SB SAT @ AMSAT   $ANS-028.01
DOVE WATCHERS TO BE RECOGNIZED

HR AMSAT NEWS SERVICE BULLETIN 028.01 FROM AMSAT HQ
SILVER SPRING, MD JANUARY 29, 1994
TO ALL RADIO AMATEURS BT
BID: $ANS-028.01

DOVE (DO-17) Telemetry Watchers Will Be Recognized

This weekend the DOVE (DO-17) Command Team will begin using the DOVE text
message frame to transmit the callsigns of everyone who has sent a DOVE
reception report to Dr. Junior Torres De Castro (PY2BJO) of the Brazilian 
AMSAT Group, BRAMSAT, the owner of DOVE.  Because of the limited length of 
that frame, about 15 calls will be sent at a time and the message will be 
changed about every 3 or 4 days.  This is the DOVE Ground Command Team's way 
of thanking everyone who has sent in reports (several hundred at present).  
Special DOVE QSL cards will also be mailed to those who have reported DOVE 
reception to PY2BJO.  We are particularly interested in hearing about the 
equipment used and the quality of the signals.  We would also like to hear 
about the use of DOVE signals or data in education.  Actual telemetry is 
not needed at this time.

Please send reports to:

Dr. Junior Torres De Castro (PY2BJO)
119 Macaubal
Sao Palo
Brazil 01254

[The AMSAT News Service would like to thank Jim White (WD0E) and the DOVE
 Command Team for this bulletin item.]

/EX

SB SAT @ AMSAT   $ANS-028.02
ANTENNA PORLARIZATION REVISITED

HR AMSAT NEWS SERVICE BULLETIN 028.02 FROM AMSAT HQ
SILVER SPRING, MD JANUARY 29, 1994
TO ALL RADIO AMATEURS BT
BID: $ANS-028.02

Antenna Polarization Sense Revisited By WD0E

There have been many discussions occurring on Compuserve's HAMNET forum and
in various corners of the amateur radio community about the need for
antenna polarity switching while using the OSCAR satellites.  DOVE Command
Team member Jim White (WD0E) wants to add some futher comments about this
important issue based on his years of experience working with the MICROSATs.

             Case For Polarization Switching

  "The following is based on design data, direct measurements and
   experimentation, surveys, and anecdotal evidence from discussion
   threads on the digital birds and Compuserve.  I believe the empirical
   data is correct, but an error or two could certainly have crept in.  I
   submit it for discussion and comment.  The sense (right or left) of the
   circular polarization of the four original MICROSATs changes depending
   on the transmitter in use.  There was no attempt to make a particular
   transmitter any sense.  The way they came out was based on how the semi-
   rigid cable and components could be designed into the transmitter
   module.  Here is a list of the sense of each one:
  
            AO-16 RC 437.050 RHCP
            AO-16 PSK 437.025 LHCP
            DO-17 XMTR A 145.825 LHCP
            DO-17 XMTR B 145.825 RHCP
            WO-18 RC 437.100 RHCP
            WO-18 PSK 437.075
            LO-19 RC (&CW) 437.125 RHCP
            LO-19 PSK 437.050 LHCP

   The AO-16 PSK XMTR and the WO-18 PSK XMTR have problems and are not
   presently in use (although the AO-16 PSK transmitter - with LHCP - was
/EX