From the Big Island Amateur Radio Club Newsletter, September 2019. Written by the Club President, NH6ET.
Recently, several amateur radio clubs inHawaii were contacted by individuals from the Hawaii Space Flight Laboratory at the University of Hawaii, Manoa.
These individuals were seeking the amateurradio community’s support of their program’sintended use of the amateur radio bands, fortheir NEUTRON-1 satellite project. The email that the BIARC board received was published in last month’s newsletter.
As I detailed at the July Membership meeting, the BIARC board voted on whether to sign their pre-written letter of support. Several concerns I’ll summarize here, the board did sign that letter.
Several concerns were raised about the request. I communicated these concerns toJoe Speroni (AH0A) ARRL Section Manager forthe Pacific Section. It was Joe who discovered that several other clubs had been sent similar requests to the one we received. Joe escalated our concerns to the ARR Lheadquarters.
The ARRL asked that I engage the HSFL to investigate the matter, in my role of ARRL Assistant Section Manager. Below is a summary of the concerns discussed, how some of those concerns have been addressed, and where we stand in the ongoing process to seek resolution to the remaining concerns.
On interference: The scope detailed in the original request from the HSFL team was not accurate. The inaccuracies contained in their request certainly led to a strong initial reaction from some of us. Namely, the bandwidths theywere seeking to use were exorbitant, to saythe least. The details of their requested use ofthe spectrum were ambiguous at best.
The strictest interpretation of the email toBIARC suggested that the request was to use 10MHz of spectrum in the 2 meter band for an uplink. This is surprising, as the allocation tothe Amateur Radio Service in the 2m bandis only 4MHz wide! If the use of 10MHz ofspectrum was accurate, their use would notonly potentially interfere with the AmateurRadio Service, but other radio services aswell. They also stated intent to use another10MHz of spectrum, but in the 70centimeter band, for the downlink. Their Satellite is to fly alongside the InternationalSpace Station. They will be communicating with it while the ISS is in view of Hawaii.
Essentially, the way their request was written, we were being asked to GIVE UPTHE ENTIRE 2 METER BAND for the duration of every ISS overflight. Similarly, we werebeing asked to GIVE UP THE MAJORITY OFTHE 70 CENTIMETER BAND for the durationof every ISS overflight. Further, WE ARE BEING ASKED TO POTENTIALLY GIVE UP the high speed data portion of the 13centimeter band for the duration of every ISS overflight.
As you can see, I have written two of the three primary interference concerns in the past tense. As I said, their email did not match their actual scope. Through my first few conversations with members of their team, I came to understand their scope to be:
VHF uplink (2 meter amateur band.)
-AFSK modulated signal.
-Channel center of 146.000. Though the yhave signaled willingness to move this to the OSCAR portion of the band.
-10KHz of modulated bandwidth, plus guard bandwidth, so a 12.5KHz channel width.
-Communications intended to be conducted using the AX.25 protocol UHF downlink (70 centimeter band.)
-GFSK modulated signal.
-Channel center of 437.270MHz.o20KHz of modulated bandwidth, plus guard bandwidth, so a 25KHz channel width.oCommunications intended to be conducted using the AX.25 protocol lS-Band up/downlink (13 centimeter amateur band.)
-An OFDM QPSK modulated signal.oChannel center of 2.430GHz.
-20MHz of modulated bandwidth.oCommunications intended to be conducted using a proprietary protocol.
Even after the scope was better understood, one glaring potential for interference exists, and is as of yet unresolved. The potential for interference in the 13cm band remains unchanged. Interference with and from a space station is certainly possible. Amateur Radio operators on Kauai are probably at the greatest risk for interference, as the ground station is located at KauaiCommunity College in Puhi.
You can see the full length article here: September 2019 BIARC Newsletter