Anyone know what a "Microwave Receiver" is?

[amnesiac]

Found this while cleaning house.. looks like a relic from at least 20 years back. It's a Microwave Receiver from this company called "Earth Terminals." What's it do?

I'll get a pic up when I find my camera.

 

[dkozloski]

Earth Terminals is big in satellite communications equipment. You must have found part of an old satellite dish setup.

 

[Howard]

They sent signals using microwaves???


I know they did that, but for residential areas?

 

[dkozloski]

RADAR, satellite uplinks and downlinks, communications, ovens, and a multitude of other devices operate at microwave frequencies(above the UHF band). A microwave receiver operates at microwave frequencies but can be a part of many different systems. "Microwave Receiver" is almost a generic term, depending on the design and purpose. As far as residential use, in this area there is a TV distribution system that you can subscribe to that puts a small dish on your house that points at an antenna on the top of a high hill instead of the usual stationary spacecraft.

 

[capybara]

sitting at the center of the microware dish is a downconverter that converts from microwave to
baseband. (TYPICALLY 160 mhz or 47 MHZ).
baseband is sent thru the coax into the receiver. the receiver downconverts a second time, into the CHANNELS. for example channel 2 is
....um i forget but you get the idea. yes?

 

[geekender]

Actually, I know of a few places that still use microwave transmission. It was cheap compared to other forms of transport, but was affected by weather more so than a hard-wired connection.


From Webopaedia.com:

MMDS

Short for Multipoint Microwave Distribution System, also know as Multi-channel Multi-point Distribution System and wireless cable, is another wireless broadband technology for Internet Access.

MMDS channels come in 6 MHz chunks and run on frequencies licensed exclusively by the Federal Communications Commission.


MMDS is a line-of-sight service (see Fresnel Zone definition), so it won't work well around mountains, but it will work in rural areas, where copper lines are not available.

 

[capybara]

dude, microwave is still plenty popular: 802.11 is microwave.
so are 2 gig corless phones, studio to transmitter links (stl) at 18 ghz,
and look at the nearest mountaintop: see all those microwave repeaters up there?
and satellite tv and satellite modems (such as DirecPC)
operate on microwave also

 

[earthman]

Heh if microwave has been displaced by some new bandwidth, I'd like to know what that is.

 

[Smilin]

hehe I thought a microwave reciever was like a hotdog or popcorn or some hot-chocolate or something.

 

[merlocka]

Wow, I get to post in High Tech forum!?!

"Microwaves" are nothing more than a classification for RF signals with a wavelength of 1mm to 1 meter.

Since frequency = c/wavelength (c = speed of light), these frequencies turn out to be between 300MHz to 300GHz.

On the low end, RF geeks usually categorize the signals by their FCC Bands which is something like (from memory, so don't sue me)

AM - .535 - .1605 MHz
FM - 88 - 108 MHz
VHF TV - 54 - 88 MHz
UHF TV - 170 - 8xx MHz (not positive)

There is a break in UHF at like 200 something and it resumes at 400 something MHz. Everything above the second chunk of UHF is microwave, until you get to infrared

So your cell phones (all of em... GSM, AMPS, CDMA, TDMA, iDEN, WCDMA), beepers, wireless mice, 802.11b, 801.11a, Bluetooth, Cordless phones, and a TON of other stuff can all be considered "microwave" devices.

Microwave technology was really introduced as a result of RADAR experiments in the 1930's and 40's when the British figured out that VHF wouldn't work that great.

w00t, I contributed.

 

[Hop]

If I'm not mistaken, my dish (Sprint Broadband Direct, pronounced "Sprint Narrowband Indirect") transmits and receives in the microwave band. Too bad I can't amp up the volume to a couple of megawatts and redirect it towards their network operations center. Wouldn't matter anyway, there isn't a brain one there to fry.

Hop