Which gave me a thought (way off topic) perhaps some day the deaf will
hear with glasses that produce colors or a waveform in a small section.
If you where deaf from birth and wore these special glasses your brain
might be able to process that into sound but you would need to wear the
glasses from birth likely to be able to do it.
We process sound from our eardrum I don't see why we could not process
it visually it would just take at least as much time as it does to learn
how to process sound information from your eardrum. You would need to
start from birth while the brain was still developing.
At least you would know what sounds are and when they are happening
might save some lives?
Monroe
-------- Original Message --------
Subject: [AR] Re: SDR Radio's was "infrastructure" (was Re: Amateur
solid rockets for ...)
From: Robert Clark <rgregoryclark@xxxxxxxxx>
Date: Mon, December 18, 2017 10:55 am
To: arocket@xxxxxxxxxxxxx
One more stab at it. Cubesats transmission power is less than 1 watt,
while the NOAA weather satellites transmit at less than 10 watts. So if an
omni can receive a NOAA satellite, can we use 10 of the omnis combined
interferometrically as radio telescope arrays do to get the sensitivity
needed for the cubesats?
Bob Clark
On Sat, Dec 16, 2017 at 2:06 PM, Marcus D. Leech <mleech@xxxxxxxxxx> wrote:
On 12/16/2017 01:36 PM, Robert Clark wrote:
On Mon, Nov 20, 2017 at 7:53 PM, Monroe L. King Jr. <
monroe@xxxxxxxxxxxxxxxxxx> wrote:
Cubesats are typical 1 wattCould a omnidirectional antenna like these work to receive cubesat
Besides that the point is you need a tracker.
My mother has a "general" ham license. lol seriously
No a stationary helical would be no good for a cubesat but almost any
other satellite would be doable.
Monroe
transmissions without tracking, to be able to receive transmissions of any
cubesat overflying the coverage area:
The Lindenblad: The Ultimate Satellite Omni Antenna
by Howard Sodja, W6SHP
w6shp@xxxxxxxxx
based on articles previously published in The AMSAT Journal July 1990 and
November-December 1991 and OSCAR News August 1989 and June 1991.
http://www.amsat.org/articles/w6shp/lindy.html
or:
https://en.wikipedia.org/wiki/Omnidirectional_antenna#/
media/File:Schwarzbeck_RE_1790.jpg
Bob Clark
Omnis have been used for VHF satellites, such as the NOAA POES APT
service. But the transmitters on those sats are fairly loud, compared to
the 1W
cubesat example.
Assuming 5dBi gain antennae on both satellite and ground, then at 150MHz,
the free-space path loss is about 112dB. Our putative cubesat puts out
+30dBm,
so the receiver "sees" -82dBm. Whether that's sufficient to service the
SNR needs of whatever signal you're trying to demodulate is another
question.
Moving up in frequency means the path-loss gets worse, but gain antenna
structures are smaller.
