One afternoon, we noticed that 146.76/.16 MHz machine was timed out and thus unusable. It was timed out because there was a continuous unmodulated signal on the (146.160 MHz) input (we think from somebody’s stuck-on transmitter) which caused the 146.76 controller to do its thing and shut down the output.
Jim Pliett, K9OMA was able to detect the signal on the input using a pair of phased yagis at the top of his tower at his QTH up near Churubusco, and he was able to get a solid bearing on the source which pointed down through the center of Ft. Wayne. We wanted to get a few more bearings from other hams in the area so that we could radio direction find (RDF), i.e., triangulate the source and localize it. I was frustrated to realize that we didn’t know who else in the area were set up with rotatable yagis on their towers.
As a result of this experience Jim and I decided to organize a cadre of hams in the Ft. Wayne/Allen County area who had the appropriate equipment at their QTH that would allow us to RDF a signal source should a similar problem arise in the future. So I’m requesting volunteers who would be willing to serve on an RDF team.
The idea of the RDF team is to have at hand a list of local hams who we can call when necessary and have them take a bearing on a problem signal source and report the bearing to me, or Jim, (or whoever is acting as the RDF coordinator). With sufficient cross bearings we can then localize the source of the signal and subsequently find it’s exact location just like we do when we Foxhunt.
So if you’re willing to participate as a member of the proposed RDF team, I need the following information:
- Telephone Number.
- Type of antenna (model number or band(s), i.e. vhf,uhf, number of elements).
- Antenna height above ground.
- Bearing resolution (some rotors are continuous, some increment by 10 degrees, etc.).
- Method of determining signal strength (Analog S-meter, bar meter, etc.).
- Times of day when you are typically available and would be able to participate including weekends if availability is different from that on weekdays.
Once we have a list of participants we would plan to run a few tests, probably coordinating on the 146.76 machine where we would have folks bring a test signal up from known location(s) and have everyone on the team take a bearing on it and report said bearing to the coordinator. That would give us practice taking bearings and transferring data, and would also give us the opportunity to calibrate the bearing readings on each team member’s system thus allowing us to compensate for bore-sighting errors.
So if you’re interested in supporting the Allen County DF team, call Al Burke, WB9SSE at 260-637-1989, send email to email@example.com and provide the data mentioned above.