TopBand: Ducting

[Bob Eldridge]

Tom said:
>I decided to post this after several e-mails about ducting.
>I'm not convinced ionospheric ducting is anything beyond pure 
>speculation. Even the experts admit there is no way to measure the 
>effect, that means it is pure conjecture. 

You will agree there is lots of conjecture in science (called 'hypothesis' I
guess.) Who measured the multiple hops? Time measurements for
round-the-world signals have shown that some signals do not bounce up and
down in the conventionally assumed manner.

With my horizon towards VK at 22 degs above the horizontal, I can believe
this morning's 439/339 with VK for ten minutes involved lots of bounces. But
I can't believe the S9+25 both ways with VK3EW on 28 May was via a ray that
bounced up and down as many times as geometry would dictate, salt water or
no salt water. There has to be another route, and SKYCOM shows a probability
of extended hops using an accredited ionospheric profile. Creating the
multiple hops usually shows the signal falling below workability before it
gets halfway along the path.
>
There ARE many occasions in the summer when the VKs and ZLs are VERY strong,
but KH6CC, /MMs and other Pacific stations are not.

73 de VE7BS, away from the shack until 7 July.
Bob Eldridge VE7BS,
Erickson Rd, Pemberton B.C. V0N 2L0
                        eldridge@whistler.net 


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