While I was including a gray line image to this website (no longer available) I thought of a contact I made many years ago with a couple of stations that were in the Montreal area. The gray line may or may not have had anything to do with the propagation. The initial contact was with Mike VE2DQO and Mel VE2DC on 10 meter SSB. Signals were very strong. The contact I believe was in 1980 but unfortunately I have misplaced the log for that period.
I happened to have a signal generator in the Ham shack at the time or more precisely a Motorola R-1200 service monitor. I wanted to find out if the signal generator could be heard in Montreal on 10 meters, a distance of 1875 miles (3017 km). The initial level of the signal generator was set to +13 dBm or 0.020 Watts. I connected the generator to the antenna and attempted to send a series of V’s by connecting and disconnecting the BNC connector going to the generator. The first report I received was from Mike and was an S7. That’s 93750 miles per Watt! Consider S7 as a relative level not as an absolute indication of signal strength. I systematically reduced the level of the signal generator until the signal finally disappeared. The signal disappeared somewhat earlier at Mike's location as compared to Mel’s location. Mel finally lost the signal at about –20 dBm. That is 10 microWatts (0.00001 Watts). With the signal still discernible at –18 dBm or 0.0000158 Watts transmit power; the miles per Watt equaled 118.67 million!
The antenna at this end was a Mosley TA33jr at about 50 feet (15m). VE2DQO used a Mosley TA36 also at about 50 feet. I don’t recall what VE2DC used but it was a big antenna well over 100’ AGL. I will include more details when I find the misplaced log.
UPDATE: June 10, 2007
I found the log. The contact was made on November 8, 1981 between 2200 & 2250 UTC on 28.295 MHz. According to the log the signal was still detectable at Mel's location with -20 dBm (0.00001 Watts) signal generator output power.