July 29, 2012

Battery Power

Here are several very useful and interesting links on the topic of battery power:

W1PNS / WAƘITP / AB8XA Battery Life Estimator

Batteries and Charging Systems for QRP

ARRL Lab Notes - Emergency Power

Duracell 9v Battery

July 28, 2012

Its Meteor Time!

The night sky will be lit in a spectacular display of light streaks in late July through mid-August, 2012 as the Delta Aquarid and Perseid meteor showers combine to create one of the very best meteor displays in Northern Hemisphere.

There are few things as wonderful than camping under the open clear sky far from population centers (and light polution) and taking in a blazing meteor shower.  It is one of those activities that kids, teens, partents, and grandparents all equally enjoy and can share and experience together.  The cost is right too - free.  No equipment is needed to view meteor showers.  Location does however make a difference as cloudy skies, haze, and light polution can all interfere.

So get the family together and head outdoors between July 28 and August 13, 2012 to view and enjoy one of the greatest shows on earth.

NASA photo of a meteor falling earthwards

Good viewing, 73

July 27, 2012

New Jersey QSO Party 2012 - July 28/29, 2012

The New Jersey QSO Party will be back on the air July 28 and 29, 2012.  This is great news for New Jersey hams since it a great event.  2011 sadly marked the first time that anyone can remember that there was no New Jersey QSO Party event. 

Thanks to the Burlington County Radio Club for sponsoring the NJ QSO Party and bringing the event back.

The objectives for the New Jersey QSO Party are:
  • Contact as many NJ amateurs in as many NJ counties as possible. 
  • NJ stations contact as many Amateurs in the US, Canada and the world as possible.
For more information be sure to consult with the New Jersey QSO Party Rules.  Please spread the word about this wonderful event.

Add caption

July 20, 2012

US Army Signal Corp SCR-536 / BC-611 Handi-Talkie

The SCR-536/BC-611 was manufactured by Galvin starting in 1942 and was a breakthrough device - the first "handi-talkie".  This single-channel, crystal-controlled, AM transceiver was capable of operation on 3.5 Mhz to 6 Mhz.  Having 5 tubes and 3 batteries, it produced 36 miliwatts of power that was good for communication within a 1 mile radius.  The hand-held self-contained package made this squad radio a pretty impressive piece of gear in 1942.

US Army Signal Corp SCR-536
US Army Signal Corp’s SCR-536

 This is a short (32 seconds) and interesting demonstration of the BC-611 communicating with a TBX-4.

July 15, 2012

Lightning Strikes The Eiffel Tower

This is an amazing shot of a lightning striking the Eiffel Tower.

Photo of the Eiffel Tower being struck multiple times by lightning
Eiffel Tower Lighting

Summer tis the season of the ham's nemesis - lightning.  Is your station grounding and lightning protection up to task?

Good DX and 73, NJ2X

Be sure to check out our other lightning related articles on NJ2X.com.

July 14, 2012

Sussex County Amateur Radio Club (SCARC) Hamfest July 15, 2012

For New Jersey area hams, the Sussex County Amateur Radio Club (SCARC) Hamfest is tomorrow - July 15, 2012.  We make a point of attending this hamfest ever year.  It is a really wonderful event. 

Hope to see you all there.

73, NJ2X

July 13, 2012

What is a ferrite bead?

Ferrite is a ceramic made from various iron and other ferromagnetic oxides.  A ferrite bead is considered an electric component which effectively acts as an inductor.  Ferrite beads are often used to reflect and absorb RF (which is dissipated as heat).  The frequency range that a ferrite bead absorbs depends on the material it is made from.

"Type 31" and "type 43" ferrite material are both very popular in amateur radio applications such as EMI noise supression and common-mode chokes.  Common-mode chokes are very useful devices that can improve the received noise level by blocking EMI travelling along power and telephone cables within the home.  Common-mode chokes can also help reduce the level of transmited RF travelling in common-mode on the shield of transmission cable and keep it out the home.  Additionally, common-mode chokes can reduce the level transmitted RF travelling into sensitive devices via power cables and cable TV lines.

Fair-Rite publishes an excellent technical paper, "How To Choose Ferrite Components for EMI Supressions".

Be sure to also see our related article, What is the schematic symbol for a ferrite bead? on NJ2X.COM.

NJ2X's built this Anderson Powerpole pigtail with a ferrite bead to supress EMI riding on the 12v DC line

July 10, 2012

Nikola Tesla's Birthday July 10, 1856

Today we remember Nikola Tesla on his birthday.  Tesla was born on July 10, 1856 and forever left his mark on the world through his inventions and vision.

Tesla and spiral coil of his high-frequency transformer at East Houston St. 46, New York.

July 9, 2012

ISS Night Flight - Amazing!

This is positively amazing video footage.  Notice the incredible lightning flashes.

July 8, 2012

National Lightning Detection Network (NLDN)

Did you know the US has a national network of lightning detectors?

Lighting Strikes

The US has a network of over 100 sensors combining lightning detection, direction finding, and time of arrival techniques into an integrated system.  This network is called the National Lightning Detection Network (NLDN) and it is capable of detecting cloud-to-ground lightning flashes at distances up to 400 km across the contiguous United States and extending hundreds of miles into both oceans and beyond the borders of Canada and Mexico.

Be sure to check out our other lightning related articles here on NJ2X.com.

July 7, 2012

When thunder roars, go indoors!

When thunder roars, go indoors.

Be safe.  Don't take chances with lightning.

73, NJ2X

July 6, 2012

So what happens to window line in a lightning strike?

So what happens to window line in a lightning strike?

We had the opportunity to inspect sections of window line that had been subjected to the effects a lightning strike.  Interestingly, the copper wire was completely absent from the plastic.  Copper vampires?

There were a few clues.  The first clue was in the form of copper color specs on the insulation - almost as though it had been lightly and randomly sprayed on by a spray can.  An additional clue was the plastic which showed evidence of violent heating and had two burnt tracks running along where the copper had once been.

All the clues pointed to the copper having been completely vaporized in an instant by the lightning.  This must have been an incredibly violent moment and would have been frightful to witness.  Lightning is an extremely powerful force - it can have 100 million to 1 billion volts, and contains billions of watts.  As lightning passes through air, it can heat the air to 50,000 degrees Fahrenheit: about 5 times hotter than the surface of the sun.

We noticed that AE5X had a similar experience which he posted on his blog.

July 5, 2012

So how often does the Empire State Building get stuck by lightning?

Amazingly, the Empire State Building is struck by lightning, on average, over 100 times a year.  So lightning can and does strick the same place more than once.

Empire State Building Lightning Strike 2006

July 4, 2012

Can lightning strike an airplane?

This is a rather amazing video of  lightning striking an airplane mid-flight.  The plane and passengers were unaffected.  Lightning can strike and object in mid-air.  In fact, it is a relatively common occurrence for commercial aircraft to be struck by lightning.  Fortunately, all commercial aircraft are designed and equipped with lightning protection.

July 1, 2012

Lightning Strikes The Eiffel Tower

This is rather amazing picture Lightning striking the Eiffel Tower circa 1902.  Is your station grounding and lightning surpression up to task?

Lightning striking the Eiffel Tower 1902