This week, AMSAT News Service (ANS) cited an August 27 report from AMSAT Vice President-Operations Drew Glasbrenner, KO4MA, saying that a digital mobile radio (DMR) signal has been interfering with the AO-92 (Fox-1D) satellite’s 435.35 MHz uplink frequency. Glasbrenner said hotspots, repeaters, terrestrial simplex, and “anything not satellite” should never transmit in the segments 145.8 – 146.0 MHz or 435 – 438 MHz by international band plan. Well-known satellite enthusiast Patrick Stoddard, WD9EWK/VA7EWK, told ARRL that one DMR hotspot operating on the AO-92 uplink frequency in the St. Louis area has shifted to another frequency. But, he added, “I think there are still issues, since not all hotspots will report their frequencies and positions to websites such as BrandMeister or via APRS, where they appear on other sites such as http://aprs.fi.”
“There are others surely operating near satellite uplinks,” Stoddard added. “For many, the 435 – 438 MHz satellite subband is a big piece of quiet real estate in a busy part of the 70-centimeter band for weak-signal work, repeater links, amateur TV, and other possible uses.”
Stoddard points out that FCC Part 97 addresses Amateur Radio operation in these segments, although regulations in many other countries may not be as detailed. §97.3(a)(7) defines Auxiliary Stations as, “an amateur station, other than in a message forwarding system, that is transmitting communications point-to-point within a system of cooperating amateur stations.”
Stoddard said this would include remote bases, EchoLink and IRLP nodes, and hotspots used for digital voice modes, as well as stations using these hotspots and nodes. Auxiliary stations may not transmit in the 145.8 – 146.0 and 435 – 438 MHz satellite subbands (among others in the 2-meter and 70-centimeter amateur bands), per §97.201(b).
- §97.3(a)(40) defines a repeater as, “an amateur station that simultaneously retransmits the transmission of another amateur station on a different channel or channels.” Stoddard said that because most hotspots operate on a discrete frequency, they would not qualify as repeaters, even if they operate like a repeater, per §97.205(b).
- §97.101(a) stipulates, “In all respects not specifically covered by FCC Rules, each amateur station must be operated in accordance with good engineering and good amateur practice.” Stoddard remarked, “Whether the hotspot is interfering with a satellite downlink in a particular area, or it is interfering with the satellite uplink affecting a much larger area, this would not be good amateur practice.”
- In addition to subbands where hotspots are not permitted, Stoddard said, §97.101(b) is also relevant. It states, “Each station licensee and each control operator must cooperate in selecting transmitting channels and in making the most effective use of the Amateur Service frequencies. No frequency will be assigned for the exclusive use of any station.”
Stoddard noted that frequencies used by satellites are usually incapable of being changed and are coordinated in advance of launch, while hotspots typically are frequency agile, and the frequencies used by those systems can be changed to avoid potential interference to satellites and other stations. — Thanks to AMSAT News Service, Patrick Stoddard, WD9EWK/VA7EWK
Source:ARRL
Antenna
How to Build Cheap Wire Delta Loop Antenna
How to Build Cheap Wire Delta Loop Antenna – Love them or Hate them! Read more
3D Printing – A Ham Radio dipole center with BNC and 1:1 balun
Showing how easy and quick it is to design a custom center insulator for a dipole Here’s the 3D part if you want to print one for yourself.... Read more
Mobile Antenna Model 100A-HP 3.2 to 29 MHz
Mobile Antenna Model 100A-HP When properly installed on your vehicle the Model 100A-HP will provide continuous coverage from 3.2 to 29 MHz with the su... Read more
HF Omniangles HF-28 ( 10 Meters )
HF Omniangles Our HF line of horizontal omnis are a bit different than the VHF and UHF models in that they aren’t as excellent from an omnidirec... Read more
Installation of New 3 El for 80 meters in LZ5R
MILARA CONTEST CLUB LZ1KFM / LZ5R Read more
Review
What”s a Transponder, Anyway?
A question from an Oggie prompted this look at the use of transponders in amateur radio. Read more
POWER POLE DC OUTLET – MFJ 1124 , 1106 , 1126, 1128, 1129, 1104
POWER POLE DC OUTLET – MFJ Read more
My Favorite Mobile Ham Radio Setup VHF/UHF/HF
This rig is a few years in the making. Running a Yaesu FT-891 and FTM-400 lets me cover VHF/UHF and 6 through 40 meters on the go. Read more
MFJ-1835H Cobweb Antenna Review ( High Power version 1.5kW)
For restricted spaces, 5-Bands: 20/17/15/12/10 Meters . . . Restricted space spoiling your operating fun? MFJ Cobweb puts your call back on the map! T... Read more
Review of Chameleon P-Loop Magnetic Antenna
CHA P-LOOP 2.07.0-29.7 MHz The CHA P-LOOP 2.0 was designed with portability, ease of use simplicity, ruggedness and high performance in mind. U... Read more
App - Mobile
Look4Sat: Radio satellite tracker – APP
Ham radio and weather satellite tracker and passes predictor inspired by Gpredict Main features: – Calculating satellite passes for up to one week (16... Read more
DX Alert App ( Mobile )
DX Alert App Instead of being connected to a DX cluster directly you can use DX Alert to monitor the cluster for you and get notifications on your pho... Read more
QTH.app version 0.8.0 released
In amateur radio, the “QTH” Q-code means “What is your position?” when used as a question or “My position is…” when used as a statement. The Automatic... Read more
Koch Morse Trainer Pro – Android App
Take your morse code to the next level with Koch Morse Trainer Pro. The only trainer that supports prosigns (procedural signals) and non-english cha... Read more
Ham Radio License Exam Preparation for Iphone and IPad
Get Your Ham Radio License You are only 35 questions away from getting your Ham radio license. The questions come from a pool of questions publ... Read more