The RF Crew met at ASA today from about 10 AM until 2 PM for another on-air practice session using the ISS Packet Robot. Executive summary:  things went very well for both passes — still some gremlins, but nothing that wasn’t overcome before either pass.

The computer used for Doppler and Packet was still suffering from being introduced to the Rotor Controller this past Thursday, which necessitated a reinstall of the software to stop the obscure german error messages.  But that gave us a great opportunity to practice manual Doppler correction (preprogrammed channels in the IC-9100) which worked fine for the first pass.  The install was completed between the two passes, and things worked great on the 2nd pass.

The Rotor Control laptop was back and working fine.  It’s always a test of faith to wait for the clicking of relays and changing displays that doesn’t happen until until the ISS is about 5 degrees above the horizon.  I would suggest moving the array by manual control to be pointing in the right general direction.  The TLE file was about 10 days old (pre-boost) and that caused it to start tracking about 5 minute early. We corrected that for the second pass.  Updating TLEs and verifying PC clocks is on the checklist for the event day.

We tried the antenna polarity switch during the second pass — it did not appear to make any difference with either the RX levels or the SWR on transmit.  We will measure current next saturday to be sure that the relay is actually being energized.

The egg beater was installed after drying it out and sealing things up. The SWR was 1:1 at 144 MHz, rising slowly to 1.2:1 at 146 MHz. During the last 3 minutes of the second pass we tried it on air.  The reality is it will not be very effective — we could hear the ISS Packet Robot faintly in the background (not at all without the preamp on).  And it was obvious that the packet robot was not hearing us at all.  Of course the ISS was only about 10 degrees above the eastern horizon and sinking fast.

Some of the packets from ASA that were reported on the global APRS network were:
12:51:48 EDT: N1ASA>CQ,RS0ISS*,FN41IM,ASA,qAR,N0AGI-1:hello wb3fkp
12:53:47 EDT: N1ASA>CQ,RS0ISS*,FN41IM,ASA,qAR,VA3ROM:>fn41IM -/
12:53:57 EDT: N1ASA>CQ,RS0ISS*,FN41IM,ASA,qAR,VA3ROM:Hello N2RRJ
12:54:18 EDT: N1ASA>CQ,RS0ISS*,FN41IM,ASA,qAR,VA3ROM:Hello
from all saints academy in rhode island

Several NCRC members (Mike, K1NPT, Paul, N1PSX, Bob, WB4SON, and member applicant Charles, K1ECU) met at ASA for our second day of on-air RF testing.  We wanted to get the backup antenna working, but found it slightly worse off that this past weekend, with water dripping out of the matching unit.  Repair work will be undertaken ASAP.  (We actually have a backup to the backup and it is working fine.)

Configuring a backup computer and attempting to run everything off that single machine proved to be both time consuming and error prone.  By the time things were mostly working, the first ISS pass was almost over — too late for RF testing.  The second pass 90 minutes later was better, but the Icom IC-9100 was balky due to the USB connection being handled by a hub, rather than directly by the PC.

Another RF Practice Session is planned for 10 AM this coming Saturday, Apr 23, through about 2 PM.  We will be back to a multiple PC setup, so things will work much better.

Invited guests and students will receive a “goodie bag” that will include an informational Trifold Brochure on NCRC, among other things.  You can see the Trifold here.  It will be available at various club activities throughout this year.

While we still don’t know the final contact date, it will likely be between May 3rd to May 6th shortly after noon.

A large number of people, including seven hams from NCRC, were at All Saints Academy from 8:30 AM until 4:30 PM this past Saturday helping to install the RF equipment necessary to provide the communication link between ASA and the International Space Station on the event day (first week of May).

With the assistance of the Middletown Fire Department, and other folks supporting the Audio and Visual equipment, the antenna systems were installed and tested on-air.  We also proved that the interface between the AV and radio gear was functioning.  A digital contact was made between ISS and the school station as well.

A slide show of the activity can be found here.

The NCRC ARISS Team continues to refine their skills. During a fairly low pass this afternoon, they captured a Slow Scan TV (SSTV) image sent from the International Space Station (ISS) to commemorate the first ARISS contact made many years ago (over 1,000 contacts have been made to date).

The pass was a low altitude one, only rising 24 degrees above the horizon. The image began about 3 minutes after ISS rose above the horizon and completed about 3 minutes before the ISS would set. The SSTV images are being sent using the standard VHF FM Voice gear, and signal levels were quite strong, with S-5 or above levels using a Egg-Beater antenna.  The horizontal noise streaks occur during deep fades of the signal.

Image Captured Live April 13, 2016 from 2046 to 2050 UTC

A good discussion of what is required to pickup and decode the SSTV signals can be found here:  https://amsat-uk.org/beginners/iss-sstv/