[Date Prev][Date Next][Thread Prev][Thread Next] - [Date Index][Thread Index][Author Index]

Re: Geostationary Satellites?



on 2/20/00 12:19 AM, Frank Grossman at 71042.1303@compuserve.com wrote:

> Somebody in this discussion commented that a network of geosync ham
> transponders would make HF obsolete.  Isn't that the point?  HF is
> obsolete.  

As the person who said that let me tell you something:  HF is NOT obsolete
in any way, shape or form.  IMHO, anyone who thinks that has no clue of what
HF operating is all about.  The remark was made somewhat tounge in cheek.
HF is there because of the challenge.  And your comments about needing large
antennas and lots of power is not accurate either.  Thousands of hams
operate QRP all the time with 5 watts or less and talk all over the world.
When conditions are good, you don't need much power.  And if you call 100
watts that most rigs put out "a lot of power" how many 100 watt light bulbs
do you use in your house?  HF may be obsolete or nearly so for commercial
use.  But take a listen.  The aircraft industry still uses it.  There is
still commercial radio telegraph.  When I was in South America, there were a
TON of commercial outfits using frequencies right around 40 meters for
commercial traffic.  The US is a special case in the world.  Many developing
countries cannot afford the higher cost of satellite networks.

So, HF is NOT obsolete in any way, shape or form.

Secondly, regarding Picosat technology on geosynchronous satellites: Stensat
is operating at an orbit of a couple hundred miles.  A geosynch is about 10
times that (around 23,000 miles I think).  The path loss increases by a
factor of 1/R^2 (or is it 1/R for far field?) where R is the radius out to
the bird.  Stensat has a very low power transmitter.  Something that low
would probably not work well from the distance of 23K miles.  Talk about
needing big antennas.

Sorry if I sound like a smart ass, but it gets my dander up when people call
ANY mode of ham radio obsolete.  We do it for the fun of it.  Just like you
said that people still ride horses for fun even though cars are used for
transportation.  This is a hobby and we do it for the fun of it.

73,

Jon
KE9NA

-------------------------------------
Jon Ogden
KE9NA

Member:  ARRL, AMSAT, DXCC, NRA

http://www.qsl.net/ke9na

"A life lived in fear is a life half lived."

----
Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org



AMSAT Top AMSAT Home