The Consortium – May 7th – Amateur Satellites for Beginners

Jim K1GND and Bob W1YRC host a monthly ham radio tutorial event that they call
The Consortium“. They meet at the Asia Grille at Lincoln Mall on Rte. 116 in
Lincoln, usually on the first Monday of the month.  Meetings start at 6:30 PM, however, people start arriving after 5:00 PM for dinner before the meeting.

The May 7th Consortium presentation will cover using our repeaters in the sky — Amateur Radio Satellites.  The FM satellites, so called “easy-sats”, are especially simple to use.  All that is required is a dual band HT and simple antennas to have successful contacts.  Online tools or phone applications are then used to track the satellites, letting us know when the satellite will be overhead and where to point the antennas.  The talk will be given by Bob Beatty, WB4SON, who has been using satellites for more than four decades, and who is currently an ARISS Technical Mentor (Amateur Radio aboard the International Space Station).

AO-91 Open for Amateur Use

AMSAT announced early Thanksgiving morning that AO-91 (RadFxSat/Fox-1B), a 1-unit CubeSat has been officially commissioned and turned over for amateur use.

The first QSOs have already happened, and this is proving to be an amazing bird, much better than Fox-1/AO-85).  Folks have already made QSOs with a HT & 1/4 wave whip.

To receive AO-91, simply tune your HT to 145.960 MHz.  When you are ready to step up to transmitting you will need to set up several memory channels to adjust your 70 cm transmit signal to compensate for Doppler.   The transmitter must also be configured with a 67.0 Hz subaudible tone.

AO-91 Doppler Shift Correction
Memory Your Transmit Frequency(With 67 Hz Tone) Your Receive Frequency
Acquisition of Signal (AOS) 435.240 MHz 145.960 MHz
Approaching 435.245 MHz 145.960 MHz
Time of Closest Approach (TCA) 435.250 MHz 145.960 MHz
Departing 435.255 MHz 145.960 MHz
Loss of Signal (LOS) 435.260 MHz 145.960 MHz

Since AO-91 will take about 12 minutes to pass overhead, you will switch to a new TX frequency every 3 minutes or so.

Of course you will need to locate the satellite based on your position. You can use the AMSAT tool (Select AO-91 from the drop down list of satellites, enter your grid square, FN41 for RI, and press “Calculate Position”, then press “Predict” — Note ttimes are in UTC, so subtract 5 hours since we are not currently in DST). N2YO’s Graphical tool is great too, just don’t forget to set your location in the bottom right of the screen.

Tracking subgroup holds second meeting on March 18

A group of NCRC members interested in solving various antenna tracking issues met with Paul K1YBE for four hours this past Saturday.  The objective was to hack into a surplus SeaTrac TVRO dish system usually used to track geostationary satellites on moving vehicles (ships, cars, etc.).

The gang was successful in getting the dish into the “search” mode where it started searching the sky for one of the DBS Satellites.  At this point the communication between the dish platform and controller was captured so that the messages could be analyzed.

It was fascinating to move the dish platform around and see the Inertial Measuring Unit automatically adjust for that motion, keeping the dish pointed to the same part of the sky.

Tracking crew observe controller signals

The Dish Platform includes a full Inertial Measuring Unit

New FM Satellite, BY70-1 is Operational

A new FM Transponder Satellite, BY70-1, is now operational.  This is MUCH easier to work than AO-85, and a bit stronger than SO-50.

Details are:

Uplink: 145.920 MHz  With 67.0 Hz Tone

Downlink: 436.200 MHz

Better work this one quick — its orbit will decay in just a couple of months!

 

Antenna Take-down Day at All Saints

Paul, N1PSX, Jim, KA1ZOU, Jeff, KA1NGP, Bob, WB4SON, and Mike, K1NPT went to All Saints Academy Saturday to remove the antenna array used for the May 6 ARISS event.  Arriving at 9 AM, it took less than an hour to disassemble the antenna on the roof. The Middletown Fire Department arrived at 10 AM and used their Tower Ladder to lift the antenna parts down to the ground.  By 10:25 AM, the job was done, and the ARISS event is just a fond memory!

FD Tower Ladder 2