3830
[Top] [All Lists]

[3830] CQ160 CW K1LT Multi-Op HP

To: 3830@contesting.com, vkean@k1lt.com, mrrc@contesting.com
Subject: [3830] CQ160 CW K1LT Multi-Op HP
From: webform@b4h.net
Reply-to: vkean@k1lt.com, mrrc@contesting.com
Date: Mon, 28 Jan 2008 07:38:30 -0800
List-post: <mailto:3830@contesting.com>
                    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/
______________________________________________
3830 mailing list
3830@contesting.com
http://lists.contesting.com/mailman/listinfo/3830

<Prev in Thread] Current Thread [Next in Thread>
  • [3830] CQ160 CW K1LT Multi-Op HP, webform <=