The Green Bank Telescope and the National Radio Quiet Zone

From Tom Scott’s YouTube Channel.

Let Tom Scott introduce you to the US National Radio Quiet Zone!

Tucked away in a valley in the Allegheny Mountains in West Virginia, is this: the Green Bank Radio Telescope, the largest steerable radio telescope in the world.  And there are some rather special rules for the area around it…

For more about the Green Bank Observatory: https://science.nrao.edu/facilities/gbt

Read about the United States National Radio Quiet Zone (NRQZ) here at Wikipedia.

And yes, we have our own Radio Quiet Zone around the WA’s Square Kilometre Array.

How-To: Splice Wire to NASA Standards

Via the Make YouTube Channel.

Developed during the heyday of the telegraph, the Lineman’s splice is designed for connections that will be under tension.  It is commonly claimed that, properly made, a Lineman’s splice is stronger than the wires of which it is composed.  In any case, it is a time-proven method, and, coolest of all, one of NASA’s Required Workmanship Standards.  To wit, in a NASA-approved Lineman’s splice:

  1. The conductors shall be pre-tinned.
  2. There shall be at least 3 turns around each conductor and the wraps shall be tight with no gaps between adjacent turns.
  3. The wraps shall not overlap and the ends of the wrap shall be trimmed flush prior to soldering to prevent protruding ends.
  4. Conductors shall not overlap the insulation of the other wire.

Though the Lineman’s splice was originally used without solder, today soldering is common.  And NASA insists on it:

  1. Solder shall wet all elements of the connection.
  2. The solder shall fillet between connection elements over the complete periphery
    of the connection.

This material comes from page 84 of NASA-STD 8739.4 (PDF), which is a great reference if you’re interested in best practices for interconnecting cables and wires.

Hurricane Matthew update from ARRL

From the ARRL, original post here.  10/05/2016

hurricane-matthew

[UPDATED 2016-10-05 @1832 UTC] Amateur Radio Emergency Service (ARES) groups in counties along Florida’s east coast are now at a Level 2 (local) activation for Hurricane Matthew.  A Level 1 (statewide) declaration is expected by Thursday, October 6, according to Northern Florida Section Manager Steve Szabo WB4OMM.  He said The Statewide Amateur Radio Network (SARnet) will be activated on October 6 as well.  SARnet is a network of linked UHF repeaters serving Florida.  During a significant emergency, SARnet may be called upon for support through an official state emergency request.

Several US Eastern Seaboard states are ramping up plans to deal with the storm’s arrival.  Florida and other coastal states already have issued evacuation orders for some counties, and Florida is bracing for a possible direct hit by Hurricane Matthew.  The storm is reported to have caused at least 10 deaths in the Caribbean.

As of 1800 UTC, the National Hurricane Center (NHC) in Miami reported that Hurricane Matthew was about 70 miles north-northeast of Cabo Lucrecia, Cuba, and about 70 miles south of Long Island in the Bahamas.  The storm is packing maximum sustained winds of 120 MPH and is moving northwest at 12 MPH.  After slamming Haiti, the storm’s intensity diminished to category 3. Hurricane and tropical storm watches and warnings are in effect for parts of Florida.  The storm is expected to strengthen as it approaches the US, and its effects could last through the weekend.

Hurricane warnings are in effect for Broward, Palm Beach, Martin, St Lucie, Indian River, and Okeechobee Counties, along with Lake Okeechobee.  A hurricane watch is in effect for Nassau, Duval, St Johns, Flagler, Clay, Putnam, Volusia, Brevard, Osceola, Orange, and Seminole Counties.  Tropical storm warnings have been posted for Miami-Dade, Monroe, Collier, Hendry, and Glades Counties.  A tropical storm watch remains in effect for Lake, Sumter, Polk, Highlands, Marion, Union, Bradford, Baker, and Alachua Counties.

“Interests elsewhere in the Florida Peninsula and the Florida Keys should monitor the progress of Matthew,” the NHC said.  The storm remains more than 400 miles southeast of Miami Beach. Emergency operations centers in Daytona Beach and in Volusia County are on partial activation.  The Florida State EOC is monitoring. Continue reading →

ORARC Facebook Presence

Facebook

Hi Everyone!

As per the committee’s decision, the club’s Facebook Group has been (nearly) wound-up.  Facebook Groups are designed to allow people with a common interest (that’d be us) to interact and collaborate with one another.  Whilst the idea was sound, the requirement of having to be ON Facebook seemed to keep the majority of members away from the group, leaving only a small contingent of members to do the interacting and collaborating.

Facebook is, however, a fantastic way to promote our cause to new (and probably younger) potentially interested parties, and it would be lax of us to not have a presence on a medium that’s capable of reaching so many people so easily.  As a result, ORARC now has a Facebook Page (as opposed to a group).  The Facebook Page, for all intents and purposes, will essentially mirror the content of the website and provide information on our hobby and our club to people who would otherwise never cross our paths.  No one can post things to our page – we explicitly control the contents.  The page also has a facility for interested parties to contact us should they have any queries, enquiries, etc.

You don’t need to have a Facebook account to view the page either (it’s public) so if you’d like to see what it looks like it’s right here.  It’s obviously a little sparse at the moment but new posts go up automatically in sync with the website, so it won’t take long before there’s a reasonable amount of content.

If you have a Facebook account, it would be appreciated if you could visit the site and give it a like and invite other interested parties (both within and outside of our club) to like it too.  It’s beneficial to our page and it would certainly be a good thing for other Amateurs on Facebook to be exposed to the articles we write and events we host here on the Mid North Coast.

Morse Code on ABC

From SouthgateARC, original post here.

morsecodians-fraternity

ABC in Perth broadcast an interview with Terry Keays, President of the Morsecodians Fraternity of Western Australia.

At the Perth Royal Show some people go looking for the latest gadgets and the newest rides.  The faster, the higher, the more stomach-churning the better!

However some people go to step back in time and one way to do that is by visiting the display for the Morsecodians Fraternity of Western Australia in the heritage area.

Morse code was virtually the text messaging system of its day and a huge number of telegrams were transmitted by Morse before other forms of communication took over.

Terry Keays is President of the Fraternity and is in his mid-80’s.  He trained in Morse code when he worked in the PMG department, starting out in Corrigin.  He has been a familiar face at the Royal Show for many years and chatted to Slim.

Listen to the interview at 
http://blogs.abc.net.au/wa/2016/09/morse-code.html
http://blogs.abc.net.au/files/morse-code—terry-keays-to-air.mp3

Morsecodians Fraternity of Western Australia (Inc.)
http://members.iinet.net.au/~oseagram/mfwahome.html