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FM without 'pink noise'
Hi group.
I wanna know how can I get the FM signal without that nasty 'pink' noise. I'm not using any kind of external antenna. Greetings!! |
FM without 'pink noise'
Pray tell, in 50+ years of ham radio I have never heard 'pink noise'.
What is it?? Boborato wrote: Hi group. I wanna know how can I get the FM signal without that nasty 'pink' noise. I'm not using any kind of external antenna. Greetings!! |
FM without 'pink noise'
"Dave" wrote in message . .. Pray tell, in 50+ years of ham radio I have never heard 'pink noise'. What is it?? Boborato wrote: Hi group. I wanna know how can I get the FM signal without that nasty 'pink' noise. I'm not using any kind of external antenna. Greetings!! I just used NCH tone generator to make pink noise - sounds like what you hear on a AM when you open the squelch. I can email you a sample if you'd like. :-) Ken |
FM without 'pink noise'
"Boborato"
I wanna know how can I get the FM signal without that nasty 'pink' noise. I'm not using any kind of external antenna. ________________ An FM receiver needs a certain minimum level of r-f voltage at its antenna input terminals to meet its noise performance specification. Stereo mode requires more r-f than monaural, for the same S/N at the receiver output. No doubt if you use an antenna capable of giving your receiver the r-f input signal it needs, your noise level will drop to inaudibility (at least with normal programming). RF |
FM without 'pink noise'
http://en.wikipedia.org/wiki/Pink_noise
Then compare to http://en.wikipedia.org/wiki/White_noise "Dave" wrote in message . .. Pray tell, in 50+ years of ham radio I have never heard 'pink noise'. What is it?? Boborato wrote: Hi group. I wanna know how can I get the FM signal without that nasty 'pink' noise. I'm not using any kind of external antenna. Greetings!! |
FM without 'pink noise'
"Richard Fry" wrote in message
... "Boborato" I wanna know how can I get the FM signal without that nasty 'pink' noise. I'm not using any kind of external antenna. ________________ An FM receiver needs a certain minimum level of r-f voltage at its antenna input terminals to meet its noise performance specification. Stereo mode requires more r-f than monaural, for the same S/N at the receiver output. No doubt if you use an antenna capable of giving your receiver the r-f input signal it needs, your noise level will drop to inaudibility (at least with normal programming). RF In addition to Richard's comments, many higher quality FM receivers employ a "muting" switch on the front panel. The Kenwood KT-8300 has 2 selectable mute settings in addition to off while the NAD 4020B has a single setting with an on/off switch. gb |
FM without 'pink noise'
Ken Bessler wrote:
"Dave" wrote in message . .. Pray tell, in 50+ years of ham radio I have never heard 'pink noise'. What is it?? SNIPPED I just used NCH tone generator to make pink noise - sounds like what you hear on a AM when you open the squelch. I can email you a sample if you'd like. :-) Ken For years we called that 'white' noise or 'background' noise. Now, with a full quieting signal, 20 uv, if it's being heard on FM I'd suspect the discriminator or limiter circuits. I'd start looking at the limiter. |
FM without 'pink noise'
Dave,
If you've never heard of 'pink' noise, then you're probably not a student of noise. In noise parlance, 'white' noise is the term that is usually used for non-bandlimited noise (ie, 'broadband noise'). "Pink' noise, on the other hand, is a term used to refer to bandlimited noise. In practice, anything that comes out of the audio channel of a communications receiver is really 'pink' noise, as the bandwidth is limited to a few KHz. On the other hand, the noise that is incident at the antenna or generated in the front-end is much broader in bandwidth and is more deserving of the term 'white' noise. Joe W3JDR "Dave" wrote in message . .. Pray tell, in 50+ years of ham radio I have never heard 'pink noise'. What is it?? Boborato wrote: Hi group. I wanna know how can I get the FM signal without that nasty 'pink' noise. I'm not using any kind of external antenna. Greetings!! |
FM without 'pink noise'
White noise has a uniformly distributed power spectrum.
Pink noise has a spectrum which smoothly decreases in power with increasing frequency. That is, power is concentrated at the low frequency (or red) end of the spectrum. In a narrow band of audio frequencies they both sound the same. There is no detectable difference between the high and low frequency ends of the narrow band. The two terms are usually applied to very wideband communications systems, ie., from VLF to UHF. Purely randomly generated noise is described as white. Its statistical properties are defined as having a Gaussian amplitude distribution. It is by far the most common natural source of noise. See Google for the Gaussian Distribution or Function. It is simple enough : Exp( - x*x ) ). It occurs throughout Science, Engineering, Medicine, Economics, Statistics and in all facets of human activities, life on this Planet and dead materials. Even politics. It may be said that Blair and Bush lie in the extreme tail of the Gaussian Distribution. Which of the two tails I have been unable to fathom. ---- Reg. |
FM without 'pink noise'
TU
W3JDR wrote: Dave, If you've never heard of 'pink' noise, then you're probably not a student of noise. In noise parlance, 'white' noise is the term that is usually used for non-bandlimited noise (ie, 'broadband noise'). "Pink' noise, on the other hand, is a term used to refer to bandlimited noise. In practice, anything that comes out of the audio channel of a communications receiver is really 'pink' noise, as the bandwidth is limited to a few KHz. On the other hand, the noise that is incident at the antenna or generated in the front-end is much broader in bandwidth and is more deserving of the term 'white' noise. Joe W3JDR "Dave" wrote in message . .. Pray tell, in 50+ years of ham radio I have never heard 'pink noise'. What is it?? Boborato wrote: Hi group. I wanna know how can I get the FM signal without that nasty 'pink' noise. I'm not using any kind of external antenna. Greetings!! |
FM without 'pink noise'
W3JDR wrote:
Dave, If you've never heard of 'pink' noise, then you're probably not a student of noise. In noise parlance, 'white' noise is the term that is usually used for non-bandlimited noise (ie, 'broadband noise'). "Pink' noise, on the other hand, is a term used to refer to bandlimited noise. In practice, anything that comes out of the audio channel of a communications receiver is really 'pink' noise, as the bandwidth is limited to a few KHz. On the other hand, the noise that is incident at the antenna or generated in the front-end is much broader in bandwidth and is more deserving of the term 'white' noise. Joe W3JDR White noise is constant energy/Hz, pink is constant energy/octave. tom K0TAR |
FM without 'pink noise'
See Google for the Gaussian Distribution or Function.
It is simple enough : Exp( - x*x ) ). It occurs throughout Science, Engineering, Medicine, Economics, Statistics and in all facets of human activities, life on this Planet and dead materials. ====================================== Indeed, it is often referred to by statisticians as the "Normal" statistical distribution function. Why such a simple function should be so universal is a matter for conjecture. Unfortunately, elementary statistics and tossing of dice is a much neglected subject in our schools. Japanese, Chinese, Korean, Russian, Indian, Central Asian, even Iraqian, Iranian and Palastinian school children are probably better educated. The whole of human life is just a matter of chance. I consider myself to have been very lucky. Please excuse my computerised wanderings! ---- Reg. |
FM without 'pink noise'
Dave wrote: Ken Bessler wrote: "Dave" wrote in message . .. Pray tell, in 50+ years of ham radio I have never heard 'pink noise'. What is it?? SNIPPED I just used NCH tone generator to make pink noise - sounds like what you hear on a AM when you open the squelch. I can email you a sample if you'd like. :-) Ken For years we called that 'white' noise or 'background' noise. Now, with a full quieting signal, 20 uv, if it's being heard on FM I'd suspect the discriminator or limiter circuits. I'd start looking at the limiter. No No No White noise is used where you want an equal distribution of amplitude across the spectrum you are measuring. Pink noise is used where you need a response that is similar to the graph of human hearing for example. It is nonlinear across the bandwidth. |
FM without 'pink noise'
"Boborato" wrote in message ... Hi group. I wanna know how can I get the FM signal without that nasty 'pink' noise. I'm not using any kind of external antenna. Greetings!! Use an outside antenna |
FM without 'pink noise'
Neat. I especially like the Black Noise...
On Sat, 10 Jun 2006 08:08:24 -0500, "TSnCS" wrote: http://en.wikipedia.org/wiki/Pink_noise Then compare to http://en.wikipedia.org/wiki/White_noise John Ferrell W8CCW |
FM without 'pink noise'
OK here's my take, since all the other answer'ers answered without having
enough info in the first place, in my opinion... Pink niose explanatino #12. What you call the "pink noise" that you see / hear in an FM receiver could be that which is designed into the receiver and therefore not normally removable. You could add preemphasis to "whiten" it up. The reason is that the receiver has "de-emphasis" built in to compensate for the pre-emphasis designed into the transmitters that it will receive, which, in turn, was put there to help enhance the low noise characteristics of the FM mode of transmission. This "de-empnasis" is nothing more than a filter which reduces the high frequency audio copmponents more than the low frewquencies, thus giving it the "pink" or low frequency enhanced characteristic. The term Pink coming from the color red which is the color of lower frequency visible light and we have simply retained that analogy when referring to noise. Narrow band receivers use a simple -6 dB per octave deemphasis across the whole audio band and wide band, broadcast receivers use something similar, but it doesn't extend across the whole audio band. So can you be more speciffic? When do you hear this noise? Why do you want to get rid of it? What are you listening to? 73, Steve, K9DCI "Boborato" wrote in message ... Hi group. I wanna know how can I get the FM signal without that nasty 'pink' noise. I'm not using any kind of external antenna. Greetings!! |
FM without 'pink noise'
"John Ferrell" wrote in message ... Neat. I especially like the Black Noise... Isn't the mute switch nothing more than a black noise generator? 73, Steve, K9DCI |
FM without 'pink noise'
"W3JDR" wrote in message news:YUBig.3630$%m5.685@trnddc04... Dave, If you've never heard of 'pink' noise, then you're probably not a student of noise. In noise parlance, 'white' noise is the term that is usually used for non-bandlimited noise (ie, 'broadband noise'). "Pink' noise, on the other hand, is a term used to refer to bandlimited noise. In practice, anything that comes out of the audio channel of a communications receiver is really 'pink' noise, as the bandwidth is limited to a few KHz. On the other hand, the noise that is incident at the antenna or generated in the front-end is much broader in bandwidth and is more deserving of the term 'white' noise. Joe W3JDR White noise is constant energy/Hz, pink is constant energy/octave. tom K0TAR You're both right. The "classical" definition is Tom's. "White" is a constant energy density. "Pink" is 1/f, which gets to you the octave thing. In looser circles/ discussions, we often call noise which is not infinite in bandwidth or not "flat" in the bandwidth of discussion as "colored" and when the low frequency end has more than the high, "pink" often creeps into the vocabulary. "RED" noise would be what many broadcast FM stations seem to be transmitting now-a-days. 15-20 dB bass boost even on the mics. Really hard to listen to, but liked by the sub woofer crowd we all hear coming blocks away. 73, Steve, K9DCI |
FM without 'pink noise'
"Jimmie D" wrote in message .. . "Boborato" wrote in message ... Hi group. I wanna know how can I get the FM signal without that nasty 'pink' noise. I'm not using any kind of external antenna. Greetings!! Use an outside antenna Ahhhh! Right to the heart of it, Jimmy... 73, Steve, K9DCI |
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