You used to be able to pick this up downtown before the US Printing Office closed their store. It can be very helpful in understanding the assignments between D.C. and light.

The online version requires zooming and scrolling a lot to read the fine print, but anyway bookmark this link:

http://www.ntia.doc.gov/osmhome/allochrt.pdf

If you want to order it, go to http://www.ntia.doc.gov/osmhome/allochrt.html

I have the 198? version of this chart down in the basement.
It sometimes is the quickest way to find out who/what is operating at a particular place in the spectrum.

Andy

Interesting chart here...what's mind blowing to me is the the higher the frequency the more things turn to pure light? Kind of a spiritual thing?

Kind of a spiritual thing?

No, its a physics thing.

If God has a frequency, it is here: 1420.40575 MHz.

Great...glad you found "him"...don't have a "reciever" to pick up that frequency...someone tune in and give a DX report...actually God invented physics...but back to the chart, it amazes me how small we can get a radio wave this days.

1420.40575 MHz is one of the emission lines of hydrogen. Listeners may find a "hiss" on this frequency that changes in intensity with the time of day.

I hear a constant "hiss" from Broadway's frequency.

As in "What's the Frequency, Kenneth?".
Nut job.

It takes a little effort to hear a signal on 1420.40575:

http://home.comcast.net/~prutchi/index_files/astronomy.htm

A "rubber ducky" on an old Bearcat scanner will not do the job.

>>changes in intensity with the time of day

this is fascinating stuff here...outa my pay grade to again quote a famous one.

The "changes in intensity with the time of day" came out of a Wikipedia article. In the 1930s, this radio noise was first detected, but the engineers and scientists of the day had no clue what was causing it. They suspected that the source was extraterrestrial and that the change in intensity was due to the rotation of the Earth.

The possibility that excited gases could emit spectral lines in the microwave part of the spectrum was not confirmed until 1944. It wasn't until the early 1950s that astronomers were able to determine that the Milky Way galaxy had a spiral structure, by analyzing the microwave radiation received in the vicinity of 1420 MHz. See: http://en.wikipedia.org/wiki/Hydrogen_line

1420 Mhz is among the quietest frequency in regard to background noise in our universe. With hydrogen being the most common element found in the universe, scientists in general and astronomers in particular have deduced that 1420 Mhz would be the most likely "hailing" frequency used by any intelligent life form. Free of most background noise, existing technology permits listening almost as far away as the next galaxy.

I am ET on 1420. Phone home your requests now.

That's quite elaborate setup they have!!

Sitting here at my house with an Anritsu MS2721A Spectrum Analyzer, its real RF quiet at that frequency!

The noise floor is about -144 dB and that's all I see.

What are you using for an antenna? If you have an old 10 foot (or so) sat dish and make a "coffee can" feed for it, you might detect a change in the noise floor a the sun passes in front of the dish.

I'm just using the rubber duckie that came with the unit.

I didn't really expect to see anything!

If it takes a 10' dish to receive the 1420.40575 MHz radiation from the sun, then I assume that a gas discharge tube filled with hydrogen (sometimes called a Geissler tube) would probably emit so little energy at this frequency as to be difficult or impossible to detect. Dr Hendrik van de Hulst, the scientist who, in 1944, gave an explanation of how excited hydrogen atoms might radiate at 1420.40575 was working purely on a theoretical level; he didn't actually detect the microwave emissions with a laboratory setup.

I don't *know* if a 10 foot dish will do the job without a good LNA as used in the article that I linked above. I played a bit several years ago using a coffee can feedhorn mounted (duct tape) on an old 10 foot dish, feeding directly into an ICOM8500, and could not convince myself that that I could see a signal change. I suspect that Bills' Anritsu MS2721A Spectrum Analyzer might be a better receiver than the ICOM.
Got some nice weather sat pictures from GOES birds on 1691 Mhz using that set-up!

That chart has come in handy more than a dozen times for me!

Maybe it's time to go pull out the old Bearcat300 scanner and see what I can hear.I think it only goes up to ~512Mhz though,It's an old beastie.