What Was Different This Time?
So why do we think we can succeed this time after having failed to cross the Atlantic in the 1990s?
Well, we have several advantages this time...
First, the mode is much more sensitive. JT65B offers significant gain over a CW signal - more than 10 dB.
Moonbounce enthusiasts will attest to the advantage that JT65B offers. That by itself is a considerable improvement.
Second, this time we have a much better location. We are 550 kilometers closer to Europe. That means that more of Europe is in the footprint of any second hop propagation path that may exist, improving our chances of being heard and being worked. Finally, unlike our 1996 attempt, Newfoundland is not in the way!
The equipment is far better than what we had in 1996. The new ladder yagi has a much cleaner pattern, with more gain and improved front to back and front to side ratios. The use of Kevlar and intermediate support poles will reduce antenna movement in the wind, reducing "smearing of" the radiation pattern.
In 1996 we used a Hamtronics receive preamplifier. While reasonably good, it had less sensitivity (poorer S/N ratio) than the Landwehr preamps we have now. They have a noise figure of less than 0.4 dB, and the 17dB gain ensures that no signal is lost in the coax. Overall, they provide a measured 10 dB improvement in the signal to noise ratio over the receiver alone.
Our transceivers are more sensitive and stable (ovenized master oscillators) than the original ICOM IC-706 that we used in 1996. A post-transceiver high Q 2 meter bandpass filter will minimize extraneous signals.
As well, this time we will be able to transmit at 750 watts thanks to Warren, VO1KS and Paul, N1RJX, who have loaned the team a "lo lo" Larcan amplifier converted to 144 MHz. Originally used in television transmitters, the Larcan amplifier was designed to deliver 1 kilowatt indefinitely. Providing 750 watts, the maximum Canadian legal output, will be no problem for this expedition.
Here is a view of the Larcan amplifier that we will use. The underside of the circuit board is a massive heatsink. Two large fans, one of which is visible here, provide cooling airflow.
Of course, there have been big changes in the amateur radio world since 1996. Thanks to the popularity of multi-mode radios, there are now many more hams operating the weak signal modes on 2 meters. It is also much easier to inform those amateurs about this attempt. While we made strong efforts to notify European hams about our attempt in 1996, we were probably not able to get through to many. Through the miracle of the Internet however, that will not be a problem today. Anyone interested in updates will receive them in real time.
In 1996 we had to monitor the white noise emanating from a speaker for a solid week. A moment's inattention could have resulted in a missed opportunity, and trust us, there were many numerous moments of inattention. It is simply unavoidable. With the digital modes such as JT65B however, we have the ability to scroll back and review previous data to confirm the presence of a signal. The actual raw data will be saved to a hard drive, permitting us to conduct a post-expedition analysis of the received signals. More importantly, that raw data will serve to confirm our claims of success.