Beacon

Welcome to the KC0JCA Beacon Page!

The whole beacon runs 24/7 broadcasting my callsign every 5 seconds at 13 WPM.  The whole beacon is powered by a 100 W solar panel connected to a deep cycle lead-acid battery.

Transmitter

PROJECT TANGO 

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Transmitter is a Hendricks QRP Tayloe Simple Transmitter (TST) running at 4 Watts.  Built-in keyer prevents key down longer than 7 seconds, so it runs at a power amplifier efficiency: ~70%.  This allows the 2N7000 finals to stay relatively cool in a TO-92 plastic package.  This transmitter was built from a kit from http://www.qrpkits.com/tst.html

(Note: 6/16 Due to frequency drift caused by temperature fluctuations, the transmitter is forced-air cooled by a 0.5W  brush-less cooling fan salvaged from a PC power supply.)  The transmitter uses approximately ~350 mA.

On Air: 16 January 2015 – Current

Keyer

The keyer is a PicoKeyer Plus from N0XAS.  Assembly was simple, but programming it was not.  My CW skills were a little rusty but it slowly came back.  You have to program it using code using a paddle.  Being that I am a straight key person, I did not have access to one.  With advice from Doug at Gateway I took a 3-wire stereo plug and soldered a SPDT switch onto it. BOOM! a paddle!  After programming it, it was easy to plug into the transmitter.  I chose D Cells because I was curious to see how long D cells would last on the keyer.  I buy batteries from Dollar Tree so cost isn’t a problem.  I may add the included zener diode and put it into the battery.  The total cost of the keyer was 17.99 plus shipping.

Antenna

Pretty simple, a half-wave dipole pointing north-south up 15 feet in the air.  I have built these things so often that it only took 10 minutes to build and another 10 to set it up.

Power

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Renogy 100W mono-crystalline Solar Panel (R). It is connected to charge controller which handles my solar cell and 12 volt battery system.  The panel supplies 22 volts of 100 watt power (~4 AMPS) to a CMG-2420 charge controller and a deep cycle cell battery.  The beacon itself is tied into the load circuit using a 1 Amp fuse in the unlikely event of a power surge.  The power system powers my ham station as well as my work bench (meter, oscilloscope, and soldering iron) using a 1kW inverter attached to the battery. I have on the grid power available, but I don’t remember when I plugged it in last.  The old  poly-crystalline solar panel(L)  supplied ~480 mA, but efficiency dropped significantly after 8 years to less than 300.

CMG-2420 20A charge controller

Purpose

The whole reason for this beacon project was to see if I could make and operate a beacon from scratch with the minimum amount of money and resources available.  This project brings together my love of electronics tinkering, 10 meters, solar energy, and QRP.  I could have modified an old CB radio to use, but I wanted to keep it simple, and minimize its impact on the environment.

PREVIOUS BEACONS

Old Beacon (PROJECT LAIKA) IN RESERVE

Transmitter

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The forced air-cooled trasnmitter is a Hendricks kit kindly supplied by KJ4VYI to replace the old board.  It is driven by a 2N3553 transistor. The circuit uses a JFET VXO (variable crystal oscillator), driver stage and PA stage that’s capable of producing almost 2 Watts of power.

On Air:  16 November 2014 – 16 January 2015

Old Beacon (PROJECT TENER) Decommissioned

If you are on this page, chances are that you have heard it on the air!  This is the result of a good year of planning, building, and testing the transmitter, keyer, and dipole.

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Transmitter

The  previous Transmitter was a modified Pierce Oscillator using a 28.224 MHz crystal and one NPN transistor.  The variable capacitor \”bends\” the crystal to its current spot at 28.2252 MHz.  I chose this design because it only has 11 total components and a reputation for low-power consumption and reliability.  The RF transistor is a 2N3553,  The 2 coils are wound using #24 wire around a Amidon T37-2. I found the schematics in an old CQ magazine and had the board custom made by FAR circuits.  Construction was simple, with most of the difficulty in acquiring a suitable crystal for operating on the 10 beacon sub-band, and the Amidon core.  The core wasn’t stocked by Gateway Electronics and had to be special ordered.  Once the transmitter was completed, I had to search for a suitable keyer.  This design lasted for 1 year and 2 months of continuous operation until a lightning storm knocked it out.

On Air:   24 July 2013 – 15 August 2014

Have any comments or want a copy of the schematics?  Please send me a comment!