N4MW Project: GPS Locked Beacons


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Click for technical details of beacons

The N4MW/B Memphis area (EM55) beacons operated on all eleven bands from 10 meters to 10 GHz for several years until 1994, when I relocated to New Kent, VA (FM17kn). Additional technical information on the Memphis beacons can be found in chapter 3-1 of the ARRL UHF Projects Handbook.  

The beacons described here are operated from FM17kn, central Virginia.  Synthesizers are used to lock all frequencies to GPS.  Frequency accuracy has been verified by K3CB using a Cesium standard. Modulation is on-off keying (CW) with identification in 15 word per minute Morse code: N4MW/B FM17KN (15 second dash), repeating about twice per minute.

In Virginia since 1995, I have primarily operated a two meter beacon, later adding a 10 GHz FSK transmitter.   In June 2009 the two meter beacon was upgraded to GPS frequency lock. 10 GHz was also changed from FSK to CW and upgraded with GPS frequency lock in August 2009.  I plan to add bands, establishing xxxx.280 as the standard frequency on all bands 33 cm and up. 222 went on the air in September 2009, 1296 in November 2009, 432 and 903 in  December 2009 and 2304 in March 2010.  903 and 1296 and 2304 are on the air temporarily using yagis pointed 30 degrees until omni antennas are installed. Revised 1 May 2010.

 

 More Technical details AN FSK Beacon Demonstration
SEVHFS Conference Paper SEVHFS PPT Slides (19 MB)

Report reception to N4MW

28.250

Inactive

Deferred to WA4FC/B operation.

50.070

Inactive

Deferred to WA4FC/B operation. See also  W4HHK/B in EM55db

144.280

Active

5 watts CW to Sqloop at 90 feet. Frequently heard in the northeastern states, heard in EM00 (TX) on Es.

222.060

Active

15 watts CW to Sqloop at 90 feet. Reported heard by K1RZ in FM19jh.  Frequency confirmed +/- 0.01 Hz by KE2N.

432.300

Active

50 watts CW to Sqloop at 90 feet. Reported heard by K3CB and WB3IGR.

903.280

Active

50 watts CW to yagi pointed 30 degrees. Omni antenna planned.

1296.280

Active

6 watts CW to yagi pointed 30 degrees. Omni antenna planned. Heard by K3CB, W3FEY, and WA2LTM.

Click here to hear K3CB southern MD reception of 1/16/2010.

2304.280

Active

4 watts CW to WA5VJB log periodic pointed 30 degrees. Omni antenna planned. 

Click here to hear K3CB southern MD reception of 4/2/2010.

3456.280

Inactive

TBD

5760.280

Inactive

TBD

10368.280

Active

1.5 watts CW to waveguide slot at 95 feet Actual frequency 10368.2799974 ( 2.6 Hz below the target frequency).

Click here to hear K3CB southern MD reception of 3/20/2010.

24192.280

Inactive

TBD

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