Mars2009

Editor's Notes

• #5: Fort Huachuca (pronounced Wha-choo-ka), or as some people call it Fort “Hoochie Coochie”.
• #9: Customers include, Department of Defense, Department of the Army, Department of the Navy, both Navy and US Marine Corps, Department of the Air Force, US Coast Guard, Department of State, National Disaster Medical Service, Department of Homeland Security, both FEMA and TSA, the National Communications System, which includes shares as well as offering support to state and local emergency response agencies and certain private agencies such as the American Red Cross
• #16: If we look at the radio spectrum, the MARS frequencies go all the way from MF through all of HF, that is, 2MHz to 30MHz. Let’s look at just the HF spectrum from this chart,which is highlighted in the third row here.
• #17: If we focus on the HF spectrum, we see that the frequencies as shown here, we note that the MARS frequencies, which are fixed singled frequencies inside the Red areas are always outside the amateur frequencies, which are shown in green. Sometimes these are a long way outside, but often they are close enough to let amateur equipment such as linear amplifiers to be used with little or no modification.
• #20: What this slide shows is how an antenna needs very little trimming for a height of 0.5 wavelengths but as the height is reduced, the antenna length needs to be trimmed progressively more in order to maintain resonance.
• #21: Note how the directly overhead radiation is very low when at 0.5 wavelengths. There is little difference in direct overhead radiation when height is lowered from 0.25 to 0.125 wavelengths. For NVIS, 45 deg and above, this can give 500 miles radius.
• #22: Note how that as the antenna is lowered, the pattern becomes more straight-up, it becomes a “cloud-burner” which is ideal for NVIS. Note how pattern depends less on orientation of the dipole as it is lowered, that is it becomes more “ball” like in shape with an omnidirectional pattern that is independent of antenna orientation.
• #28: The cool thing apart from the S/N ratios is the fact that MFSK uses continuous phase shifting between the tones. This allows efficient non-linear amplification to be used, such as Class C. MT63, just like PSK31, needs linear amplification if it is used.
• #29: Explain reverse flow by virtue of time moving to the right and the flow moving to the left. So this is different to the usual flow that you see with MixW and Fldigi with horizontal waterfalls.