KL7UW

600 METER PROJECT


  
  July 28, 2009: KL7UW was added as WD2XSH/45 to the "500-KHz Experimental Group"
 
  I am getting started setting up a station for 500-KHz (600m) Experimental Group (WD2XSH) and looking at low-noise 
  receiving antennas to use with my SDR to monitor the band.  A Beverage would be 900-foot long which exceeds my
  property boundaries.  My neighbor has given permission to run the Beverage parallel to his north-south private aircraft runway.

  • Here are photos of the BOG couplers:
  • Screen capture of 508.6 KHz on Oct. 20, 2009:
  • Screen capture of 509.6 KHz on Nov. 05, 2009, 450-foot BOG:
  • Screen Capture of 509.6 KHz on Nov. 05, 2009, Inverted-L: bottom is BOG, top is INVL, center is before gain adjustment
  • Screen Capture of 509.6 KHz with 4-KHz span:
  • Screen capture of 508.6 KHz showing WD2XSH/20 CW signal
I am also considering a large square multi-turn loop. For more information on the ARRL 500-KHz Project read the article in the July/August-2007 issue of QEX and recent news published on the ARRL Website. Below is a drawing showing the proposed transmiting antenna: November 1, 2009: The Inverted-L antenna was raised! The antenna has two wires instead of three for the 130-foot top-hat. The vertical wires are 39.5 feet long with 2.5 feet separating both top and bottom from their supports. Some photos: Here is the NEC4win95 antenna analysis of the antenna: 80 Meter Half Square: 160 Meter Inverted-L: 600 Meter Inverted-L: See the N3ZI DDS-VFO 500-KHz prototype. Here is a link to the MFJ-269B modification to 500-KHz. The prospective Transmitter is a surplus NDB unit made by Soutern Avionics Co., model SS-800A, rated for 50w CW, 100w PEP. Testing with 0.1 Vrms drive from the DDS VFO produces a maximum output of 1.4 RF amps into 50-ohm termination (100w). My Bird-43 power meter reads 68w using a 100w HF element (100H). This element is derated by 3-dB at 500-KHz. Here is a block diagram and some photos: March 3, 2010: An Elecraft K3/10 HF transceiver was ordered. The K3 will operate on 490-510-KHz at 0.1 mw by use of the General coverage filter unit and transceiver interface to bypass 160m high-pass fliter. This will enable running CW, QRSS, PSK, MSK, and WSPR modes on 600m band. The K3 will be able to drive the NDB transmitter as a linear amplifier up to 100w. Feb. 9, 2010: Building coil forms made from white plastic food carving board; Coil winder rig:
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