[GreenKeys] 30 Meter Band Performance

[Roy Norris]

Hi Dave,

Thanks for the run down on your experiences with 30 meters.  I think
what we are seeing is that 30 meters is going to be marginal for most
near in communications because to communicate with stations out to about
800 miles, you are going to need very high angle radiation from your
antenna;  near vertical incidence.  Earlier in the sunspot cycle when
sunspot numbers and solar flux were near their peak, 30 meters would
support near vertical incidence radiation on 30 30 meters and reflect it
back to earth.  Not so now.  

For example. At this moment (12:49 CDT) the Critical Frequency for the
California area is right at 6 Mhz.  That means that anything radiated at
a near vertical incidence angle necessary for communication within 800
miles has to be 6 Mhz or lower or it will pass right through the F2
layer unreflected.    However, the MUF or Maximum Useable Frequency for
paths of 3000 KMs right now is about 18 Mhz, so anything 18 Mhz or under
would be useable for propagation across the US.  

I think what we are seeing on 30 meters these days is very variable
propagation for near vertical incidence radiation and pretty consistent
propagation for path lengths of 500 miles or more.  I am working into
Ohio just fine in the afternoon (about 500 miles).  I am only good into
the west coast in the evenings and the pacific north west is still a
problem.  

I am going to experiment with moving my antenna so that my house is not
between it and the pacific north west and also, add a parasitic element
to it to achieve some gain and improve signal to noise ratio in the
areas north and west of here.  

Near in communications on 30 meters will continue to deteriorate as we
move closer to solar minimums until even 40 meters wont support local
communications much of the time.


Best regards -- Roy, K4EEG


-----Original Message-----
From: David Ross [mailto:ross at hypertools.com] 
Sent: Thursday, May 27, 2004 10:15 AM
To: Roy Norris
Subject: Re: [GreenKeys] HoffNet Report for Wednesday, May 26th

Roy -

  Thanks for the note re hoffnet.  I am active with the clatternet crew
-  we sure see variable propagation on 30M since the sunspot peak.

  W6GER lives in the sierra foothills, maybe 50 miles east of
Sacramento.  Maybe three years ago, 30M worked for us during any
daylight hours.  Propagation then was so consistent that I could look at
my S-meter and know whether Al was running HI or LO power on his PRC-47
-  it was that dependable, almost like a telephone during daylight
hours.  W7NPA Mike, who lives about 75 air miles from me, had a
dependable & strong signal during daylight hours.
  All that has changed since the sunspot peak -  the longer W6GER
circuit is about 6 S-units down, and the short W7NPA circuit is way down
in the noise.
  30M used to be like a telephone line along the west coast -  I sure
hope that those conditions return...

  FYI, the rig here is a skintight Model 28 KSR, early (non-Tempest)
Dovetron, and a Sunair RT-9000.  The Sunair puts out 125W through it's
companion antenna coupler, to a 140" N->S wire about 20' above the
ground.

73, good luck, and thanks for your efforts
Dave Ross    N7EPI
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