[TowerTalk] Please help me with these questions?

[Daly, Greg TQO]

There are several uses for Cutoff Frequency. In coaxial cables it is the
highest frequency (shortest wavelength) that can be propagated down a
given size coaxial line, at low loss. In waveguide it is the lowest
frequency that a given mode of propagation can exist in a given size
waveguide.

Direct sequence spread spectrum systems are data transmission systems
that purposely add a very fast pseudo random data stream to the traffic.
This spreads the signal over wide bandwidth. If the receiving station
knows the content of the pseudo random data, the signal can be
reconstituted back into it's original low bandwidth stream and the data
can be recovered. This is done to avoid interference. CDMA cell phones
use this method.

Here are some good links to learn about radio... There are a lot more,
Google is very useful for finding them.

http://www.maxim-ic.com/appnotes.cfm/appnote_number/1890

http://www.educatorscorner.com/index.cgi?CONTENT_ID=2601

Go here to learn about ham radio

http://www.arrl.org/hamradio.html

What is CWNA?

Good luck, have fun.

73 DE WB7RSG

Greg.




-----Original Message-----
From: towertalk-bounces at contesting.com
[mailto:towertalk-bounces at contesting.com] On Behalf Of AHMED, Yaseen
Sent: Thursday, March 10, 2005 8:05 AM
To: towertalk at contesting.com
Subject: [TowerTalk] Please help me with these questions?


Hi Folks!
I have some queries on some terms pretty simple for you all:
1.  What is a "Cut off Frequency"?
2. Can anyone explain Direct Sequence Spread Spectrum (DSSS) in detail?
3.  Can any one mail me or show me the link for a ebook on HAM Radio's,
Please...? 4. Any one certified as a CWNA here?

Thanks a Lot,
AHMED