Sunday, February 28, 2010

Satellite Activity - VO-52 - 28nd Feb, 10 - evening

VO-52 evening Pass @ 2145 IST was a rather unsuccessful experience as generally it was found that the downlink side was rather noisy today.

In-spite of this, the other stations heard on the VO-52 today were VU2GUR, VU2GZ, VU2ZUB, VU2SWG were heard independent of each station i.e, most stations heard most of the other stations - BUT NO 2-WAY QSO REPORTED. I heard VU2GPS for only one call and then nothing heard.

Surprising phenomenon.  Better luck tomorrow.

Saudi Sat - SO-50


Owned by the "King Abdulaziz University for Science & Technology" , the SaudiSat-1C was launched from the Baikanur Cosmodrome, on 20th Dec, 2002. It is classified as a micro-satellite weighing 10 Kgs. It is placed in an elliptical orbit ranging from 603  (nearest - Perigee)- 713 Kms (farthest - Apogee) from the surface of the earth.  It takes just under 98 mins to complete one orbit around the earth

SO-50 carries several experiments, including a mode J FM amateur repeater experiment operating on 145.850 MHz up link and 436.800 MHz down link. The repeater is available to amateurs worldwide as power permits, using a 67.0 Hertz PL tone on the up link, i.e. your rig must be capable of transmitting with CTCSS, for on-demand activation. SO-50 also has a 10 minute timer that must be armed before use. Transmit a 2 second carrier with a PL tone of 74.4 to arm the timer.

The repeater consists of a miniature VHF receiver with sensitivity of -124dBm, having an IF bandwidth of 15 KHz. The receive antenna is a 1/4 wave vertical mounted in the top corner of the spacecraft. The received Audio is fed to the 250mW UHF transmitter. The downlink antenna is a 1/4 wave mounted in the bottom corner of the spacecraft.

This has been one of the satellites with a consistent signal and  a good footprint.

Capsulated details again
Trigger - 145.850 (74.4Hz CTCSS Tone - activates the satellite for a 10 min slot.)
QSO - 145.850  (67.0 Hz CTCSS Tone)
Listen on 436.795 +/- for doppler shift.

All the best

Satellite Activity - VO-52 - 28nd Feb, 10

The VO-52 Pass at 0930IST at 73Deg elevation wrt to Bangalore once again was a succesful one with lot of activity during almost the entire pass period of about 13 minutes. First signals that I heard was from VU3TYG  -Nitin from Bangalore at around 0931 almost immediately followed by VU2TQC - Jayant from Mumbai and they had a successful 2 way QSO.
Then came in VU2SWG Shankar from Bangalore followed by VU2GUR - Guru also from Bangalore.
I was able to have successful 2 Way QSO with VU2TQC (59/58) and VU2GUR (59/59).  Although I called Nitin and Shankar I was not able to hear any reply.  There was also one other station calling me but did not get the callsign
Another interesting aspect of the activity today, was that Guru was giving a Demo at the SJR Science College, Bangalore for the students from over 100 colleges participating in a Science Exhibition organised there.  Guru was operating from the rooftop of the college and was using a rubberducky initially before switching over to a HB9CV antenna.
Great Show Guru.

Friday, February 26, 2010

Satellite Activity - 26th Feb, 10

There was a favourable HAMSAT (VO-52) pass of 57 deg elevation on the eastern side at 2108 IST today.  Was listening in on 145.900 MHz with the squelch open right from the Access of Satellite (AOS) time of 2108 IST.  I was giving CQ calls on 435.250MHz - the uplink central frequency but was unable to hear my signals on the downlink freq. As the satellite rose to about 13 deg elevation (I was parallely tracking the satellite using Orbitron satellite tracking software), I started hearing VU2GPS and a few seconds later VU2GUR.  I could hear Guru give a report to Partha who did not reply immediately.

As the satellite rose to about 22 Degs, signals from Guru and Partha increased to 59 - receiver quitening and both exchanged 59 reports.  I also was able to contact both of them with similar 59 reports and I was also able to hear myself on the downlink freq. very clearly as the satellite came to the peak elevation of about 57 Deg. 

Later on VU2GZ OM Hari, also put out a call a all three of us heard him and gave him a call.  But unfortunately Hari had not copied us. Probable reason - he was on a rubber ducky antenna from his rooftop !!!! But he made it through the satellite - that is for sure.

Additional information:
Guru was using his horizontal dipole for both VHF and UHF.
I was using a horizontal "Bazooka" for UHF and a Moxon Rectangle antenna for VHF
I am yet to get the Operating setup details of OM Partha VU2GPS

Looking forward to meeting more hams in the near future for two way QSOs.

Monday, February 22, 2010

Satellite Activity - VO-52 - 22nd Feb, 10

Immediately after posting the first writeup, it was time for the VO-52 pass @ 21.30 IST at a good elevation w.r.t. Bangalore @ 61 Deg.

Today we had OM Partha - VU2GPS from Chennai, VU2GZ - Hari, Bangalore, VU2GUR - Guru, Bangalore, and myself who were able to exchange reports.

Later on, as the satellite went northwards, VU2ZUB came in quite clear. OM Daya - VU2DPE was also able to hear the satellite downlink with his handy and rubberducky.

Gud Omen for the New Blog and the first Post.

We have a long way to go. :)

Welcome to the OSCARs - Amateur Satellites

Based on the advice of a few Hams, I decided to start this Blog so that I can share my experiences along with some backgroud of the Amateur Satellites - OSCARs - Orbitting Satellite Carrying Amateur Radio.

For Basic information, I decided to check up on the history of OSCAR. To my surprise, I discovered, that the first OSCAR was launched as early as 1961 - December 21st to be exact. That is just over 48 Years ago. We should be celebrating 50 years of OSCARs next year !!!!!

The first OSCAR was put into an elliptical orbit just about 150Kms going up to about 300 Kms (due to the elliptical Orbit) from the Earth's surface, just above the Earth's atmospheric layer. - This was OSCAR-1. It had a beacon on 144.983 MHz transmitting HI on Morse Code. The Tx power was 140mW from the satellite measuring 9in.x12in.x6in Tall. It lasted for all of 22 days on the air and 50 days in space before it lost altitude and burned up on entry into the atmosphere on Jan 31st 1962.


This was/is just the beginning.

I will also post details on the basic necessitites, equipment requirements, operating procedures, etc. I also welcome questions either as comments on the blog or via direct email to Let us learn more about this interesting operation as we go along.

Information Source: