going to be 8.2 amps. Does the cap need to continuously supply 8.2 amps @ 1.3 volts? No. Remember, that is the -peak- draw by the amp, and occurs only for a fraction of the cycle. What happens during the rest of the cycle? The capacitor charges back up! So how long is the cycle? For audio amps the slowest cycle is 20 Hz, or 0.05 seconds. And since we are only working the amp one half-cycle at a time, that reduces it even further to 0.025 seconds. Under half of a 20 Hz audio cycle, the time the amp is under peak load is typically going to be less than 1%. But even if the amp spends an unbelievable 10% of the time under peak load, that's 10% of 0.025 seconds, or 0.0025 seconds. Now we know that our cap needs to supply 1.3 volts @ 8.2 amps for 0.0025 seconds. 1.3 * 8.2 * 0.0025 = 0.0267 farads IOW, not only does the cap make a difference, but a 1 farad cap is roughly 40 times bigger than required! As I stated before, the difference lies in the ESR, only part of which is the actual number of farads. A capacitor's internal resistance and dielectric properties can make even a huge capacitor useless for certain applications. The problem is not in the theory but in the relative usefulness of one farad for a 1500 watt amp. One farad is not big enough. Go back to school, Tnom. ============= "...but I admitted I was wrong, Like a man! Something you and QRM have a problem with. You guys are wrong and you both know it and are both too small to admit it." ---- Twistedhed ---- ============= -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
In , 'Doc wrote:
The point being, if the power supply is not capable of supplying the current required on SSB voice peaks, then the power supply is too small to start with. The logical 'cure' for a 'too small' power supply is a larger power supply. Any thing else is a 'kloodge', a crutch to prop up a cripple. A capacitor does supply some additional current to the system if it's large enough, but even with very large capacitors the supplied current is going to be very, very tiny in relation to the total current draw. Something else you should remember is that the power supply is also going to have to charge or re-charge that capacitor when it is drained. That means that there is no increase in total current in the system, in fact, there is a decrease since capacitors are not 100% efficient (they do have loss). This means that the current demand on the power supply has increased and the 'hole' is just getting deeper. Capacitors 'work' in audio systems because they 'rob' current from one part of the audio signal and 'deposit' it in another part of the audio signal. If the purpose is to accentuate the high frequencies, then the 'extra' power is robbed from the lower frequencies (or visa-versa). The total average power of the audio signal is not changed (increased), it's only re- ditributed. Exactly! Some things with audio system do carry over in to RF power amplification systems, but the use of capacitors in the way you want to use them, isn't one of them... 'Doc The power demands of an SSB amp are roughly equivalent to an audio amp simply because of the way SSB works (low input signal, low output power; high input signal, high output power). The current draw follows the audio almost perfectly. Caps -do- help for SSB. ============= "...but I admitted I was wrong, Like a man! Something you and QRM have a problem with. You guys are wrong and you both know it and are both too small to admit it." ---- Twistedhed ---- ============= -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
On Tue, 09 Dec 2003 16:07:37 -0600, 'Doc wrote:
The point being, if the power supply is not capable of supplying the current required on SSB voice peaks, then the power supply is too small to start with. The logical 'cure' for a 'too small' power supply is a larger power supply. Any thing else is a 'kloodge', a crutch to prop up a cripple. A capacitor does supply some additional current to the system if it's large enough, but even with very large capacitors the supplied current is going to be very, very tiny in relation to the total current draw. Something else you should remember is that the power supply is also going to have to charge or re-charge that capacitor when it is drained. That means that there is no increase in total current in the system, in fact, there is a decrease since capacitors are not 100% efficient (they do have loss). This means that the current demand on the power supply has increased and the 'hole' is just getting deeper. Capacitors 'work' in audio systems because they 'rob' current from one part of the audio signal and 'deposit' it in another part of the audio signal. If the purpose is to accentuate the high frequencies, then the 'extra' power is robbed from the lower frequencies (or visa-versa). The total average power of the audio signal is not changed (increased), it's only re- ditributed. Some things with audio system do carry over in to RF power amplification systems, but the use of capacitors in the way you want to use them, isn't one of them... 'Doc Another point is you can't equate SSB voice to music program audio. There is the difference in compression. A direct ratio of the capacitance needed applies to the peak to average ratio of the power output. If your peak to average ratio in amplifier "A" is one half of amplifier "B" then the capacitance needed for amplifier "A" is twice as much as amplifier"B". Music programming by default is suppose to be a true representation of the audio. It requires a large dynamic range. The way this is done is to not use much compression. Music programming has a very large peak to average power ratio. SSB voice is just the opposite. The preferred way to communicate with SSB is to create a high order of intelligibility. This is done with some sort of compression. Compression is desirable with a SSB voice signal. A minimum of 6db of compression over music programming is used. The compression is normally quite a bit higher than 6db. This all means that a SSB voice signal requires (6db) 4 times the capacitance that a HI-FI audio signal requires. It is common practice with audio amps to suggest a minimum of one farad for ever 1000 watts of HI-FI audio, therefore a SSB voice signal would require four farads for 1000 watts or in our case 6 farads for a 1500 watt dx1600. 1 farad cost $50, so we need $300 worth of capacitors in order to see a difference. $300 dollars can better be spent on another battery or two, or better yet a higher capacity alternator. Bottom line on capacitors for SSB............Not worth the money. |
The power demands of an SSB amp are roughly equivalent to an audio amp simply because of the way SSB works (low input signal, low output power; high input signal, high output power). The current draw follows the audio almost perfectly. Caps -do- help for SSB. Not even close. SSB prefers compression and HI-FI abhors it. The difference between the two is a least 6db, therefore SSB takes 4 times the capacitance to make the same difference that a HI-FI could show by using these caps. The example (dx1600) requires at least 6 farads to make a difference. |
In , wrote:
The power demands of an SSB amp are roughly equivalent to an audio amp simply because of the way SSB works (low input signal, low output power; high input signal, high output power). The current draw follows the audio almost perfectly. Caps -do- help for SSB. Not even close. SSB prefers compression and HI-FI abhors it. The difference between the two is a least 6db, therefore SSB takes 4 times the capacitance to make the same difference that a HI-FI could show by using these caps. The DC input power follows the audio input, compressed or not. Is that concept too difficult for you to comprehend? The example (dx1600) requires at least 6 farads to make a difference. Where's the math, Tnom? ============= "...but I admitted I was wrong, Like a man! Something you and QRM have a problem with. You guys are wrong and you both know it and are both too small to admit it." ---- Twistedhed ---- ============= -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
The problem is not in the theory but in the relative usefulness of one farad for a 1500 watt amp. One farad is not big enough. Go back to school, Tnom. I would tell you to go back to school but I'm afraid that wouldn't help. What you actually need is common sense. You actually believe that a SSB voice amplifier operation can be directly compared to a music audio amplifier operation. |
In , wrote:
The problem is not in the theory but in the relative usefulness of one farad for a 1500 watt amp. One farad is not big enough. Go back to school, Tnom. I would tell you to go back to school but I'm afraid that wouldn't help. What you actually need is common sense. You actually believe that a SSB voice amplifier operation can be directly compared to a music audio amplifier operation. The envelope of an SSB signal is nothing more than pure audio. That's what makes it so much more efficient than AM -- no overhead from a continuous carrier, and no redundancy due to an extra sideband. Got a public library nearby? Need a reference? ============= "...but I admitted I was wrong, Like a man! Something you and QRM have a problem with. You guys are wrong and you both know it and are both too small to admit it." ---- Twistedhed ---- ============= -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
On Tue, 09 Dec 2003 19:12:21 -0800, Frank Gilliland
wrote: In , wrote: The power demands of an SSB amp are roughly equivalent to an audio amp simply because of the way SSB works (low input signal, low output power; high input signal, high output power). The current draw follows the audio almost perfectly. Caps -do- help for SSB. Not even close. SSB prefers compression and HI-FI abhors it. The difference between the two is a least 6db, therefore SSB takes 4 times the capacitance to make the same difference that a HI-FI could show by using these caps. The DC input power follows the audio input, compressed or not. Is that concept too difficult for you to comprehend? Trying to create a divergence away from the truth? The truth is not gained by equating DC input to output. The truth is gained by comparing SSB audio compression levels to that of HI- FI audio compression levels. The example (dx1600) requires at least 6 farads to make a difference. Where's the math, Tnom? m, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
I would tell you to go back to school but I'm afraid that wouldn't help. What you actually need is common sense. You actually believe that a SSB voice amplifier operation can be directly compared to a music audio amplifier operation. The envelope of an SSB signal is nothing more than pure audio. That's what makes it so much more efficient than AM -- no overhead from a continuous carrier, and no redundancy due to an extra sideband. Got a public library nearby? Need a reference? I see you are ignoring compression again. We all no the truth now. Your SSB signal has no compression, therefore you sound like a mouse. No wonder no one pays any attention to what you say. |
In , wrote:
I would tell you to go back to school but I'm afraid that wouldn't help. What you actually need is common sense. You actually believe that a SSB voice amplifier operation can be directly compared to a music audio amplifier operation. The envelope of an SSB signal is nothing more than pure audio. That's what makes it so much more efficient than AM -- no overhead from a continuous carrier, and no redundancy due to an extra sideband. Got a public library nearby? Need a reference? I see you are ignoring compression again. We all no the truth now. Your SSB signal has no compression, therefore you sound like a mouse. No wonder no one pays any attention to what you say. COMPRESSION HAS NOTHING TO DO WITH IT, YOU IMBECILE!!! No audio = no RF = quiescient power drain! Good God, man, don't you have ANY reference handy? An ARRL handbook maybe? If you have an SSB amp that is 50% efficient and you input a single-tone audio sine wave for an output of 100 watts, what's the power input? 200 watts + quiescient power. For an output of 200 watts the input is 400 watts + quiescient power. Are you getting it? Or do I need to draw you a picture for when you aren't stoned? ============= "...but I admitted I was wrong, Like a man! Something you and QRM have a problem with. You guys are wrong and you both know it and are both too small to admit it." ---- Twistedhed ---- ============= -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
In , wrote:
On Tue, 09 Dec 2003 19:12:21 -0800, Frank Gilliland wrote: In , wrote: The power demands of an SSB amp are roughly equivalent to an audio amp simply because of the way SSB works (low input signal, low output power; high input signal, high output power). The current draw follows the audio almost perfectly. Caps -do- help for SSB. Not even close. SSB prefers compression and HI-FI abhors it. The difference between the two is a least 6db, therefore SSB takes 4 times the capacitance to make the same difference that a HI-FI could show by using these caps. The DC input power follows the audio input, compressed or not. Is that concept too difficult for you to comprehend? Trying to create a divergence away from the truth? Hardly. I'm trying to make you understand a fundamental concept of radio communications that has eluded your meager education. The truth is not gained by equating DC input to output. The truth is gained by comparing SSB audio compression levels to that of HI- FI audio compression levels. You are truly lost. ============= "...but I admitted I was wrong, Like a man! Something you and QRM have a problem with. You guys are wrong and you both know it and are both too small to admit it." ---- Twistedhed ---- ============= -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
In , wrote:
snip I haven't given up on you yet, Tnom: You have an audio signal of a given frequency, say 400 Hz. Simple enough? Ok. Now, compress the **** out of it. Is it still 400 Hz? YES! Now if it is -still- 400 Hz then it -still- crosses zero twice per cycle, right? YES! And unless you have compressed it into a perfect square wave, it still spends some time where the signal is less than full power, right? RIGHT! Now pick any point on the audio wave. That point represents an equivalent amount of RF power, right? RIGHT! Now one of the characteristics of SSB is that the RF power fluctuates WITH THE AUDIO WAVE from zero to peak, right? RIGHT! So does that mean if, at that point, the RF power output is xxx watts, for an amp that is 50% efficient, the input power will be 2 * xxx watts? YES! Can you pick any point on the audio curve and the same thing will be true? YES! Therefore, we can conclude that the DC current drain on the power supply is proportional to the audio. And you know what, Tnom? IT IS!!! Does it matter if the audio is compressed? NO!!! Do you get it yet? Or are you going to pout and whine about me trying to distort the truth? ============= "...but I admitted I was wrong, Like a man! Something you and QRM have a problem with. You guys are wrong and you both know it and are both too small to admit it." ---- Twistedhed ---- ============= -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
I do agree with you Frank, that Audio power draw is very close to SSB power
draw from the Power supply, Battery, or alternator in a car system. I do not run RF compression even if it does in the amp, and if it does compress, the cap still help in filling out the audio ripple on the supply line. .. O well enough on this. "Frank Gilliland" wrote in message ... In , wrote: snip I haven't given up on you yet, Tnom: You have an audio signal of a given frequency, say 400 Hz. Simple enough? Ok. Now, compress the **** out of it. Is it still 400 Hz? YES! Now if it is -still- 400 Hz then it -still- crosses zero twice per cycle, right? YES! And unless you have compressed it into a perfect square wave, it still spends some time where the signal is less than full power, right? RIGHT! Now pick any point on the audio wave. That point represents an equivalent amount of RF power, right? RIGHT! Now one of the characteristics of SSB is that the RF power fluctuates WITH THE AUDIO WAVE from zero to peak, right? RIGHT! So does that mean if, at that point, the RF power output is xxx watts, for an amp that is 50% efficient, the input power will be 2 * xxx watts? YES! Can you pick any point on the audio curve and the same thing will be true? YES! Therefore, we can conclude that the DC current drain on the power supply is proportional to the audio. And you know what, Tnom? IT IS!!! Does it matter if the audio is compressed? NO!!! Do you get it yet? Or are you going to pout and whine about me trying to distort the truth? ============= "...but I admitted I was wrong, Like a man! Something you and QRM have a problem with. You guys are wrong and you both know it and are both too small to admit it." ---- Twistedhed ---- ============= -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
On Tue, 09 Dec 2003 19:51:03 -0800, Frank Gilliland
wrote: In , wrote: I would tell you to go back to school but I'm afraid that wouldn't help. What you actually need is common sense. You actually believe that a SSB voice amplifier operation can be directly compared to a music audio amplifier operation. The envelope of an SSB signal is nothing more than pure audio. That's what makes it so much more efficient than AM -- no overhead from a continuous carrier, and no redundancy due to an extra sideband. Got a public library nearby? Need a reference? I see you are ignoring compression again. We all no the truth now. Your SSB signal has no compression, therefore you sound like a mouse. No wonder no one pays any attention to what you say. Sure it does. Just like a power supply. A half wave power supply take more filter caps than a full wave. Just like a power supply the more current you draw the more capacitance needed. Compression has everything to do with audio caps. The caps need time to recover to be useful. If the signal is compressed the recovery time is shortened. "COMPRESSION HAS EVERTHING TO DO WITH IT, YOU IMBECILE!!!" |
| All times are GMT +1. The time now is 09:36 PM. |
Powered by vBulletin® Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
RadioBanter.com