[time-nuts] eLORAN in the Antipodes ? (was: Re: eLORAN will be on the air GRI 99600)

[jimlux]

On 8/7/20 4:13 PM, Bill Byrom wrote:
> See this 1961 IRE paper at the NIST website:
> https://tf.nist.gov/general/pdf/2303.pdf
> IRE merged with AIEE in 1963 to form IEEE.
> 
> Figure 7 shows the calculated amplitude transfer of the ground wave signal vs frequency and distance. Note that for 100 kHz signals, the ground wave signal is reasonably strong at 2,000 miles but lousy at 5,000 miles.
> 
> As this paper notes, the sky wave reflections are delayed, and this delay depends on the ionization state of the ionosphere along the propagation path. This delay is shown in figure 2.
> 
> Figure 6 shows differences between daytime and nighttime propagation of pulsed signals. The received signal is a combination of the ground wave signal and one or more skywave signals (which are delayed with respect to the ground wave signal).
> --
> Bill Byrom N5BB
> 
> 

and such stuff is why Omega worked at VLF frequencies - none of that 
pesky skywave - lambda=30km and you're ALWAYS below ionospheric cutoff. 
Alas, they made some boneheaded mistakes like making one of the 
frequencies an exact multiple of 60Hz.

There is something positively Tesla-ian about Omega with high power low 
frequency transmitters into physically enormous antennas - like the one 
with the top hat across the fjord.  None of this tiny L-band patch 
antenna stuff inside a wristwatch.