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…
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:
The conductors shall be pre-tinned.
There shall be at least 3 turns around each conductor and the wraps shall be tight with no gaps between adjacent turns.
The wraps shall not overlap and the ends of the wrap shall be trimmed flush prior to soldering to prevent protruding ends.
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:
Solder shall wet all elements of the connection.
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.
Stuart VK2FSTU is participating in the Great Cycle Challenge! Stuart writes:
Hi fellow amateurs
In Australia, 3 children die of cancer every week.
Right now, cancer is the largest killer of children from disease in Australia. Over 600 Australian children are diagnosed with cancer every year and sadly, 3 die every week.
Great Cycle Challenge has one goal…to fight kids’ cancer!
All funds raised go to support the work of Children’s Medical Research Institute to develop treatments and find a cure for childhood cancer(s).
Your support through Great Cycle Challenge will allow us to continue our work to fight kids’ cancer and give these kids the brighter futures that they deserve.
You can help me help these Kids by making a donation on the following link:
Have you ever hit a repeater 100 miles away with 30 watts at only 40 foot with clear signal reports? Can you even hear a repeater 100 miles away? This antenna can do it and even more. Gains have been signal measured against a dipole up to14.5 dbd* on seven element versions with excellent rear rejection. Five element versions have shown about 12.5 dbd*. Nothing seems as rewarding as building your own antenna and getting great reports.
The EXTREME DREAM BEAM is one of the most fun antenna builds around. Our free plans and video make it easy and fast, perfect for ham radio clubs or the antenna builder enthusiast. The best part of building your own EXTREME DREAM BEAM is the performance when you are done. Not only do you have great fun making it, but it really out performs very costly store bought designs. 5 and 7 element plans are shown in the videos and in the free plans section.
The site also features additional projects and videos, check it out.
The Tokyo Ham Fair was held on the weekend of the 20th and 21st of August 2016. Here’s some neat videos of the manufacturer’s booths courtesy of YouTube user JI1ETUjr. This is the biggest ham fair in the world with around 35,000 visitors (Dayton has around 25,000) – so it should definitely be on your bucket list!
