Undergrad What is the astronomy reason for no UHF channel 37?

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UHF Channel 37, operating between 608 and 614 MHz, is reserved for radio astronomy to prevent interference with sensitive observations. This frequency is crucial as it allows astronomers to detect weak extraterrestrial radio signals without the noise from commercial broadcasts. The allocation of this channel was a compromise, as radio astronomy typically ranks low in priority for spectrum use compared to commercial interests. The choice of Channel 37 was not arbitrary; it was strategically selected to provide a quiet spot amidst other frequency allocations. Overall, the preservation of this channel enhances the ability to observe important astronomical phenomena.
  • #31
swampwiz said:
a more costly antenna in the upper region
I'm not sure that a Band V antenna would necessarily be more costly but UHF was high tech at the time and I'd be surprised if it wasn't desirable to limit high power stations to Band IV, to start with. Early Klystrons may have been only just able to manage Band IV frequencies. And it wouldn't just be receiving antenna that would have bandwidth problems. Combiner networks are probably cheaper if the four channels are all as close together as other considerations will allow.

Taking propagation, topography and populations into account too makes service planning a serious art, on top of what we've already discussed.
 
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  • #32
Aliens! Aliens I tell you. The frequencies used by channel 37 are also used by scientists to send signals into the cosmos to hopefully get a response. Aliens, pure and simple.
 
  • #33
wackedoutscience said:
Aliens! Aliens I tell you. The frequencies used by channel 37 are also used by scientists to send signals into the cosmos to hopefully get a response. Aliens, pure and simple.
I guess the Aliens published their operating channel in the RSGB Bulletin?
 
  • #34
sophiecentaur said:
I guess the Aliens published their operating channel in the RSGB Bulletin?

No, they just read TV Guide.
 
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  • #35
Here's a nice coincidental article about this that just got published. Basically a team of radio astronomers needed to work within the confines of "engineering" in the construction of the radio telescope. I presume that the corresponding size - and thus natural frequency - was the largest that could be done without making the engineering an order of magnitude more expensive.

(Maybe the author is a lurker here. :cool: )

https://www.vice.com/en/article/dy8by7/why-channel-37-doesnt-exist-and-what-it-has-to-do-with-aliens

You see? The target of my dogged inquisitiveness DID have a logical answer underneath the surface. I feel so Einsteinian now!
 
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  • #36
swampwiz said:
I presume that the corresponding size - and thus natural frequency - was the largest that could be done without making the engineering an order of magnitude more expensive.
I should have said natural wavelength instead of natural frequency.
 

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