ARRL

News

Spring 2008 W1AW Frequency Measuring Test Scheduled for May

04/30/2008

Capitalizing on the popular and effective automated online results reporting system developed by Bruce Horn, WA7BNM, for the Frequency Measuring Test (FMT) in November 2007, W1AW will conduct a spring FMT. This FMT will begin on Wednesday, May 21 at 9:45 PM (EDT) (that's the same as 0145 UTC on May 22), replacing W1AW's normally scheduled phone bulletin. W1AW Station Manager Joe Carcia, NJ1Q, recommends that those planning to participate should listen to W1AW transmissions prior to the event to determine which band -- or bands -- will be best for measurement purposes.

In this edition of the FMT, listeners will be asked to measure the frequency of an audio tone, given an exact frequency for the carrier signal. The tone will be between 1000-2500 Hz. The carrier frequencies will be 3990 kHz (LSB), 7290 kHz (LSB), 14290 kHz (USB) and 18160 kHz (USB).

Measuring audio frequencies of a modulated signal is a useful skill for those interested in digital modes. Proper tuning of these signals is important to obtain the highest quality performance. For non-digital users, it is also important to understand the relationship between the frequencies of the modulated signal's sidebands and its carrier. The techniques for measuring a modulating tone are described in the November 2004 QST in an article on the Frequency Measuring Test by H. Ward Silver, N0AX. The FMT Web page also has several interesting articles about measuring on-the-air signal frequencies.

The FMT will start with a general QST call from W1AW at exactly 0145 UTC, transmitted simultaneously on the frequencies listed above. The test will consist of three 60-second key down transmissions for each band, followed by a station identification. The test will last for approximately 15 minutes and will end with station identification. W1AW will identify before, during and after the transmissions. There are no plans at this time for a West Coast station.

Submitting Reports

As in the November 2007 FMT, your report should be submitted via the FMT Report form on the W1AW FMT Web site. Along with your call sign and e-mail address, enter your most accurate measurement on each band. There will be a window to list your equipment, describe the method you used to make the measurements and enter any Soapbox comments. Participants have 14 days to input their data. Participants may input their data more than once, although the final entry will be the one used for the results. W1AW will post the transmitted frequencies on the FMT Web site following the test. This will allow participants to quickly determine the accuracy of their equipment and methods. A complete package of results will be available via the FMT Web site after the 14-day reporting period is concluded. The results from the November 2007 FMT are available on the 2007 FMT Results Web site.



Back