noise
Usually noise is something to be avoided in communications and electronics. But there are some applications where noise is useful or desirable such as in electronic music or in relaxation devices. In ham radio noise is sometimes used in filter testing and other applications but usually at RF not audio.
I watched a couple of videos on producing audio noise. They both mentioned the MM5837 chip, an 8 pin DIP made by National Semiconductor in the 20th century. It is a pseudorandom Linear Feedback Shift Register of 17 stages that outputs white noise. Interested in repeating the experiments I did some searching on MM5837 and found (of course) that it is long discontinued. I also did a search on ebay and found these:
all in the $10 dollar range. I noticed the Radio Shack carded part and found it in the 1982 catalog:
.
plugging the $2.69 1982 price into the Inflation Calculator (aka the justifier) resulted in:
That's certainly in line with the Ebay prices considering shipping is rolled into the roughly $10 on Ebay. But before buying I put them on watch, sometimes this results in a lower price :)
I also did some more searching and found these offerings from Electric Druid:
https://electricdruid.net/white-noise-source/
https://electricdruid.net/noise2-white-pink-noise-source/
Scanning through the datasheet of the first one revealed that Electric Druid folks don't think too much of the MM5837. Apparently the 17 stages of shifting results in a noise output that repeats every few seconds. The second link provides two audio files to white and pink noise outputs. The white noise is harsher while the pink seems more natural like wind or water. I understand that pink noise is white noise that has a filtered roll-off in response as the frequency is increased. These might be worth trying - Electric Druid does provide the PIC source and data files.
I also found this article:
From the issue here:
https://archive.org/details/silicon-chip/Silicon%20Chip/2005/Silicon%20Chip%202005%2001.pdf
This discrete circuit also looks very promising !
Any tie in to ham radio or kits ? Yes, I was thinking that possibly if any of the above noise sources were keyed that they might make a unique type of noise code practice oscillator that I first saw in QST:
Author Hildreth used an amplified transistor connected as a diode noise source similar to the Silicon Chip noise source.
And down the rabbit hole once again !
Best Regards,
Chuck, WB9KZY
http://wb9kzy.com/ham.htm
I watched a couple of videos on producing audio noise. They both mentioned the MM5837 chip, an 8 pin DIP made by National Semiconductor in the 20th century. It is a pseudorandom Linear Feedback Shift Register of 17 stages that outputs white noise. Interested in repeating the experiments I did some searching on MM5837 and found (of course) that it is long discontinued. I also did a search on ebay and found these:
all in the $10 dollar range. I noticed the Radio Shack carded part and found it in the 1982 catalog:
 |
| so new that the little hole at the top wasn't punched out ! |
plugging the $2.69 1982 price into the Inflation Calculator (aka the justifier) resulted in:
That's certainly in line with the Ebay prices considering shipping is rolled into the roughly $10 on Ebay. But before buying I put them on watch, sometimes this results in a lower price :)
I also did some more searching and found these offerings from Electric Druid:
https://electricdruid.net/white-noise-source/
https://electricdruid.net/noise2-white-pink-noise-source/
Scanning through the datasheet of the first one revealed that Electric Druid folks don't think too much of the MM5837. Apparently the 17 stages of shifting results in a noise output that repeats every few seconds. The second link provides two audio files to white and pink noise outputs. The white noise is harsher while the pink seems more natural like wind or water. I understand that pink noise is white noise that has a filtered roll-off in response as the frequency is increased. These might be worth trying - Electric Druid does provide the PIC source and data files.
I also found this article:
From the issue here:
https://archive.org/details/silicon-chip/Silicon%20Chip/2005/Silicon%20Chip%202005%2001.pdf
This discrete circuit also looks very promising !
Any tie in to ham radio or kits ? Yes, I was thinking that possibly if any of the above noise sources were keyed that they might make a unique type of noise code practice oscillator that I first saw in QST:
Author Hildreth used an amplified transistor connected as a diode noise source similar to the Silicon Chip noise source.
And down the rabbit hole once again !
Best Regards,
Chuck, WB9KZY
http://wb9kzy.com/ham.htm
