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Fall Frequency Measuring Test This Month

11/02/2009

The W1AW Frequency Measuring Test (FMT) has taken several different formats over the past few years. This year, we return to the "classic" FMT -- measuring the frequency of an unmodulated carrier. Accurate frequency measurement is required of all hams for both regulatory compliance -- "stay in the band!" -- and operating convenience, particularly on the new digital modes. The W1AW FMT will run on November 12, 2009 at 0245 UTC (this is Wednesday evening, November 11, 2009 at 9:45 PM EST). It will replace any W1AW bulletin normally scheduled for that time. It is recommended that participants listen to W1AW's transmissions prior to the event to get an idea of conditions to see which band (or bands) will be best for measurement purposes.

The basic techniques for making carrier frequency measurements are the same as described back the October 2002 issue of QST. According to QST Contributing Editor H. Ward Silver, N0AX, you don't need a basement full of sophisticated lab equipment to make a surprisingly accurate measurement. "The frequency accuracy of most radios sold in the past decade is specified as ±10 ppm or better," he explained. "By calibrating your radio to a known frequency reference such as WWV or CHU and letting it reach an even, stable temperature, your measurements can be within 1 ppm or even better." The 2006 FMT announcement includes a sidebar on calibrating your receiver to an over-the-air frequency reference.

Format and Schedule

The FMT will begin with a general W1AW (QST) call beginning exactly at 0245 UTC sent simultaneously on two amateur frequencies. The test will consist of 20 second key-down transmissions, followed by a series of Vs, followed by station identification. W1AW will identify before, during and after the transmissions. The test will last for a period of approximately 5 minutes total. The approximate frequencies for the carriers will be as follows: 80 meters near 3597 kHz and 40 meters near 7097 kHz

Thanks to volunteer Mike Fahmie, WA6ZTY, a 40 meter-only West Coast run will follow the W1AW transmissions by 15 minutes, beginning at 0300 UTC and will follow the same format as W1AW. The approximate frequency will be 7096 kHz.

Connie Marshall, K5CM, in Oklahoma will make additional transmissions on 160 and 80 meters following the transmissions of West Coast station WA6ZTY, at approximately 0315 UTC. The approximate frequencies for the carriers will be as follows: 160 meters near 1845 kHz and 80 meters near 3578 kHz. According to W1AW Station Manager Joe Carcia, NJ1Q, K5CM's central location should provide a much stronger signal in mid-continental areas.

All transmissions -- no matter which station they originate from -- will consist of a call-up/QST transmission lasting for approximately 3 minutes, followed by three 20-second key-down periods of unmodulated carrier.

Reporting and Results

Your report should be submitted via the FMT Report form on the FMT Reporting and FMT Results Web site no later than 2359 UTC on November 15. Along with your call sign and e-mail address, enter your most accurate frequency measurements on each band and indicate whether you measured the W1AW, WA6ZTY or K5CM's signal. There will be a window to list your equipment, describe the method you used to make the measurements and enter any Soapbox comments. After the entry page has been closed, the Web site will then automatically calculate the measurement error of each report and display the actual transmission frequencies. The information entered by each reporting station will also be displayed as in previous FMTs. (The results for recent FMTs are on the W1AW FMT page.)



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