ARRL 160-Meter Contest
Call: K1LT
Operator(s): K1LT
Station: K1LT
Class: Single Op HP
QTH: Ohio EM89ps
Operating Time (hrs): 30
Radios: SO2R
Summary:
Total: QSOs = 1488 Sections = 80 Countries = 33 Total Score = 368,154
Club: Mad River Radio Club
Comments:
I've been sufficiently busy with station improvement projects this
year that I have not been able to keep up with station maintenance,
especially the care and feeding of the numerous short verticals.
Over the summer I took down the 2x2 JA-pointed BS-EF phased array that
was the prototype for the 3x2 phased array that I currently use for
"northwest" DX to reduce the number of mowing obstacles. I made use
of 2 of the elements as an end-fire array to null out my own
transmitter which made SO2V operation successful during the 2015 CQ
160 test. I left 2 of the ground systems (16 25 foot radials and the
10-foot 2x4 that holds up the PVC tubing that encloses the antenna
wire) in place with the intention of realigning (that is, moving) the
verticals for an optimal spacing and better orientation with respect
to my transmit antenna.
The first Friday crisis was to complete the integration of the audio
router and my highly hacked version of sdr-shell that I use to control
the 8 softrock equivalent radios and 14 verticals that software
converts into 4 receivers that produce 2 stereo audio streams. That
part worked out just fine. I gave up the idea of using my tablet for
that control because touch-screens are too slow.
The second Friday crisis was to finish re-erection of the 2 verticals
that help with SO2V operation. Last week while the weather was nice I
moved one of the ground systems and put the first vertical back up.
Friday of the contest I put the second vertical back up but didn't
have time to finish.
I started the contest figuring that I could do without SO2V the first
night. The first few hours were very productive with the first hour
over 150 QSOs and the next 4 of 5 hours each over 100. The first
European at 2214z was quite audible which suggested that conditions
might be good. This set my hopes of outperforming last year despite
starting without SO2V capability.
Signals were generally very good and the noise and absorption was low.
Europeans tricked in at a fairly constant rate all evening although
all were from Western Europe. However, the Eu sunrise time brought
only a few (but easily copied) additional Western Europeans. Perhaps
there was just not much DX activity.
The first night wee-hours were slow but tolerable. I managed to get
to 1000 QSOs before sunrise, beating last year by more than 100 QSOs.
Sweeping the band I found ZF2, OM, CT, and TI. I worked all of the
W/VE multipliers except WTX, AK, and NT. Since NT is never on for the
ARRL 160, only the lack of WTX was surprising. And rest in peace,
KL7RA.
Saturday I finished hooking up the verticals and cut a new "delay
line" to accommodate the new 90-degree spacing. Modeling suggests that
the wider spacing produces a broader lobe which is the point of an
omni-directional receiving antenna with a null only for my own
transmit antenna. I tuned up the phasing network which combines the
two verticals and allows a very-touchy method to null the transmitter.
The depth of the null is more than 60 db although any shakiness while
touching the controls ruins the null.
Saturday night I used the 2nd K3 and Writelog's SO2V capability to
work "fresh meat" while (slowly) running. After last year I learned
that the second radio does not hear everything, so I do need to sweep
the band on the main radio occasionally to get the juicy stuff. These
sweeps found VP9, 9A, and PJ2. I expected to use the SO2V capability
to go everywhere in the band. However, I didn't seem to be getting a
decent null of my own transmitter so I had to maintain 20 kHz or more
of separation between the transmitter and the second K3.
During the second night I began to understand a strange phenomenon of
my hybrid software and conventional station. From time to time since
last year I would observe a strong caller on the waterfall display
while at the same time hearing absolutely no audio, even though there
is audio from other signals and noise. Apparently, sometimes the
audio from the multiple receivers has just the right characteristics
such that it cancels itself. Turning off one of the receivers or even
retuning slightly sidesteps the cancellation. The trouble is that
since QSOs are short and the condition somewhat rare, its very hard to
understand just what is happening. At this point I turned off the
second set of receivers.
After the European sunrise brought a few more mostly Western Europeans
I tried mucking with the nuller on the SO2V antenna without success.
This wasted 40 minutes or so without accomplishing anything. Maybe I
missed 10 QSOs as a result.
The wee hours were very, very slow and the final sunrise burst was
also not very fast. I finished ahead of last year by only 70 QSOs and
a few multipliers.
After sleeping I looked at my notes and observed that last year I
suffered a 3-hour power outage at 0500Z the first night. That would
explain the 100 QSO difference. While I outperformed last year, that
year was defective. Furthermore, I didn't even outdo 2013.
While showering I though about the strange audio cancellation
phenomenon. I am thinking that the parallel receivers each have a
"numeric oscillator" (DSP jargon for "VFO") that is not
synchronized
between software receiver instances. This means that sometimes the
phase of signals with respect to the antenna orientation and the phase
of the numeric oscillators magically cancel each other. It also means
that more often, the audio produced by the set of receivers is not as
good as it should be (partial cancellation). I'll file a bug report.
The final result is yet another year where I have learned that station
building is never done and that postponing fixes and changes until the
next contest is not a successful strategy. Now to go relax and forget
about things ...
DX worked: 9A (2), C6, CT, DL (13), EA (2), EI, F (10), G (16), GI, GM
(2), GW (2), HA, HI, LU, LY (2), OH (2), OK (6), OM (2), ON (5), PA
(6), PJ2, PY, S5 (2), SM (2), SP, SV, TI, UR, V3, VP5, VP9, XE (3),
and ZF for 33 entities and 94 5-point QSOs.
Equipment: K3/100, P3, excessively loud Alpha 8410, K3/10; 65 foot
"T"
with 70 or so 125-foot radials, 16 23-foot verticals each with 16
23-foot radials, 2 miles of RG6, and 6 2-wire Beverages; and too many
computers and SDR pieces-parts. Also audio routing piece-parts,
homebrew SO2R box, more software, Writelog version 11 and all of its
warts (thinking of writing my own since I have so much spare time and
a track record of getting things done).
Some history:
Year DX K/VE Total K/VE DX Total
QSOs QSOs QSOs Mult Mult Score
2007 101 1452 1553 78 48 429534
2008 119 1350 1469 77 42 392105
2009 238 1447 1685 78 51 526836
2010 185 1419 1604 77 51 481664
2011 65 1288 1353 77 30 310407
2012 87 1388 1475 81 36 375687
2013 117 1378 1495 82 32 380874
2014 67 1359 1417 79 23 309570
2015 94 1394 1488 80 33 368154
Notice that the number of K/VE stations stays about the same while the
DX compliment varies. Apparently, to do markedly better I need to
increase either the number of DX stations (better everything) or the
number of K/VE stations (better SO2V or better operator) or both.
Posted using 3830 Score Submittal Forms at: http://www.3830scores.com/
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