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

Welcome newcomers to AO-40



I thought I'd reply to Scott Townley, David Minster, and Magie in one post,
as they are related.

Scott: Frequency of downconverter - This something we all encounter early
on and you want to file this away for use in future tuning as evidenced in
the postings about tuning, ditting, etc.

You began listening at 0400 utc as I did [0420 utc].  The satellite rose
much earlier and I guess most of the activity was over by the time we
arrived.  I had some things to do that slowed me down, it looks like I lost
about 15 dB gain on my Drake {I booted the computer that collects telemetry
after the Drake was connected to the FT-847}.  During booting the computer
keys up the radio via the serial I/F...oops.  It shouldn't have hurt the
Drake since I was in satellite mode...but???  I spent some time checking
things and finally changing out the Drake [got my 15 dB back doing this].
I was disappointed with the lack of activity from 0430-0600 utc.  I noted
that I had to run 50w on uplink tonight due to???  That is about 25w at the
antenna for 1000w ERP.  I mistakingly reported runing 400-600w ERP last
night, should have said 200-300w {forgot to subtract 3 dB coax loss}.  I
heard one guy say he was runing 175w on the uplink! #@*

Scott:  I copied the MB until 0800 fairly strong {getting telemetry OK}, so
you should do better with your 2-foot dish I would think.  Is the DEM one
of the new units built this year {or from a couple years ago?}.  You may
want to get a preamp!  Getting the dish pointed right is your first
challenge {you need to be able to observe the signal strength while doing
this to maximize the narrow beam!}.  I need to get my 432 antenna better
aligned with the dish as my max signal thru the xponder does not exactly
coincide with max beacon heading.

David:  I guess you are new to this list and reading about AO-40.  The
beacon has been the source of telemetry since launch...it is distinctive
sounding so not easy to confuse with any other signal.  The preamp will
open up operation to you that will astound you.  I believe this is the
issue that is being overlooked by many...the preamp in my opinion is not
optional {an exception would be using a down convertor like the UEK with a
NF< 1.0 dB} ...all others need a preamp!

Maggie:  I guess I missed the best operating; by the time I was QRV all you
easterners had gone.  I only worked VE3NPC and W8YIO.  After 0600 it was
just me and the beacon, so I captured some telemetry.  No pacific stations
tonight.  Asia and Australia were active on 7-21-2001.

Well its raining, again, so the roof work will have to wait.  Wx-man/woman
predicts clearing in afternoon so maybe I will get the mode-L stuff
installed.  {some years it rains all thru late July and August and turns to
snow in late Sept...I call this the Alaska monsoon, ugh!}  {my sled dogs
are "soggy doggies" today}

I expect to be on tonight at 0307 AOS.  Higher squint and at apogee {26 and
gets larger as pass continues} so may not be as good for Alaska.  MA=100 at
0414 utc.

Ed
{a side comment to the bb:  I note that my postings usually take >4 hours
to post after I send them???}

----
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