When to have only voltage gain in an oscillator

In summary, oscillators require gain, in whatever form it may be, to overcome losses and maintain oscillation. While power gain is generally preferred, voltage gain can also be used in certain circuit layouts, such as those utilizing a conventional voltage in, voltage out op-amp. Ultimately, the type of gain chosen for analysis may depend on personal preference or the specific needs of the circuit. However, at a fundamental level, voltage, current, and impedance are all related and can be used to derive one another, making the distinction between voltage and power gain somewhat insignificant.
  • #36
DaveE said:
the representation that is most clear, most standard in industry, or easiest to manipulate is the best option.
dBs are the way to go, of course. Couldn't do without them
DaveE said:
In that case it clearly doesn't have to be power.
But it is Power - by definition. It's taken for granted that a system is using a common impedance throughout so that the Voltages are all proportional to the root of the Power. You know that. I know that.
DaveE said:
people that don't know enough about dB's to be using them at all.
But those people represent all the beginners who can so easily get the wrong message through sloppy use by people who should know better. The existing club rules (notation) are probably too well established to change but, if they had been drawn up correctly in the first place, those beginners would not be suffering. (and passing it on to fellow students). No one who reads this can argue that it's not a problem for students and non-academic technical staff of all vintages. (Double negative but resolvable)

Too lumpy for general use but dBmV600 or dBmV50 would take away any inconsistency.
 
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  • #37
I can understand the need for defined impedances in amplifiers when dealing with dB. Amplifiers have input and output impedances. Not necessarily the same. However, there are some cases it is simply NOT necessary to know. If I monitor a signal that for whatever reason occasionally varies from the source I certainly won't go to the trouble to do the math and compute power each time it changes. I do the math with '20' and accept it. I've actually been in that situation.
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The way I see it is this: Sorry if someone somewhere doesn't understand everything behind decibels. I don't plan on taking personal responsibility for them. The same way if I asked a power line tech working on a line at the end of my driveway what voltage the line is and the reply is 13.5, I don't hold the tech responsible for me misunderstanding and thinking it's no higher than a car battery when in reality it's 13.5 KV. The tech assumed I was smart enough to be speaking his language.
 
  • #38
Averagesupernova said:
compute power each time it changes.
"Compute"? Any change in level on the same line is just a ratio.
Averagesupernova said:
I don't plan on taking personal responsibility for them.
and I wouldn't hold you responsible either. But it does bother me that people get let loose without the right knowledge and expensive mistakes have been made because the dB is not taught properly. If you have 'had conversations' about levels in dB, you must have been aware of the uncertainty in many minds about what should be doing with any readings they've made.

Just browse through some of the stuff that's written on the Web. You'll see it all over the place and it self propagates.
 
  • #39
sophiecentaur said:
Any change in level on the same line is just a ratio
My point exactly.
 
  • #40
But it does bother me that people get let loose without the right knowledge

Just browse through some of the stuff that's written on the Web.
Lol. You better stay away from the internet or it will drive you crazy.
 
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  • #41
Averagesupernova said:
My point exactly.
It was mine too, too, too. We seems to have started to oscillate.
 
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