SSTV From The ISS

From the WIA, original post here.

Date : 09 / 02 / 2017 
Author : Jim Linton – VK3PC

An MAI-75 Experiment SSTV event is planned on February 13 0925-1800 UTC and February 14 1125-1630 UTC.

The downlink frequency is expected to be 145.800 MHz and the transmission mode is expected to be PD180.

This opportunity should cover most of the world during the operational period.

The MAI-75 experiment uses a notebook computer on the ISS Russian Segment, which stores images that are then transmitted to Earth using the ham radio, specifically the onboard Kenwood TM D710E transceiver.

Images received can be posted and viewed here.

Please note that the event, and any ARISS event, is dependent on other activities, schedules and crew responsibilities on the ISS and are subject to change at any time.

While preparations are being finalized please check for new and the most current information on the AMSAT.org and ARISS.org websites, the AMSAT-BB@amsat.org, the ARISS facebook at Amateur Radio On The International Space Station (ARISS) and ARISS twitter @ARISS_status for the latest information on this event. 

Australia’s Oldest Amateur

As spotted by Henry VK2ZHE.

Here’s an article from this month’s (February’s) “The Senior” from Fairfax Regional – the article claims D’Arcy Hancock at 106 as Australia’s oldest active Amateur having been licenced as VK5RJ for 90 years!

From Fairfax Regional’s “The Senior” February 2017 Edition, Page 32.  On the web, click for full size.

Read the paper here – linking direct to the published article is not supported.

Henry VK2ZHE, always the radio spotter, adds:

I like the mid 1970s VK5RJ shack photo accompanying the article.  It shows a Yaesu FT-401 HF transceiver as the centre piece of the VK5RJ operating desk with a Drake SSR-1 Wadley Loop HF receiver on the shelf at the top left.  The black Icom IC-701 all solid state HF transceiver just to the left of the FT-401 is hard to discern.  All state of the art in the 1970s.

Aged Care Online also ran a story on D’Arcy turning 106 in December 2016.  Read it here.

Nick Xenophon to introduce legislation to force ABC to reinstate shortwave radio service

Gary VK2ZKT from RadioSupply spotted the following ABC article explaining that Nick Xenophon may introduce legislation to force the ABC to reinstate their shortwave radio service.  Forwarded by Henry VK2ZHE:

South Australian senator Nick Xenophon says he will introduce legislation to Parliament to force the ABC to reinstate its shortwave radio service, which ended today.

Mr Xenophon said his introduction of legislation next week was not the ideal way to handle the issue, but something had to be done.

“This is a pretty messy way of doing it — putting up a bill — but it will force the ABC management to account,” he said.

“If it means part of the solution is trying to squeeze more money out of the Government, then so be it.”

Mr Xenophon said he believed the ABC had underestimated the impact of its decision.

“The fact is this will affect thousands of Australians who are in remote areas, but it seems it will affect many tens of thousands, perhaps hundreds of thousands of people who are regular Radio Australia listeners throughout the region,” Mr Xenophon told Radio Australia’s Pacific Beat program.

“This is an essential service not just for the bush in Australia but for the region.  I hope I can get bipartisan support to reverse this decision.”

The ABC said shortwave technology was out of date and it would save $1.9 million by cutting the service, which it said would be reinvested in expanding content and services.

The national broadcaster said in a statement there would be a transition program and it “has offered comprehensive advice on how to best access emergency information, ABC News and entertainment”.

“The ABC will assist with the transition to new technologies … as well as the use of modern and reliable devices such as emergency GPS beacons and affordable satellite telephones,” the statement said.

Pastoralists, fishermen among those angered by decision

But the decision has prompted widespread criticism from federal and Northern Territory MPs, pastoralists, fishermen and tour operators, as well as from communities across the Pacific.

“This is shocking news, totally shocking news,” said Francesca Semoso, Deputy Speaker of Bougainville’s Parliament in Papua New Guinea.

“The reason being that wherever you go — if you are up on the rooftop of your house, if you are up in the mountains in Bougainville, if you are down in the valleys, in the Pacific islands in Papua New Guinea, in Bougainville — the only medium that can reach me at that location is shortwave.”

Northern Territory Cattlemen’s Association chief executive Tracey Hayes said the move would have a profound impact on the wellbeing of isolated workers and families.

“There will be just silence in the vehicle and they would have had no contact with the outside world,” she said.

“I can’t imagine what it is going to be like for people who are being put in that position.”

Northern Territory MP Gerry McCarthy said he had invited ABC managing director Michelle Guthrie to his remote electorate to listen to people affected by the decision.

“Come to the Northern Territory for a start, consult with the people that are affected, real Australians out there in remote areas,” he said.

“Also we’ve offered the help and support of the [Northern Territory] Department of Housing and Community Development to go and do some serious analysis about who are the users of shortwave.”

ABC Radio will continue to broadcast across the Northern Territory on FM and AM bands, via the viewer access satellite television (VAST) service, streaming online and via the smartphone app.

See also:

Related Story: ABC’s shortwave radio transition program offers little comfort to Top End fisherman
Related Story: ‘At least 5,000’ people tuning into ABC’s shortwave radio services
Related Story: ABC resists calls to reverse axing of NT shortwave service

WIA Candidates

Following on from the mass resignations at the WIA following their political turmoil, here’s a message from the WIA Returning Officer regarding the Ballot.  This article was originally published here under the title  ‘A message from the 2017 Postal Ballot Returning Officer’.

Date : 03 / 02 / 2017 
Author : John Marshall – WIA 2017 Postal Ballot Returning Officer

The names of candidates seeking election to the Board of Directors of the Wireless Institute of Australia for the 2017 postal ballot is as follows: There are seven positions to be filled. 

  • James Linton – VK3PC 
  • Ewan McLeod – VK4TA
  • Marcus Berglund – VK5WTF
  • David Ford – VK5WP
  • Brian Clarke – VK2GCE
  • John Fisher – VK3DQ
  • Fred Swainston – VK3DAC
  • Garry Page – VK3ZGP
  • Peter Clee – VK8ZZ
  • Justin Giles Clark – VK7TW
  • Philip Wait – VK2ASD
  • Roger Harrison – VK2ZRH
  • Gregory Kelly – VK2GPK

It is a pleasure to see such a large field of candidates.

Your ballot papers will be sent out soon.

It is important that you follow the directions on the ballot paper.  Cross out the names of the candidates you do not vote for, leaving up to seven names not crossed out.  Follow the instructions for placing the ballot paper into its proper envelope, and then the instructions for the outer envelope.

Your postal ballot paper must be returned to the National office (pre addressed on the outer envelope) on or before close of business on 3 April 2017.

John Marshall
2017 Postal Ballot Returning Officer

Passive Intermodulation (PIM) Distortion

Bob VK2ZRE has forwarded the following info regarding a Passive Intermodulation (PIM) distortion – Bob adds:

This article may (should) be of interest to our members.  This is yet another mention and “explanation” of the “rusty bolt” effect.

In short, thanks to Keysight Technologies (emphasis mine) – Passive intermodulation (PIM) is a form of intermodulation distortion that occurs in passive components such as antennas, cables, connectors, or duplexers with two or more high-power input signals.  PIM in the transmission path degrades quality of the wireless communication system.

PIM is becoming a critical parameter recently due to installation of new technologies in wireless communication industries such as higher RF transmission power, multiband operation with a shared common antenna, or wider bandwidth signals with higher probability of PIM in the receiver band.

The article Bob has supplied is from Pasternack Enterprises who provide Low PIM cable assemblies, connectors, adapters, antennas and tappers designed to address applications where PIM can be an issue.  Note that this info is aimed at RF Engineers who work with LTE networks.

Pasternack writes:

What is PIM?

PIM, or Passive Intermodulation, is a type of signal distortion that has become increasingly important to detect and mitigate since LTE networks are particularly sensitive to it.

PIM is created when there are two or more carrier frequencies exposed to non-linear mixing.  The resulting signal will contain additional, unwanted frequencies or intermodulation products.  As the “Passive” portion of the name implies, this non-linear mixing does not involve active devices and is frequently caused by the metallic materials and workmanship of the interconnects and other passive components in the system.  Examples of causes of non-linear mixing:

  • Imperfect electrical connections: surfaces are never perfectly smooth so the areas of contact can have high current densities which can cause heating through a restricted conduction path causing a resistance change.  For this reason connectors should always be tightened to the correct torque.
  • Most metal surfaces have at least a thin layer of oxide which can cause tunnelling, or simply cause a reduced area of conduction. Some believe that this produces the Shottky effect.  This is why a rusty bolt or metal roof near a cell tower can produce a strong PIM distortion signal.
  • Ferromagnetic material: materials such as iron can generate large PIM distortion and should not be used in cellular systems.

As wireless networks become more complex with multiple technologies and system generations in use at a single site, the signals combine to generate this undesired distortion, which interferes with the LTE signals.  Antennas, diplexers, cables, and dirty or loose connectors can be sources of PIM, as well as damaged RF equipment or metal objects near or at a distance from the cell site.

PIM interference can have substantial impacts on the performance of LTE networks, which is why it is so important to wireless operators and their contractors to be able to test for, locate and mitigate PIM.  Acceptable PIM levels vary by system but as an example Test Company Anritsu said that drive tests have found an 18% drop in download speeds when PIM levels were increased from -125 dBm to -105 dBm, even though the latter number can be considered an acceptable PIM level.

Where is PIM tested?

Individual components are often tested for PIM both in the design and production processes in order to ensure that they are not significant PIM sources once they are installed – however, installation is still a critical piece of PIM mitigation because proper connections are critical.  In the case of distributed antenna systems, in some instances the system is tested for PIM as well as individual components.  PIM-certified equipment is becoming more common.  Antennas, for example, may be PIM-certified to a level of -150 dBc and those requirements are increasingly strict.

PIM is also assessed during the siting process for cellular sites, ideally before the cell site and antennas are placed as well as during the installation process.