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

Why FULLDUPE On is BAD!



Hello fellow packeteers and space junkies....

As I understand this (and my knowledge could be flawed), the radio being 
used for Amateur
communications is running on a single chassis.

IF it is TRANSMITTING, then it can't RECEIVE.  IF the TNC was set up in 
FULLDUPE, then
the TNC would FORCE the radio to STOP listening in order to TRANSMIT by 
virtue of cutting
off the receiver (in spite of its nose?).

How then, can the TNC (via the radio) re-transmit what it cannot 
hear?  Maybe FM in space is
SUPER MAGIC!

FULLDUPE works in two ways....

1.  Separate transmitter and receiver on the same band (with enough 
separation to avoid de-sense).
2.  Separate transmitter and receiver on DIFFERENT band (440 up and 2 down).

With the uplink frequency at 145.990, and the downlink at 145.800, AND with 
a SINGLE (I'm assuming this part) antenna for 2-meters, they would have to 
have the BEST system Chip Angle could design for
separation AND a RADIO capable of FULLDUPE!  We already know the TNC is 
capable of FULLDUPE.

I would suggest (for the future or NOW), that if FULLDUPE be implemented, 
it be done cross-band.

Another thing must also be mentioned.  He who CAPTURES the receiver 
WINS!  With FM, its all about
CAPTURE!  To guaranty your success, a BEAM (M2 is my choice) and BIG POWER 
is needed.  This
is not a good thing...but it does guaranty success.

Here is where I'm at...

I wanted to make a contact via the ISS and see a return with my 
callsign.  I did that (see below)!  Now I shall monitor so as not to cause 
ANY interference to others who are trying.  I was not a happy camper when I 
tried to connect to a STS mission years ago when a certain GLORY HOUND with 
high power and auto tracking beams HAD to make a connect on EVERY pass.  (I 
sent him a message about that).


1st pass attempt:

04/14/01 21:43:17 K6RIX*>NOCALL>CQ: <UI>:{F0}
04/14/01 21:43:18 K6RIX>NOCALL*>CQ: <UI>:{F0}

2nd pass attempt:

04/14/01 23:19:13 K6RIX*>NOCALL>ISS: <UI>:{F0}
Can anyone hear me?
04/14/01 23:19:14 K6RIX>NOCALL*>ISS: <UI>:{F0}
Can anyone hear me?

04/14/01 23:19:46 K6RIX*>NOCALL>ISS: <UI>:{F0}
This is K6RIX in Wheat Ridge (Denver) Colorado.
04/14/01 23:19:47 K6RIX>NOCALL*>ISS: <UI>:{F0}
This is K6RIX in Wheat Ridge (Denver) Colorado.

04/14/01 23:20:21 N5VFF-1>NOCALL*>DM79: <UI>:{F0}
K6RIX - 59 how me

04/14/01 23:21:56 K6RIX*>NOCALL>ISS: <UI>:{F0}
n5vff 59 gd eve!
04/14/01 23:21:56 K6RIX>NOCALL*>ISS: <UI>:{F0}
n5vff 59 gd eve!

Dino...k6rix@arrl.net

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



AMSAT Top AMSAT Home