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2025-01-10

A different kind of Foxhunt

Suitable for the urban fox 

From the January-February 2025 SARC Communicator

If traditional foxhunts don't work well for your club or organization, this one might...

The last few months, I've been thinking about a different way to do a Foxhunt.  My vision was to have a Foxhunt available whenever you want, especially this time of year. Not everyone lives in town, and everyone's busy shopping and might not be able to dedicate an afternoon on a specific day for a group search. But what if the fox kept calling you out for a few minutes here and there, whenever you had a chance? No pressure, just try it out and see what you can find with your gear, experimenting with different antennas to get the best results. Go get that Fox!

Where to start with my build? You guessed it: Google and YouTube.  The first step was to make a Fox using things I had in my toolbox. I got a Baofeng radio, Arduino UNO, batteries, a waterproof box, and a Drok buck converter. Simple enough, right?

I first searched using Miss Google and came across this: https://www.hackster.io/nfarrier/auto-keyer-for-radio-fox-hunting-e89b99  "Cool, I can do this," I thought, so I did. After putting it all together, I programmed the Arduino UNO using the Arduino software with the code from that website. I set up the CW message, and everything tested just fine. My vision was starting to come true!

My power supply was an 18 volt 5.0 Ah Lithium-Ion Battery (Makita BL1850b) feeding in the Drok Buck Converter to reduce the voltage to 7.4 Volt for the Radio and that voltage was also perfect to feed the Arduino Uno as it has a 12 volt connection with its own regulator to supply 5 volt to the board.

Tested everything, and boy was this great! One watt output from the radio gave good range. I packaged it all up and headed outside. I found a good hiding place for the Fox, with easy access and safety in mind.

I could hear it from the east and west side of town. All was good darn... a few days later I couldn't hear it anymore until I was right beside it. I took the Fox home and discovered the TX (transmit) wasn't putting out power anymore, even though the battery was still good. My Fox SX5 Mosfet transistor must have failed. It must have been spending too much time in TX mode. So, I replaced the radio and changed the transmit message, reducing the time by almost 50 percent.


I put the Fox back in its den, and it was happy again, calling everyone to get searching. Darn... a few days went by, and once again, it stopped transmitting. I figured it must be the batteries. Out it came, and yes, the batteries were depleted. However, the Fox SX5 Mosfet transistor also failed again.

There goes the fox hunt, second radio blown. How disappointed you all would be!  I talked to a fellow ham about Baofeng radios. He uses them more often than me, and he showed me in the manual that the duty cycle is very small, 03/03/54 minutes (RX/TX/Standby). My fellow ham had a spare radio he wasn't using, so I bought it from him.

I did a few more programming changes to adjust the duty cycle.  I also decided to add "MORE POWER!" (à la Tim Allen)  So, I added a second Makita battery for a longer stay in the den.
I relocated the fox to be closer to home, just because I know I'll need to replace the batteries in a few days. For those of you in the area, I hope you all get a chance to find the Fox.

Happy Fox Hunting! 73,

~The Silver Fox VE3BQM


Hams meet Marines

A special event station from The Netherlands



This is an HF activity on January 23 from PA25MC, which will be on the air for just one day to introduce Marines to the world of ham radio. They will try to use as many HF-bands as possible on SSB. They remind us to please remember that Amateur procedures are new to them, but will do everything to get them up to speed quickly. 

Marines are used to speaking English but naturally keep their communications short. The organizers would really appreciate it if you contribute to a successful event by connecting with them!

PA25MC is organized and supported by PI4VBD, the club station of the Royal Army. Their station will always comply with the user regulations and regulations for radio amateurs and has no military function.


PI4VBD Royal Netherlands Army Signal Regiment on air 

QSL info for PZ5JT

Read carefully - send your card with return address, and without anything extra direct to:
PI4VBD / Verbindingsdienst,
Barchman Wuytierslaan 198, 
3818 LN Amersfoort, 
The Netherlands


~ Ton and Klaas-Jan
  John VE7TI

CQ CQ CQ

A different kind of Foxhunt

Suitable for the urban fox  From the January-February 2025 SARC Communicator If traditional foxhunts don't work well for your club or or...

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