[TowerTalk] Arrival angles and sunspot number

[Pete Smith]

At 10:32 AM 4/25/00 -0400, Tom Rauch wrote:
>
>> >But Pete, you have me confused. What is an isotropic source with 
>> >gain, and how can you have one near earth?
>> 
>> It's like an uggerumph, I suspect.  In VOACAP, it is called a "constant
>> gain isotrope."  If you could see it, it would look like a perfect
>> hemisphere with equal gain in every direction.
>> 
>> The beauty, of course, is that it adds no biases to the propagation
>> prediction at all, other than whatever amount of path gain you add at
>> either end.  No nulls at very low angles, or above the first lobe, to cut
>> into the received signal strength at those angles.  
>
>Great! Now I see.
>
>What did that do to the wave angle predictions?

Don't know.  I have never done the detailed comparisons that would be
required.  but for some cases, such as the yagis used on the high bands,
with the first deep null ~15-20 degrees, it's hard to imagine that the
stats weren't affected.  In the case of the inverted vees, I'd suspect it
systematically understated the low angles, wouldn't you?

The revised angle stats that Dean ran in late 1998 are on the ARRL web page
(I don't remember the exact URL, but until they get it unhacked it really
doesn't matter -- maybe TIS/AntennaBook?)


73, Pete Smith N4ZR
n4zr@contesting.com 

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