Topband: RE: skewed paths

[Milt Jensen]

Hello all,

I believe the proof is in the pudding and the table has been set.  During
our operation from Thahtay Khun Island in the Andaman Sea as XZ0A for 4
weeks during January and February, 2000, the 160 Meter skew path was
available and evident nearly every day at our sundown (sunrise in K,W).  It
performed like clockwork, with the signals appearing from NA with a minute
of time and within a 5-10 minute window.

The first couple of days of full operation on 160 Meters we knew the signals
were coming from the SSE but we were having problems copying them on a two
wavelength long Beverage oriented specifically in that direction.  Reports
via the pilot stations indicated our transmit signal was being heard quite
well.

Based on knowledged gained from our operation from Yangon in November of
1998 as XZ1N (I installed a full size 1/2 WL dipole in the jungle at about 3
Meters AGL which heard some signals that we otherwise would not have heard)
I installed a full sized 1/2 WL dipole supported by bamboo sticks at about 6
Meters AGL across the hotel heliport.   It was broadside to the North/South
(axis = E/W).

The proof is in the results because the high angle arrival signals from the
SSE skew path received by the low dipole accounted for approximately 80% of
the 400+ NA stations that were worked on 160 Meters from XZ0A.  Even though
XZ0A operated at near the very apex of the current sunspot cycle, that
operation holds the DXpedition record for number of QSOs on 160 Meters.
Robin, WA6CDR, and I truly believe that had the operation taken place at a
sunspot low the 2,385 Topband QSOs would have totaled closer to 5,000.

The skew path does exist.  It is regular in appearance and can be duplicated
nearly at will with a high performance station.  Some nights were not too
good.  My recollection is that there was only one night out of 22
consecutive nights that we did not work a NA station.  When the path is
really good the results are outstanding.  Our very last night of operation
yielded 40+ new NA stations; some with very meager antenna systems at
inland, mid continent locations.

I don't pretend to know and understand even a small part of the physics
behind the skew path propogation.  I do know for a fact that it does exist;
that I know how to utilize it to my advantage; and that any Topband station
interested in working sunset/sunrise DX should make provision to receive AND
transmit if possible, directly along the terminator.

Now back into the woodwork.  73 de Milt, N5IA