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

More AO-40 reception



Another successful night, so the equipment apparently works. 

Drake #2:
utc:   az:    el:     MA:  SQ:   IF:         Rng (km): Comment:
0404 159.0 AOS   6.5  31.8                  11,027      No signals
0415  148.1  4.6    8.7  29.8                 13,618      No signals
0416  dropped three trees in the way with the chain saw
0500  131.9 12.1  19.2 43.8  123.299.0  24,498     First signal
0500   135   37.5   real antenna position for best signal???
0502                           44.8  123.298.7  25,971    doppler fast
0508   131.4 12.8  20.9 45.6 123.297.3  26,971     S-7
0508   130   45.0   real antenna position
0524   switched to Drake #1
0524   130.9 14.1  24.5  49.1 435.127.3  28,989     S-9+
0525                             49.8                               signal
fades
0535   131.2 15.2  27.1  51.2 435.129.4 30,979    no lock ao40rcv
0535   120    31     real antenna position

So what happened here?  The keps {01172} had the satellite predicted at low
elevation, but the signal was peaking at elev 45?  Trees were scheduled to
go, but did not block the signal at this high elev {almost looks like AOS
was late}.  

The 123 MHz IF Drake (#2) seemed to perform slightly better than the 435
MHz IF Drake (#1) {though the sat had progressed to higher squint by that
time, so that could be why}.  Drake #1 has a noise floor of S-2.5 (9+) and
Drake #2 noise floor is S-1 (7.0).  (noise floor with preamp on)

Doppler direction seems to have reversed when using the second Drake
{turn-on drift?}.  It appears that there is insufficient signal for me to
copy very well above squint ~49.5, though I did hear the weak signal out to
about squint 53.  

So I have confirmed my limits a bit more.  But what's the deal with the
orbit?  Major arc jet burn, or did I miss an updated keps?  Unfortunately,
I was unable to save the telemetry tonight [recovered 79 blocks last night]. 

Definitions:
Drake #2 123.313 => 2401.318 [completely stock Drake]
Drake #1 435.147 => 2401.318 [xtal change for 435 IF and ext. power]

I won't bore you with this detail from now on, but thought I might get some
observations from the first two nights data...And thanks for those.

Ed



----
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