Tag Archives: K9ZW Just Ram

Sudden Radio Silence in High Risk Scenarios

At Boston we’ve ben attacked as a nation by a bomber.

Our prayers and thoughts are with those killed and injured, and their families.

Our heartfelt thank you and admiration goes out to those who responded, especially as they really didn’t know if they themselves were safe from an additional bombing.

From the news one item dealing with RF jumped out – the Cell Phone Network was instantly taken down by authorities to prevent its use as a trigger for any additional bombs.

Bombs, or IEDs (Improvised Explosive Devices) if you prefer, are typically controlled in two ways:

  • Time
  • Trigger

For Time you can imagine the electronic, mechanical, or chemical functional equivalent of a “fuse.”  Once the fuse is lit, the bomb will be set off at a set period of time afterwards.  The timer can be internal or external, but the functional distinction of a Time Bomb is the device is exploded based on Time as the primary criteria.

For Trigger devices there may be manual control (pull a string, a trip-wire, or hit the detonator with an impact), electronic control (wires back to detonator control box),  a conditional control (goes off when stepped on, moved, opened, when wet, or any other a number of sensor based criteria), radio control (think of the door lock button on your car’s key fob, or perhaps its own cell phone or other receiver), or other set-off methods.  The main criteria of Trigger is that external stimulus is needed to set the bomb off.

There are combinations of Time and Trigger – the combinations are endless.

As radio amateurs we’re interested in the Trigger by Radio.  In the Boston case authorities feared/theorized that the cell phone network was a potential Trigger and for safety they shut it down.

In the videos released I didn’t spot any first responders, police, fire or security on radios, though it is unclear if radio silence was being enforced.

Often used in warfare, there are jamming countermeasures that might be deployed, which deny the use of the RF spectrum as a Trigger.  Some variations are intended to set off the RF based Trigger exploding a device from a stand-off situation.

The cowards who did the Boston bombings very likely may have controlled the bombs by cell phone.

In a situation like this bombing one has to reflect if keying up an HT is very smart – at least until the area is searched for additional devices & cleared.  If the enemy has left a tiered pattern of devices the RF from an HT may be the next device’s Trigger.

Temporary self imposed Radio Silence in High Risk Scenarios may be needed until the “all clear” is given.

“Certainly much more will come to light about the remote Cell Phone detonation of the devices, over the next few days and weeks.

Again our prayers and thoughts are with those killed and injured, and their families.



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The Ham Band releases “Seek You” on CD Baby

2012 has brought a new The Ham Band release “Seek You” (“CQ”) available for download.

The Ham Band -  Seek You -  CD Baby Cover

Click here for a Link to “The Ham Band” “Seek You” at CD Baby.




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REPOST: Another Nixie Clock Project – ArduiNIX

*** A friend had asked for copies of the Dekatron & Nixie Tube Posts***

***which seems a good excuse to repost them ***

ArduiNIX Demonstration from Flock of Butterflies

The last circuit boards have arrived and I am again experimenting with Nixie Tubes and Clock Making.

This project uses an ArduinoArduino Shield” and Display Board from ArduiNIX with the small IN-17 tubes providing the display.


Flock of Butterflies has a great series of articles on the ArduiNIX:


The ArduiNIX also has a forum at Robot Pirate’s:


I’ve covered writing about the Arduino “brain” before, but if you’d like to read more about this project the Main Arduino proge page is: http://www.arduino.cc/

I’m hoping to scale-up the display board for the larger IN-12 Tubes I would like to use, but first to get the clock running.



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