[600MRG] Eprobe test results

[Larry]

Due to some problems with the laptop used for the "backup station", less 
data was acquired than I had hoped for in this initial test run. There 
may be some minor accuracy discrepancies due to this, but I am sure the 
overall trend is correct.

Most of the data is for the period between 0300Z and 0630Z on the 19th. 
The data will be presented first, followed by test details and observations.

Total # of stations decoded:
Eprobe = 4
BOG    = 9

# of spots during test period:

          Eprobe  BOG
WG2XXM     42     44
WG2XIQ     10     22
WH2XND     30     33
WG2XSV      9     14


Average WSPR reported S/N for above spots:

            Eprobe     BOG     Difference
WG2XXM     -16.2      -3.5        12.7
WG2XIQ     -24.9     -12.5        12.4
WH2XND      -8.4      -1.8         6.6
WG2XSV     -17.2      -12.9        4.3


Signal levels during the selected test period were strong and mostly 
stable. The difference between the BOG and Eprobe were less during this 
period than earlier when the band was in transition. When conditions 
were marginal, the Eprobe was pretty much useless.

The BOG is 600' and pointed due East. It is known to have at least 6 dB 
F/B with a typical cardioid pattern (more or less). The feedpoint is 
about 200' from the shack.

The Eprobe is a PA0RDt type with a 4' stainless steel whip and is 
mounted on my test stand about 6' above ground. It is positioned in the 
yard roughly 30' from the shack.

There were no IMD issues observed with this Eprobe, however, external 
isolation of both the feed line and power supply were in place providing 
much more common mode /ground loop rejection then most Eprobe installations.

Even with the additional isolation in place, the Eprobe was highly 
susceptible to "local" noise. It was necessary to turn off several 
fluorescent lights in the house and shop in order to hear any signals at 
all. These lights are normally on when using my other RX antennas.

The main station (TS-590) and the backup station (IC-706 and HB xvtr) 
are known to be equal in decoding WSPR signals when used on the same 
antenna.

My intent is to build and test additional Eprobes as time and 
opportunity present. The BOG and other Beverages will be rolled up soon 
when farming starts in the field and the Eprobes will be tested against 
my "summer" RX antennas after that happens.

73,

Larry - W7IUV / WH2XGP