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Topband: Take-Off Angle Question

To: <topband@contesting.com>
Subject: Topband: Take-Off Angle Question
From: "Michael Tope" <W4EF@dellroy.com>
Date: Sun, 23 Oct 2005 19:33:09 -0700
List-post: <mailto:topband@contesting.com>
I was a bit frustrated last night as I drove over to the local
club station to see if I could get in on the action to Europe
last night from here in Southern California, but I was unable
to hear a single European despite the streams of packet
spots from the west coast stations hearing gobs of Euros. 
At first I thought it might be that propagation wasn't getting 
this far south and west, but I noticed several locals were 
getting in on the action. This has left me a bit dismayed. 
I am trying to figure out if this is a SNR problem  due to high 
local QRN or if it is a take-off angle issue. Despite being the 
best location I have available, it is far from optimum for 
topband. There is a lot of line noise there as well as high 
mountains to the north. The visual horizon is about +10 to 
+11 degrees, so very low take-off angles are totally cutoff. 
Despite the high noise at this location, I have been able to 
hear and work quite a bit of DX from there. No joy to Europe, 
however. This has me wondering if these European signals 
were coming in at very low-angles. On the higher bands I have
noticed that when operating close to the MUF, you really
pay a big penalty when you are too close to the hills as
compared to nearby stations with better take-off horizons, but
I didn't think that this would as much of a factor  on 160 
meters. After last night, however, I am beginning to wonder 
if this principle doesn't apply generally for situations where
one is operating close to the MUF. Even with all the narrow
filters in and the APF on the FT-1000D cranked in, I couldn't
hear as much as a single dit from Europe last night. 

Is there anyone out here on the west coast that was 
successful in hearing those Europeans through a lousy radio 
horizon (e.g. > +10 degrees) last night? Noise I can deal with 
by building better RX antennas, moving the San Gabriel 
mountains will be a problem, however :):)

73 de Mike, W4EF....................................................





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