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:

80m elevation pattern
80m azimuth pattern
80m SWR Graph
80m 3-D Antenna Pattern
  160 Meter Inverted-L:

160m elevation pattern
160m azimuth pattern
  600 Meter Inverted-L:

600m elevation pattern
600m azimuth pattern
EzNec model results:
Z = 0.81 - j681.5, 1.7 dB antenna directivity.

  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:































 
  Return to Home Page