Message boards :
Cafe SETI :
Radio Scanners
Message board moderation
Author | Message |
---|---|
Rev. Tim Olivera Send message Joined: 15 Jan 06 Posts: 20 Credit: 1,717,714 RAC: 0 |
I have a question, I heard that Rockwell built a radio scanner that scanned from 0.0001KHz to 30GHz with no brakes. dose anyone know anything about this scanner?? Dose it actually exist?? If so dose anyone have a model number? Rev. Tim Olivera |
Dr. C.E.T.I. Send message Joined: 29 Feb 00 Posts: 16019 Credit: 794,685 RAC: 0 |
Welcome to the Cafe Rev. Olivera . . . i don't personally know the answer to your question - i am wishing you a Happy Birthday though on February 25th - 57 is a Very Good Number Sir. . . . oh, and btw - luv the 80th anniversary Classic Axe you have - real beauty ;) |
Michael Send message Joined: 21 Aug 99 Posts: 4608 Credit: 7,427,891 RAC: 18 |
I have a question, I heard that Rockwell built a radio scanner that scanned from 0.0001KHz to 30GHz with no brakes. dose anyone know anything about this scanner?? Dose it actually exist?? If so dose anyone have a model number? ELF all the way to SHF ? With a scanner? |
Darth Dogbytes™ Send message Joined: 30 Jul 03 Posts: 7512 Credit: 2,021,148 RAC: 0 |
I have a question, I heard that Rockwell built a radio scanner that scanned from 0.0001KHz to 30GHz with no brakes. dose anyone know anything about this scanner?? Dose it actually exist?? If so dose anyone have a model number? My thoughts exactly...no such animal. The antennas alone, antenna tuning, SWR's are totally incompatiable...sounds like the 200 mile per gallon carborator. Account frozen... |
Michael Send message Joined: 21 Aug 99 Posts: 4608 Credit: 7,427,891 RAC: 18 |
I have a question, I heard that Rockwell built a radio scanner that scanned from 0.0001KHz to 30GHz with no brakes. dose anyone know anything about this scanner?? Dose it actually exist?? If so dose anyone have a model number? Well, I don't think we have to worry about SWR in a receive only antenna. I am more concerned about a receiver capable of signal detection better than a Spectrum Analyzer (Which the best one out there can only do 9Khz - 30Ghz if memory serves me with a narrow bandwidth) Don't matter tho...there is no such beast unless it had multiple receivers, each one being responsible for a certain portion of the radio frequency spectrum....but then we would have gaps :) Plenty of receivers will do it...but what you won't find is a scanner that can sweep that spectrum without *stepping* through the spectrum using multiple receivers = breaks in coverage. |
Darth Dogbytes™ Send message Joined: 30 Jul 03 Posts: 7512 Credit: 2,021,148 RAC: 0 |
You're correct about the SWR, I should have refered to antenna tuning rather than loading (however proper SWR can slightly improve the sensitivity for a specific frequency [critical for transmission], but we're talking about broad spectum here some that doesn't apply as you have already noted). ELF would require too much antenna length to make it practical or have any real sensitivity unless you were right near the source, which is usually quite powerful to get any distance. Correct me if I'm wrong. Account frozen... |
Michael Send message Joined: 21 Aug 99 Posts: 4608 Credit: 7,427,891 RAC: 18 |
You're correct about the SWR, I should have refered to antenna tuning rather than loading. ELF would require too much antenna length to make it practical or have any real sensitivity unless you were right near the source, which is usually quite powerful to get any distance. Correct me if I'm wrong. The lower the frequency, the less attenuation/absorption. Which means a lower freq can travel MUCH farther than a higher frequency at the same power inside our atmosphere. in the case of receiving antennas..they just need to have a LARGE surface area for collection..no need to match wavelength of the frequency you want to listen to...the greater the surface area to collect...the higher in amplitude the signal will be by the time it hits the receiver. Bigger antenna is better. Which is why in my previous post I focused my attention on the receiver. |
Michael Send message Joined: 21 Aug 99 Posts: 4608 Credit: 7,427,891 RAC: 18 |
Something else I want to point out before I turn in for the night. Scanners are coherent receivers..ie; the receiver is built for a specific type of signal(s). In other words, if we already know what the modulated or unmodulated signal will look like to the receiver, we can build it to specifically receive and "do something" with that signal. Such as demodulate a signal and we get the human voice, or television, or data..etc etc. In the case of Seti@Home, we have no idea what the alien signal will look like. So the receiver(s) (I think) are most likely non-coherent (simple) receiver that just sucks up all RF energy. Whew! Thats allot of CRAP to record. We then have to not only analyze the recorded junk, but then we have to find a signal, but not only a signal, one that would appear to be unnatural...and be able to pull it out of all the noise. And lemme tell you our universe is NOISY. If you had an AM radio and could tune into the water hole, you would never know if an "et" signal hit your receiver. Well, you might hear something, but since your AM receiver is built to demodulate signals that are modulated by amplitude, you might hear a loud "something"...we would never know....and in the case of an FM receiver, you would not hear even the tiniest of whispers. More food for thought.... |
John McLeod VII Send message Joined: 15 Jul 99 Posts: 24806 Credit: 790,712 RAC: 0 |
We also have no real idea what the carrier frequency is for an ET signal. BOINC WIKI |
Darth Dogbytes™ Send message Joined: 30 Jul 03 Posts: 7512 Credit: 2,021,148 RAC: 0 |
Maybe they left behind a tin can floating in space with a long string attached to it...? Account frozen... |
BillHyland Send message Joined: 30 Apr 04 Posts: 907 Credit: 5,764,172 RAC: 0 |
Met Mr. Paul once when I lived in Waukesha, WI. Nice guy. |
Fuzzy Hollynoodles Send message Joined: 3 Apr 99 Posts: 9659 Credit: 251,998 RAC: 0 |
Maybe they left behind a tin can floating in space with a long string attached to it...? String theory??? ;-D LOL Good one, Dogbytes! And welcome to the Cafe, Rev. Tim Olivera. :-) "I'm trying to maintain a shred of dignity in this world." - Me |
Dr. C.E.T.I. Send message Joined: 29 Feb 00 Posts: 16019 Credit: 794,685 RAC: 0 |
|
Michael Send message Joined: 21 Aug 99 Posts: 4608 Credit: 7,427,891 RAC: 18 |
|
Misfit Send message Joined: 21 Jun 01 Posts: 21804 Credit: 2,815,091 RAC: 0 |
There are many manufactures of radios in those lower bands. Try browsing the HRO catalog to see if there are any scanners (or transceivers) that match your desired specs. At least you'll be able to identify the various manufacturers and visit their own product websites for more information. Too bad some of the radios with the best coverage are export only. me@rescam.org |
Michael Send message Joined: 21 Aug 99 Posts: 4608 Credit: 7,427,891 RAC: 18 |
There are many manufactures of radios in those lower bands. Try browsing the HRO catalog to see if there are any scanners (or transceivers) that match your desired specs. At least you'll be able to identify the various manufacturers and visit their own product websites for more information. Too bad some of the radios with the best coverage are export only. You won't find one :) |
Misfit Send message Joined: 21 Jun 01 Posts: 21804 Credit: 2,815,091 RAC: 0 |
There are many manufactures of radios in those lower bands. Try browsing the HRO catalog to see if there are any scanners (or transceivers) that match your desired specs. At least you'll be able to identify the various manufacturers and visit their own product websites for more information. Too bad some of the radios with the best coverage are export only. I couldn't afford one :) me@rescam.org |
Michael Send message Joined: 21 Aug 99 Posts: 4608 Credit: 7,427,891 RAC: 18 |
There are many manufactures of radios in those lower bands. Try browsing the HRO catalog to see if there are any scanners (or transceivers) that match your desired specs. At least you'll be able to identify the various manufacturers and visit their own product websites for more information. Too bad some of the radios with the best coverage are export only. And to think I use HRO for all my needs... |
Misfit Send message Joined: 21 Jun 01 Posts: 21804 Credit: 2,815,091 RAC: 0 |
There are many manufactures of radios in those lower bands. Try browsing the HRO catalog to see if there are any scanners (or transceivers) that match your desired specs. At least you'll be able to identify the various manufacturers and visit their own product websites for more information. Too bad some of the radios with the best coverage are export only. They are to hams what Toys R Us is to kids. me@rescam.org |
Michael Send message Joined: 21 Aug 99 Posts: 4608 Credit: 7,427,891 RAC: 18 |
There are many manufactures of radios in those lower bands. Try browsing the HRO catalog to see if there are any scanners (or transceivers) that match your desired specs. At least you'll be able to identify the various manufacturers and visit their own product websites for more information. Too bad some of the radios with the best coverage are export only. Yup :) |
©2024 University of California
SETI@home and Astropulse are funded by grants from the National Science Foundation, NASA, and donations from SETI@home volunteers. AstroPulse is funded in part by the NSF through grant AST-0307956.