Project Build – Tape Measure Yagi (Front Page Promo)
Due to overwhelming demand, reservations are closed for the 2-meter tape measure yagi project build on Saturday, March 25th.
It’s common for people to drop out so if you’re interested, please add your name to the waiting list.
CLICK HERE
March Project Build (Read More)
RESERVATIONS CLOSED – FULL
The build will be at the Crossroads Church Gym starting promptly at 9:30 AM, and running no later than 1:00 PM. It will include a brief test and usage following the build.
The cost is $26 and includes everything needed to construct and complete it. It will be both an RX and TX antenna and useful for many things including field use and RDF.
If you’re interested in joining the waiting list, please submit your reservation below:
February 2023 Newsletter
Hams In The Snow
In case you missed it in this week’s “Watts Up At SFARC”
To All Hams (hoping to get) In The Hills,
This Saturday we’re going to do a impromptu snow run for anyone interested. We will meet at Mar-Val’s grocery in Georgetown, Saturday (February 4) at 0800. We will head east on Wentworth Springs Road and see how far Paul (W2OHV) can go and how many of us need to be pulled out.
Bring lunch and a camp chair.
A recovery point on your vehicle would be good but you can count your receiver hitch as a recovery point. Be able to remove the ball from your hitch, if needed.
Classes/Training Tech Class ’23 (Page)
The Sierra Foothills ARC offers all levels of amateur radio license upgrade classes.
Course fees include the latest version of the applicable ARRL license manual shipped to your home and hands-on lab materials. FCC exam fees are not included. All classes are held online via a Zoom classroom. The class also includes two (2) in-person labs held in the Auburn, California, area. The first lab focuses on a license-appropriate Get On The Air (GOTA) skills session. In the second lab, we will explore building your very own antennas. Labs are not required.
The next class offered by SFARC will be the Amateur Radio Technician License class. This is the entry-level first in a series of classes. Classes will start April 25th, 2023, and run 6 weeks. Each class will be held Tuesday evenings from 19:00 – 21:00 PST via Zoom.
Our 2023 Class Calendar:
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- Technician – April 25 – May 30, 2023
- General – August 8 – September 26, 2023
- Technician – October 17 – November 28, 2023
Ready to enroll in either of the upcoming Tech classes?
Click SELECT OPTIONS below.
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Want to pre-enroll in the General class starting on August 8th, reserve your spot today.
Click SELECT OPTIONS below.
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We Need Your Help (Front Page Promo)
It’s a new year and WE NEED YOUR HELP. If you’ve been thinking about how to get more involved with SFARC, now’s your chance. We’re looking for the following positions:
- Field Day Chairs
- Picnic Chair
Interested in learning more about the roles, CLICK HERE to send us a message.
January 2023 Newsletter
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
- Complete the sign-up form
- Once confirmed on the calendar arrange to pick up the Foxes from Doug (W2VX)
- Select an area to hide the Fox and do some basic testing (to understand coverage area)
- Promote the Fox Hunt (Coffee Break Net, Club Calendar, Club announcements i.e. Watts Up)
- Run the Fox Hunt and record results and take pictures if you are able
- After the hunt return the Foxes to Doug (W2VX)
- 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!
