mrcampbell / February 17, 2017 / KM2ARC

October Amateur Radio Club Update

Amateur radio club is off to a great start this year.  We have a core group of students preparing to get their technician class license.  After a couple of meetings of reviewing materials to prepare for the exam we stepped into the radio shack and got some air time.

Members of the club stepped into the radio room last week and went on the air as KM2ARC – our FCC assigned call sign and spoke with other friendly amateur radio operators through a local repeater.  One operator was headed home from New York City and the other was located an the North Shore.  These experiences help students get over their “mic fright” and comfortable speaking to others on the radio.

Next week, From Monday, October 17, 2016 through Friday, October 21, 2016, is the School Club Roundup. The School Club Roundup is an event where schools all over the country will be on the air trying to make contact with one another and other amateur radio operators. We hope to have participation from many students at Kellenberg. You don’t have to be a member of our radio club to try getting on the air and making some contacts.  The more students helping out the more chances we will have at making contact with other schools around the country.  Any student wishing to participate please see Mr. Campbell.

mrcampbell / October 14, 2016 / KM2ARC

mrcampbell / September 23, 2016 / KM2ARC, Radio News

Welcome Back!!

The 2016-2017 school year has begun!  We will hold our first meetings of the school year as follows:

Computer Club will meet on Tuesday 9/13/2016 at 3:15 in the library conference room.

Amateur Radio Club will meet on Thursday 9/15/2016 in the library conference room.

If you would like to sign up for either club and can’t make either of those meetings, please see Mr. Campbell by Friday 9/16/2016.  You will need to attend meetings and participate in club activities to receive credit for these clubs.

 

mrcampbell / September 10, 2016 / Computer Club, KM2ARC

Arduino to detect Valid Audio from Bridgecom Repeater

We are using a Bridgecom Repeater that we wanted to try linking to another site.  Based on the documentation we used the DB25 port on the back of the repeater to get audio in, audio out and trigger the PTT through use of a Signalink  USB.  We found out that the repeater audio output emits all audio regardless of whether or not it had a valid PL tone (CTCSS).

Pin 17 of the DB25 port of the repeater is documented as COS (Carrier Operated Switch).  We found that the pin outputs random voltages until a valid signal is detected at which point the voltage drops to zero.  Using analog pin 0 of the Arduino we read the voltage.  Once the voltage is 0 we turn on the relay which causes audio to pass through to the Signalink.

Here is a diagram of our wiring:

Bridgecom Repeater COS Detector

Click on image to enlarge.

 

Below is the code we are currently running to implement this operation:


//Connect pin A0 to Pin 17 on repeater
//Connect Ground of arduino to ground of repeater
//When sensor is 0 key radio

const int analogInPin = A0; // This is the COS output on the repeater.
int sensorValue = 0; // value read from the pot

const int relayPin = 2; //This relay is used to connect the audio output of the repeater to
//Audio input on the computer.

void setup() {
     // initialize serial communications at 9600 bps:
     Serial.begin(9600); //We will use the serial line to debug this program
     pinMode(relayPin, OUTPUT); // set pin as an output
}

void loop() {
     // read the analog in value:
     sensorValue = analogRead(analogInPin);
     // map it to the range of the analog out:
     // change the analog out value:

     Serial.print("sensor = ");
     Serial.println(sensorValue);
     if (sensorValue==0){ //When the value goes to 0 that means a valid signal is detected.
     
          Serial.println("Relay On");
          digitalWrite(relayPin, HIGH); // turn the relay on
     
          do{ //Keep the relay on until the the COS is not 0
               delay(500);
          }while(analogRead(analogInPin)==0);
     
     }
     digitalWrite(relayPin, LOW); // turn the relay off
     delay(2);
}

 

mrcampbell / July 20, 2016 / Computer Club, KM2ARC

mrcampbell / May 11, 2016 / KM2ARC

National Parks On The Air

National Parks On The Air

Throughout 2016, Amateur Radio will be helping the National Park
Service celebrate the 100th anniversary. Hams from across the country
will activate NPS units, promote the National Parks Service and
showcase amateur radio to the public. For more information go to ..
http://www.arrl.org/NPOTA

mrcampbell / February 22, 2016 / KM2ARC, Radio News

Local Ham Fest – February 28, 2016

LIMARC Hamfest

LIMARC (The Long Island Mobile Amateur Radio Club) will hosting a hamfest at Levittown Hall on
Sunday, February 28, 2016. Doors open at 9:00 A.M.  Admission is $6.00 per person.  You will find all sorts of assorted items related to amateur radio.  There will also be a VE session at 10:00 AM for those looking to get licensed or upgrade their license.

Want to learn more about Software Defined Radio, there will be a presentation at 11:00 AM.

Levitown hall is located at 201 Levittown Parkway, Hicksville, NY 11801

mrcampbell / February 19, 2016 / Radio News