Illegal downlink in the 70 cm band
A Chinese CZ-4B rocket booster or, more likely, some payload attached to it, appears to have a telemetry downlink on 432.0836 MHz. It is object 43656, 2018-081B.
73, Nico PA0DLO
On 01/20/19 12:07, Nico Janssen wrote:
A Chinese CZ-4B rocket booster or, more likely, some payload attached to it, appears to have a telemetry downlink on 432.0836 MHz. It is object 43656, 2018-081B.
Illegal? Depends on the ITU region it is flying over.
U.S. 47 CFR 97.207(c)(1) defines 435-438 MHz as the allowable transmit frequencies for space stations. However, the ITU just marks 432-438 as AMATEUR (primary region 1) or Amateur (secondary regions 2&3). No distinction is made for amateur-satellite stations.
The ITU does allocate this swath of spectrum to "Earth exploration-satellite (active)". I haven't dug into that.
Unfriendly and uncoordinated? Definitely.
IANAL
--- Zach N0ZGO
Remember to check the RR 5.282.
RR 5.282 In the bands 435-438MHz, 1260-1270MHz, 2400-2450MHz, 3400-3410MHz (in Regions2 and3 only) and 5650-5670MHz, the amateur-satellite service may operate subject to not causing harmful interference to other services operating in accordance with the Table (see No. 5.43). Administrations authorizing such use shall ensure that any harmful interference caused by emissions from a station in the amateur-satellite service is immediately eliminated in accordance with the provisions of No. 25.11. The use of the bands 1 260- 1 270 MHz and 5 650-5 670 MHz by the amateur-satellite service is limited to the Earth-to-space direction.
The amateur-satellite service is available world-wide in the band 435-438 MHzn on a non-interference basis.
73, art….. W4ART Arlington VA
On 20-Jan-2019, at 01:35 PM, Zach Metzinger [email protected] wrote:
On 01/20/19 12:07, Nico Janssen wrote:
A Chinese CZ-4B rocket booster or, more likely, some payload attached to it, appears to have a telemetry downlink on 432.0836 MHz. It is object 43656, 2018-081B.
Illegal? Depends on the ITU region it is flying over.
U.S. 47 CFR 97.207(c)(1) defines 435-438 MHz as the allowable transmit frequencies for space stations. However, the ITU just marks 432-438 as AMATEUR (primary region 1) or Amateur (secondary regions 2&3). No distinction is made for amateur-satellite stations.
The ITU does allocate this swath of spectrum to "Earth exploration-satellite (active)". I haven't dug into that.
Unfriendly and uncoordinated? Definitely.
IANAL
--- Zach N0ZGO _______________________________________________ Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
To thrive in life, you need three bones: a wish bone, a back bone, and a funny bone. - Reba McEntire
On 01/20/19 12:51, Arthur Feller, W4ART wrote:
Remember to check the RR 5.282.
RR 5.282 In the bands *435-438MHz*, 1260-1270MHz, 2400-2450MHz, 3400-3410MHz (in Regions2 and3 only) and 5650-5670MHz, *the amateur-satellite service may operate subject to not causing harmful interference to other services operating in accordance with the Table (see No. **5.43**).
Art-
Good point, but does the telemetry on the CZ-4B use an amateur radio callsign? If not, then perhaps it is part of the China aeronautical radio-navigation service:
5.279A "The use of the frequency band 432-438 MHz by sensors in the Earth exploration-satellite service (active) shall be in accordance with Recommendation ITU-R SA.1260-1. Additionally, the Earth exploration-satellite service (active) in the frequency band 432-438 MHz shall not cause harmful interference to the aeronautical radionavigation service in China."
I'm certainly not defending the use of our spectrum for commercial telemetry, but both China (region 3) and the USA (region 2) are in the Amateur secondary allocation on 70cm. We have to expect some interference on this band.
--- Zach N0ZGO
If the telemetry qualifies in the amateur-satellite service, all’s well. Lots of possibilities exist for making this workable. Need details to know.
73…..
On 20-Jan-2019, at 02:04 PM, Zach Metzinger [email protected] wrote:
On 01/20/19 12:51, Arthur Feller, W4ART wrote:
Remember to check the RR 5.282. RR 5.282 In the bands *435-438MHz*, 1260-1270MHz, 2400-2450MHz, 3400-3410MHz (in Regions2 and3 only) and 5650-5670MHz, *the amateur-satellite service may operate subject to not causing harmful interference to other services operating in accordance with the Table (see No. **5.43**).
Art-
Good point, but does the telemetry on the CZ-4B use an amateur radio callsign? If not, then perhaps it is part of the China aeronautical radio-navigation service:
5.279A "The use of the frequency band 432-438 MHz by sensors in the Earth exploration-satellite service (active) shall be in accordance with Recommendation ITU-R SA.1260-1. Additionally, the Earth exploration-satellite service (active) in the frequency band 432-438 MHz shall not cause harmful interference to the aeronautical radionavigation service in China."
I'm certainly not defending the use of our spectrum for commercial telemetry, but both China (region 3) and the USA (region 2) are in the Amateur secondary allocation on 70cm. We have to expect some interference on this band.
--- Zach N0ZGO _______________________________________________ Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
To thrive in life, you need three bones: a wish bone, a back bone, and a funny bone. - Reba McEntire
This payload may be the 'Candy Tin' mini space station or the 'Tmall International' communications satellite of Alibaba/AliExpress.
http://chinaplus.cri.cn/news/china/9/20181023/199564.html https://www.prnewswire.co.uk/news-releases/aliexpress-to-launch-candy-jar-a-...
73, Nico
On 20-01-19 19:07, Nico Janssen wrote:
A Chinese CZ-4B rocket booster or, more likely, some payload attached to it, appears to have a telemetry downlink on 432.0836 MHz. It is object 43656, 2018-081B.
73, Nico PA0DLO
Yes, received here (western Europe) around 0715/0720 UTC, strong signal, width about 12 kHz, looks like two parallel lines modulated, about 10 kHz from each other.
Thank you Nico for sharing the information, 73,
Jean-Pierre F5YG
On 20/01/19 6:07 PM, Nico Janssen wrote:
A Chinese CZ-4B rocket booster or, more likely, some payload attached to it, appears to have a telemetry downlink on 432.0836 MHz. It is object 43656, 2018-081B.
73, Nico PA0DLO
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
participants (4)
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Arthur Feller, W4ART -
Jean-Pierre Godet -
Nico Janssen -
Zach Metzinger