[CQ-Contest] Can Reverse Beacon Network skimmers get overloaded?

[Hank Greeb]

I had a terrible time trying to make a "run" when I tried now and then 
during the recent CQ WPX contest.  I'd call CQ for as long as 10 
minutes, and only once did I get more than one or two contacts in a row 
from trying to "run."  I figured that propagation was weird, but 
couldn't figure out what the deal was.

After the fact I searched for my call in the past 24 hours, and found 
that I had rarely been heard calling CQ by any of the skimmers on the 
Reverse Beacon Network, and even more rarely was I more than 10 dB above 
ambient noise.  I've had considerably better results in other recent 
contest efforts.  On a typical day, if no contest is in progress, I can 
call CQ two or three times in a  minute, and I'd be heard by numerous 
skimmers, with my poorer home location.

I figured that the skimmers must have been overloaded, or the fact that 
thousands of folks were calling CQ was overloading their capacity to dig 
down for the weaker stations.

In comparing my results, hour over hour compared to last year, I made 
"about" the same number of Q's per hour - >99.44% of the S&P, so it 
would appear that, even with lousy ionospheric conditions, I was able to 
S&P with similar effectiveness.  Last year, at home, with just a low 
wire antenna, I didn't even try "running" so I don't know if I was being 
heard by the skimmers.

Is it possible that the sheer number of signals on the air make the 
skimmers less sensitive?  Or is my thinking all wrong?

72/73 de n8xx Hg
QRP >99.44% of the time
Operated WQ8RP during CQ WPX 2013