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

RE: Newbie Questions - Can't find good answers anywhere

1.  Generally I tune MY receive frequency.  The main reason for this is
because your Doppler shift may not be the same as the person to whom you are
talking.  For the LEO sats like the RS series the bird may be moving away
from you and toward the other guy.  If you tune your transmit to make your
receive constant then he will have trouble keeping up.  If you tune only
your receive and keep your transmit constant then he only has to tune his
For the long period sats like AO-10 and Phase III (whenever it goes) then
you will tune your transmit to keep your receive constant because most
likely your received Doppler will be the same as the other guy's.

3.  Many "Amateur birds" are secondary payloads on commercial birds.  For
instance RS-12/13 is a secondary payload aboard a Cosmos 2123 navigation

4. RS 13 is still alive and well (most of the time)

Kevin, WB5RUE

-----Original Message-----
From: owner-AMSAT-BB@AMSAT.Org [mailto:owner-AMSAT-BB@AMSAT.Org]On
Behalf Of Jon Ogden
Sent: Tuesday, December 14, 1999 10:44 AM
To: amsat-bb@AMSAT.Org
Subject: [amsat-bb] Newbie Questions - Can't find good answers anywhere

Hi all,

Being a newbie to the birds, I have a couple of questions that have come up.
I have looked in a lot of the FAQs but haven't been able to find definitive
answers.  So I thought I'd join this list and ask here.

1.) What is the PROPER way to tune for doppler shift?  I have read somewhere
that you should tune the higher of the two frequencies.  I have tried to do
this.  But others don't.  It seems I hear some people tuning their TX
frequency only.  The manual to my FT-847 seems to indicate changing the TX
frequency and that is the way the radio is set up most easily as well.

So which do you tune?  TX?  RX?  or the upper frequency?  or the lower

2.) A question on SO-35:  All the stuff I can see about it says it has a
"mode B" transponder.  To me this means SSB with a 70 cm uplink and a 2m
downlink.  Is it an SSB bird or is it a digital only bird?  Also, it's made
numerous passes over me in the last day and I have heard nothing.  Does it
have a funky schedule or something??

3.) Why are some "amateur" satellites in "non-amateur" modes (PoSAT for
example).  This doesn't sound too amateur to me!  What gives?

4.) Are there any more plans for any more LEO birds that have SSB
transponders like FO-20 and FO-29?  Are there plans for any SSB birds that
have higher orbits like RS-15 or even higher?

OK, that's it for now.

Thanks for letting me ask some possibly obvious questions.



Jon Ogden


"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

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