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September Fox Hunt

The month of September there will be two SFARC FOX Hunt opportunities!

The first Fox Hunt will be Saturday September 20 at a special location; Stampede Reservoir off of Highway 80 just east of Truckee CA.  This Fox Hunt is scheduled to coordinate with the SFARC annual campout at Stampede September 18 through 21. The Fox Hunt will start with a pre-meeting at the camp host’s (base camp site, Site 228), starting after the morning breakfast, usually no earlier than about 10 AM.

If you are not planning to campout at Stampede, then consider coming up for the breakfast (don’t forget to RSVP), stay for the day joining the Fox Hunt later in the morning, enjoy all the afternoon fun events, and then savor the Saturday night dinner (again, please don’t forget to RSVP).  Stampede is actually a reasonable drive from most Sacramento areas…less than two hours with normal traffic. Additional information on the SFARC campout, including directions, daily activities, how to RSVP for meals, etc. are on the Club website under “Activities/Fall Campout”.

Brian AI6US will be the Fox Tender for the Stampede Fox Hunt.  Thank you Brian.  The simplex frequency for the SFARC campout, campground, will be 147.555/PL 100.0, which will also be tied into the W6EK repeater via ASL.

The second Fox Hunt opportunity will be the regular September Fox Hunt on the last Saturday of the month, September 27.  Thank you Frank KG9M for volunteering to be the Fox Tender for this Fox Hunt. Regular pre-meeting time of 9 PM directly following the monthly club breakfast in the parking lot of Wings following the SFARC monthly breakfast.  More details to follow in the next few weeks.

73 and enjoyable hunting.
Greydon KC6SLE

The Loss of an SFARC Friend

It’s with great sadness that we share the news of another SK. Bill Silva aka. “Colusa Bill” (KA6FKK) passed away on September 20th due to complications from a stroke.

From dialing around 40M and landing on that BIG voice to hearing him participate on nearly all of our nets including the Coffee Break, Given the distance, and being the sole caretaker of his mom, it was hard for Bill to attend many events but he did make a special trip to Hamfest last March to meet Brian and Smitty; it was great to put a face with the voice. 🙂

Bill’s voice, laugh, and calm demeanor will certainly be missed.  As we learn more about his celebration of life, we’ll make sure to share it here.

73 one last time old friend, W6EK

Running A Fox Hunt

Being the Fox Tender is almost as much fun as finding the Fox!

As the club’s RDF abilities improve the creativity in where the Fox  is hidden will likely become equally creative! If you have ideas on challenging the Fox Hunters then SIGN UP!

The Process

  1. Complete the sign-up form
  2. Once confirmed on the calendar arrange to pick up the Foxes from Doug (W2VX)
  3. Select an area to hide the Fox and do some basic testing (to understand coverage area)
  4. Promote the Fox Hunt (Coffee Break Net, Club Calendar, Club announcements i.e. Watts Up)
  5. Run the Fox Hunt and record results and take pictures if you are able
  6. After the hunt return the Foxes to Doug (W2VX)
  7. Write an article for the Club Newsletter!

Available Foxes

The club (Doug – W2VX) maintains several Foxes for Fox Tenders to use. The foxes are pre-programmed and ready to go with the exception of potentially needing new batteries. The available foxes include:

Doug (W2VX) has constructed a high power fox placed in an ammo can. Given the high power output (1-5 watts) this Fox would is most appropriate for longer distance Fox Hunts.

Jon (KI6RT)’s Byonics MicroFox 15 is typically available for club fox hunts (depending on what KI6RT is testing). Others in the club also own this model micro fox.

Foxes from Byonics typically output 15 milliWatts and are useful in parks or smaller areas.

SFARC owns two Byonics MicroFox 15S transmitters.

More questions? Please contact Jon (KI6RT) or Doug (W2VX).

Fox Hunting Equipment

The popular RDF (radio direction finder) techniques used by SFARC include:

  • A version of the Handi-Finder created by Doug (W2VX) and Greydon (KC6SLE). This device switches between two dipole antennas effectively measuring the TOA (time of arrival) that appears as a tone on the HT (handi-talkie). As illustrated on the right the tone will be null (i.e. minimum volume) when the antennas are equidistance from the hidden transmitter thereby providing a vector to/from the hidden transmitter. Once several bearings or vectors have been established and plotted on a map the location of the Fox can be estimated. Mike (K6YMM) presentation on the technique can be found here.
  • Growing in popularity is the Tape Measure Yagi with a variable attenuator (step attenuator or an offset attenuator). The directional nature of a Yagi enables hunters to point straight at the hidden transmitter. As the the Fox Hunter approaches the Fox, attenuation is required (otherwise the HT will be overloaded and the S-meter will not show a peak).
  • The club continues to explore other RDF technologies. Most recently testing the KrakenSDR which uses five coherent receivers feeding data into a RaspberryPI running the MUSIC (MUtiple SIgnal Classification) algorithm. MUSIC is able to estimate DOA (direction of arrival) and together with a android phone displays a heat map and a vector straight to the hidden transmitter!