CQ 160-Meter Contest, CW
Call: K1LT
Operator(s): K1LT, NZ8R, PACKET
Station: K1LT
Class: Multi-Op HP
QTH: Ohio
Operating Time (hrs): 38
Summary:
Total: QSOs = 1350 State/Prov = 58 Countries = 64 Total Score = 553,758
Club: Mad River Radio Club
Comments:
The 2008 CQ World Wide 160 Meter Contest started with the awful
discovery of S5 power line noise on the S and SE (150 degrees)
Beverages. Fortunately, the noise was not particularly audible in any
of the other directions. But the noise affected the phased array
receiving system. While dropping my child at her grandparents for the
weekend, I drove past some utility work that was taking place about a
mile from my QTH. I tuned the car radio to a relatively empty
frequency (1630 kHz, SWACO Radio, all trash, all the time). The noise
started rising as I approached the work area and peaked adjacent to a
pole with temporary rigging. Since the contest started in only an
hour, I didn't perceive any opportunity to affect the situation (like
crashing the car into the pole).
During the contest, I intended to test the refinements I recently
added to the Steerable Phased Array receiving system ("phased array"
for short). See k1lt.com for prior soapboxes about the development of
this system. Since the Stew Perry test, I improved the sensitivity by
replacing the op-amps in the "front-ends" with lower noise devices,
decreased the latency by numerous computer configuration changes
(process and interrupt priority, etc.), and added a headphone audio
switch box to conveniently route audio (no more mousing). I tried to
add automatic IQ balancing, but that still doesn't work correctly.
During the CQ 160, I did not notice any interference from image
signals, even though contest activity spans both halves of the 96 kHz
of spectrum the SDR presents. (I set the center frequency to 1855
kHz, which means signals above 1855 might image into the range below
1855.)
The configuration that seems to work most conveniently is to use the
Beverages and main radio for the anticipated "most difficult"
direction (usually east toward Europe) and use the steerable system
for western directions. Then, when running, I can listen in two
directions simultameously, and usually all callers are audible. The
problem is that a caller from the west who is off frequency requires
that I grab the mouse and tweak the SDR passband, while a caller from
the east who is off frequency requires that I mess with the RIT
control on the main radio. Although receiving requires more manual
effort, I don't miss callers who happen to be coming from the wrong
direction.
The first night, conditions were good. However, the power line noise
that affected the S and SE Beverages also wiped out all but NE and SW
on the phased array. So, I tried to use the phased array for Europe,
and the Beverages for other directions while operating 2-receiver
mode. However, the lack of the equivalent of RIT on the SDR receiver
made it difficult to using tuning as a signal discovery process.
After a while, I reverted to traditional single radio operation.
Sometime after sunrise Saturday morning, the noise went away.
The second night, I thought conditions were better, perhaps even
superb. I was able to run Europeans during my sunset, and again
during their sunrise. Greg, NZ8R, came over Saturday evening. He
deferred to my experience with 160 DX contesting during European
sunrise, but he did take the controls during the 0800-1100Z slow time
while I napped. Then, being of sound mind in the sunrise time frame,
I was able to run JAs for the second time ever, if you can call 5 JAs
a run. (The first time was a run of 2 JAs, last year).
While I was napping, Greg insists that he worked RV6CC at 1013Z, which
seems unlikely to me. However, I can't figure out any way a mis-copy
would result in that callsign. For now, the contact remains in my
log, although I might delete it before submitting the log to the CQ
scoring committee. We need a way of marking questionable contacts so
that the scoring committee can either delete or award them without a
penalty, or at least use them for credit for the other station.
Greg liked the phased array second receiver as well. He would like to
see a mechanism of setting the transmitter frequency via SDR-Shell.
That would make the steerable receiving system into an excellent
spotting and multiplier hunt radio. Of course, he doesn't know that
the SDR guys intend for their software to work as a transceiver with
the approriate converter and power amplifier.
The array performance seems to have reached a level where other
factors that accompany the SDR receiving system become significant.
For example, SDR-Shell needs an "incremental tuning" control, so that
the receive frequency can temporarily be adjusted for a caller that is
off frequency. Also, the filters built into SDR-core are not as sharp
as the filters in my IC765. That is, the filter skirts are wider,
even though the filter can otherwise be made very narrow (down to 10
Hz).
Theoretically, an 8 element broadside/end-fire combination (about 15
db peak to average directivity) should significantly out-perform my
Beverages (around 12 db directivity at best), but I still don't hear
it. Sometimes, the array can beat the Beverages, and sometimes it
can't.
The phased array continues to improve, but I'm not ready to start
rolling up my Beverages. Besides, one can never have too many receive
antennas (switching and searching not-withstanding).
Breakdown summary:
UTC 160 rate total
00Z 80 80 80
01Z 87 87 167
02Z 94 94 261
03Z 63 63 324
04Z 46 46 370
05Z 45 45 415
06Z 74 74 489
07Z 53 53 542
08Z 27 27 569
09Z 12 12 581
10Z 0 0 581
11Z 46 46 627
12Z 33 33 660
13Z 0 0 660
14Z 0 0 660
15Z 0 0 660
16Z 2 2 662
17Z 0 0 662
18Z 12 12 674
19Z 21 21 695
20Z 32 32 727
21Z 44 44 771
22Z 45 45 816
23Z 21 21 837
00Z 38 38 875
01Z 61 61 936
02Z 23 23 959
03Z 65 65 1024
04Z 40 40 1064
05Z 28 28 1092
06Z 29 29 1121
07Z 19 19 1140
08Z 16 16 1156
09Z 12 12 1168
10Z 10 10 1178
11Z 22 22 1200
12Z 22 22 1222
13Z 16 16 1238
14Z 21 21 1259
15Z 6 6 1265
16Z 0 0 1265
17Z 0 0 1265
18Z 0 0 1265
19Z 12 12 1277
20Z 18 18 1295
21Z 19 19 1314
22Z 11 11 1325
23Z 25 25 1350
2 point QSOs: 1057
5 point QSOs: 101
10 point QSOs: 192
DX: 4O, 5B, (5) 9A, (2) C6, CE, CN, CT, CT3, (2) CU, (2) CX, (40) DL,
(2) E7, (7) EA, EA6, EA8, (3) EI, EL, ER, ES, (2) F, (8) G, GD, (2)
GM, GW, (8) HA, HB, (2) HK, HP, HR, (5) I, (5) JA, KH6, (2) KP2, KP4,
(3) LA, LX, (4) LY, (2) OE, (5) OH, OH0, (18) OK, (6) OM, (3) ON, OZ,
P4, (7) PA, PY, (13) S5, SM, (6) SP, (2) SV, TF, TI, (4) UA, (2) UA2,
(5) UR, V3, VP9, (3) XE, (2) YL, (2) YO, (3) YU, YV, and ZF
Posted using 3830 Score Submittal Forms at: http://www.hornucopia.com/3830score/
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