Pulse Devil - The inside scoop

[pml]

Hello JC1,

I probably shouldn't say more about the design until I'm ready to freely give out the entire design, but I've already done the filter part. Words are cheap, right?

I'm wondering how old that terrestrial graph on noise is. Yesterday I saw a similar graph and it was data taken from the 1970's! There's a lot more computers and electronics in the world since the 70's. Do you have any rough figures what the noise spectrum's like now out in the desert? Here's an interesting spectrum chart

http://www.geocities.com/dtmcbride/t...-spectrum.html

ELF 3-30 Hz (Extremely Low Frequency)
Metal Detectors
SLF 30 Hz-300 Hz (Super Low Frequency)
Submarine communications
ULF or VF 300 Hz-3000 Hz (Ultra Low Frequency/Voice Frequency)
Audio - Telephone
VLF 3-30 KHz (Very Low Frequency)
Navigation, Sonar
LF 30-300 KHz (Low Frequency)
9-190 KHz Radionavigation and Maritime
190-405 KHz Aeronautical and Radio Beacons
MF 300 KHz - 3 MHz (Medium Frequency)
AM Radio 535 - 1705 KHz
Police, Fire
2000-2187 Maritime radio, Direction finding
457 KHz Avalanche Beacon
1800-2000 KHz 160 m amateur radio
2300-2500 120 m Shortwave BCB International Radio
HF 3MHz-30MHz (High Frequency) ITU Band 7
3.023 MHz Marine Search and Rescue
4-22 MHz Shortwave Radio
3.2 - 3.4 90 m Shortwave BCB
3.5-4.0 MHz 75/80 m Amateur Radio
4-4.4 MHz Maritime

4.6 Air

4.75-4.95 60 m Shortwave BCB
5.3-5.4 MHz 60 m Amateur Radio USB Max 50 Watts only
5.5 Air
5.9-6.2 49 m Shortwave BCB Band 6
7.0-7.3 MHz 40 m Amateur Radio Shortwave Band 7
9.5-9.9 MHz 31 m Shortwave BCB Band 9
10.1-10.15 MHz 30 m Amateur Radio
11.60-12.10 MHz 25 m Shortwave BCB Band 11
13.57 - 13.87 22 m Shortwave BCB Band 13
14.02-14.3 MHz 20 m Amateur Radio
15.10 - 15.80 19 m Shortwave BCB Band 15
17.48 - 17.90 16 m Shortwave BCB Band 17
18 MHz 17 m Amateur Radio
18.90 - 19.02 15 m Shortwave BCB
21 MHz 15 m Amateur Radio
21.45 - 21.85 13 m Shortwave BCB Band 21
24.9 MHz 12 m Amateur Radio
25.60 - 26.10 11 m Shortwave BCB Band 25
27 Citizens Band (CB) Radio (40 channels)
28-29.7 10 m Amateur Radio

Paul

[Unregistered]

JC1

For everyone interested,

The intent of this article is to provide a basis for amateur research by reviewing some of the work done regarding the ELF/VLF noise floor, and, hopefully, suggest some directions for that research. Knowing what the natural noise level is will allow us to know when our receivers are "hearing" environmental noise and not their own "front-end" noise, and should suggest some areas for individual and networked, or cooperative research.

http://www.vlf.it/naturalnoisefloor/...noisefloor.htm

Important to know when your receiver noise is the problem or the environment is.

JC