Steve's, VE7SL signal as received here June 23rd, 2007 using Argo software.
View of antenna layout
The 137 KHz Loading Coil
The original loading coil had taps at the bottom but were later replaced with a pair of computer flyback cores with 16T #16 en on the secondary and 10T #14 stranded (PVC) over top on the secondary, then wrapped with HV tape. The core was initially wrapped with a couple of layers of HV white electrical tape 3M PN 69. The top of the flyback secondary winding goes to the bottom of the big coil. The bottom of the primary was connected to the braid of the RG8-X coax but not earth ground. The bottom of the secondary was connected to earth ground consisting of two 5' copper rods a few feet apart. As well, a few wires leading from the rods and buried just below the ground surface in the back yard. In addition, a heavy copper wire is also connected to the rods and runs back several feet to another ground rod buried at the bottom of a creek. For the loading coil, I chose a 320mm (12.5") dia form used for sewer applications. In the first attempt at matching, the bottom portion of the coil had taps every ~2 turns for impedance matching to 50 ohms, but is now replaced with a pair of flyback cores. For fine tuning the larger coil, a variometer was installed inside the centre of the coil. The variometer had two coils in series, each having 33 turns and wound on a standard 4" dia PVC form, 10" long. The variometer either adds or cancels some of the inductance to the antenna. At present, this variometer can be adjusted by remote control from the shack using a motor drive mounted on the outside of the larger coil. Initially the large coil had two sections each having 78.5 turns, for a total of 157 turns of #14 AWG enamel wire, which later turned out to be too many turns and I actually only needed ~104 turns, this gave me the best resonance for ~137 kHz. The large coil was wound on a 990mm (39") long form. Each turn was spaced 3mm centre to centre using cotton string. The spacing was to reduce the chance of arcing between turns as well increase the Q of the coil. After completion of the winding of both coils, three coatings of an exterior Varathane was added to eliminate any absorption of the cotton to moisture. The large coil was later covered by a blue PVC barrel to protect it from the weather. Don't use the black ones as they contain too much carbon and are too lossy.