Andy,
With a slight improvement in the solar flux numbers and the longer periods of
sunlight
in the northern hemisphere, I wonder if we are at the point that 24 hour per
day will be
common using the robust weak signal digital modes?
I think you have it right Andy. Ionospheric models show that the 20 meter band
stays open much longer in summer than in winter, especially for locations
within the northern hemisphere. A few paths come close to being open for 16
hours or more.
The predictions also say that this happens regardless of where we are in the
solar cycle and it all seems to correspond well with on-air experience.
It seems logical since the summertime ionosphere is exposed to more direct
sunlight for much longer periods of time. The polar ionosphere would seem to
benefit most from summertime illumination.
It seems possible that a slight variation in the 10.7cm solar flux could have
some influence on propagation, but I would imagine it's much less significant
compared to the seasonal changes. I've learned that it doesn't always go
hand-in-hand with conditions and is often misleading...
Quoting Robert Brown (NM7M) ...
the 10.7 cm. flux has its purpose, indicating the presence of active regions,
and it is a mistake to think that changes in that flux are always associated
directly with the state of our ionosphere.
I have been able to work Europe on low power with a vertical as early as 0800
hrs, in the past month Europe did not usually open until around 1200 UTC.
That's a near perfect match to VOACAP's NY-EU predictions. The predicted 20
meter band openings start around 12:00Z in January and they slowly creep up to
08:00Z in May.
I have been heard in North Carolina at 0730 hrs UTC the past couple of
mornings using
JT65A
Could be residual F-region ionization left over from the daylight hours -
possibly Sporadic-E.
easy QSO conditions with ZL2BLQ on 20M (CW) around 0200 UTC
Nice one Andy - the time coincides with VOACAP. The band is supposed to peak
between 0200 and 0400z.
Tony -K2MO
- Original Message -
From: Andy obrien k3uka...@gmail.com
To: digitalradio digitalradio@yahoogroups.com
Sent: Sunday, May 17, 2009 4:14 AM
Subject: [digitalradio] Propagation: 20M all day now with digital modes?
With a slight improvement in the solar flux numbers and the longer
periods of sunlight in the northern hemisphere, I wonder if we are at
the point that 24 hour per day will be common using the robust weak
signal digital modes? With SF=74 and A=0 K=2 the last 2 days, I have
noted that I have been able to work Europe on low power with a
vertical as early as 0800 hrs, in the past month Europe did not
usually open until around 1200 UTC. Also, I have been heard in North
Carolina at 0730 hrs UTC the past couple of mornings using JT65A. I
have had easy QSO conditions with ZL2BLQ on 20M (CW) around 0200 UTC.
VE3ODZ-1 (FN03ha) Heard K3UK(FN02) on 14076.14 KHz -15dB at 08:06:00Z
using JT65A
WD4ELG (FM06kb) Heard K3UK(FN02) on 14076.20 KHz -13dB at 08:06Z using JT65A
Andy K3UK
